123,818

73,480

23,696

20,289

Total Current Assets

633,585

601,609

6,411,922

5,964,439

OTHER ASSETS:

Nuclear decommissioning trust

922,272

787,585

130,270

126,990

251,308

253,978

Total Other Assets

1,303,850

1,168,553

TOTAL ASSETS

8,682,851

8,079,638

CURRENT LIABILITIES:

Energy marketing contracts

Short-term debt

286,300

226,700

Accounts payable

187,428

187,954

Accrued taxes

52,451

45,534

6,353

9,670

77,437

^[1]

77,771

^[1]

40,857

33,779

Total Current Liabilities

148,347

171,222

827,287

782,846

LONG-TERM LIABILITIES:

Unamortized investment tax credits

2,491,109

2,490,871

Deferred income taxes

1,110,463

1,102,625

164,175

101,345

Accrued employee benefits

230,530

233,295

592,617

483,769

Asset retirement obligations

142,508

125,999

Total Long-Term Liabilities

74,138

66,888

5,054,823

4,882,954

COMMITMENTS AND CONTINGENCIES (See Notes 13 and 15)

TEMPORARY EQUITY (See Note 11)

3,465

Westar Energy Shareholders' Equity:

Cumulative preferred stock, par value $100 per share; authorized 600,000 shares; issued and outstanding 214,363 shares

21,436

Common stock, par value $5 per share; authorized 275,000,000 and 150,000,000 shares, respectively; issued and outstanding 125,698,396 shares and 112,128,068 shares, respectively

628,492

560,640

Paid-in capital

1,639,503

1,398,580

Retained earnings

501,216

423,647

Total Westar Energy Shareholders' Equity

2,790,647

2,404,303

Noncontrolling Interests

10,094

6,070

Total Equity

2,800,741

2,410,373

Variable Interest Entity [Member]

CURRENT ASSETS:

333,494

345,037

CURRENT LIABILITIES:

28,114

30,155

4,448

^[1]

5,064

^[1]

LONG-TERM LIABILITIES:

Summary Of Significant Accounting Policies

$ 249,283

$ 278,162

[1]	Included in accrued interest on our consolidated balance sheets.

Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Statement of Financial Position [Abstract]
Accounts receivable, allowance for doubtful accounts	$ 7,384	$ 5,729
Cumulative preferred stock, par value	$ 100	$ 100
Cumulative preferred stock, authorized	600,000	600,000
Cumulative preferred stock, issued	214,363	214,363
Cumulative preferred stock, outstanding	214,363	214,363
Common stock, par value	$ 5	$ 5
Common stock, authorized	275,000,000	150,000,000
Common stock, issued	125,698,396	112,128,068
Common stock, outstanding	125,698,396	112,128,068

Consolidated Statements Of Income (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
REVENUES	$ 2,170,991	$ 2,056,171	$ 1,858,231
OPERATING EXPENSES:
Fuel and purchased power	630,793	583,361	534,864
Operating and maintenance	557,752	520,409	516,930
Depreciation and amortization	285,322	271,937	251,534
Selling, general and administrative	184,695	207,607	199,961
Total Operating Expenses	1,658,562	1,583,314	1,503,289
INCOME FROM OPERATIONS	512,429	472,857	354,942
OTHER INCOME (EXPENSE):
Investment earnings	9,301	7,026	12,658
Other income	8,652	5,369	7,128
Other expense	(18,398)	(16,655)	(17,188)
Total Other (Expense) Income	(445)	(4,260)	2,598
Interest expense	172,460	174,941	157,360
INCOME FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	339,524	293,656	200,180
Income tax expense	103,344	85,032	58,850
INCOME FROM CONTINUING OPERATIONS	236,180	208,624	141,330
Results of discontinued operations, net of tax	0	0	33,745
NET INCOME	236,180	208,624	175,075
Less: Net income attributable to noncontrolling interests	5,941	4,728	0
NET INCOME ATTRIBUTABLE TO WESTAR ENERGY	230,239	203,896	175,075
Preferred dividends	970	970	970
NET INCOME ATTRIBUTABLE TO COMMON STOCK	229,269	202,926	174,105
BASIC AND DILUTED EARNINGS PER AVERAGE COMMON SHARE OUTSTANDING ATTRIBUTABLE TO WESTAR ENERGY (See Note 2):
Basic earnings available from continuing operations	$ 1.95	$ 1.81	$ 1.28
Discontinued operations, net of tax	$ 0.00	$ 0.00	$ 0.30
Basic earnings per common share	$ 1.95	$ 1.81	$ 1.58
Diluted earnings available from continuing operations	$ 1.93	$ 1.80	$ 1.28
Discontinued operations, net of tax	$ 0.00	$ 0.00	$ 0.30
Diluted earnings per common share	$ 1.93	$ 1.80	$ 1.58
Average equivalent common shares outstanding	116,890,552	111,629,292	109,647,689
DIVIDENDS DECLARED PER COMMON SHARE	$ 1.28	$ 1.24	$ 1.20
AMOUNTS ATTRIBUTABLE TO WESTAR ENERGY:
Income from continuing operations	230,239	203,896	141,330
Results of discontinued operations, net of tax	0	0	33,745
Net Income	$ 230,239	$ 203,896	$ 175,075

Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
CASH FLOWS FROM (USED IN) OPERATING ACTIVITIES:
Net income	$ 236,180	$ 208,624	$ 175,075
Discontinued operations, net of tax	0	0	(33,745)
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	285,322	271,937	251,534
Amortization of nuclear fuel	21,151	25,089	16,161
Amortization of deferred regulatory gain from sale-leaseback	(5,495)	(5,495)	(5,495)
Amortization of corporate-owned life insurance	25,650	20,650	22,116
Non-cash compensation	8,422	11,373	5,133
Net changes in energy marketing assets and liabilities	926	(1,284)	8,972
Net deferred income taxes and credits	111,723	120,169	46,447
Stock-based compensation excess tax benefits	(1,180)	(641)	(448)
Allowance for equity funds used during construction	(5,550)	(3,104)	(5,031)
Gain on sale of non-utility investment	(7,246)	0	0
Gain on settlement of contractual obligations with former officers	(22,039)	0	0
Changes in working capital items:
Accounts receivable	(1,638)	(11,434)	(17,159)
Fuel inventory and supplies	(21,485)	(12,266)	10,466
Prepaid expenses and other	(50,138)	8,475	(10,635)
Accounts payable	3,008	30,330	(15,115)
Accrued taxes	18,633	27,565	30,493
Other current liabilities	(107,012)	(80,660)	13,572
Changes in other assets	(10,167)	(42,544)	73,784
Changes in other liabilities	(16,369)	40,918	(87,220)
Cash Flows from Operating Activities	462,696	607,702	478,905
CASH FLOWS FROM (USED IN) INVESTING ACTIVITIES:
Additions to property, plant and equipment	(697,451)	(540,076)	(555,637)
Purchase of securities within trusts	(49,737)	(192,350)	(64,016)
Sale of securities within trusts	47,534	191,603	61,096
Investment in corporate-owned life insurance	(19,214)	(19,162)	(17,724)
Proceeds from investment in corporate-owned life insurance	1,295	2,204	1,748
Proceeds from federal grant	8,561	3,180	0
Investment in affiliated company	(1,943)	(280)	(818)
Proceeds from sale of non-utility investment	9,246	0	0
Investment in non-utility investments	(3,656)	0	0
Other investing activities	3,849	(1,164)	2,920
Cash Flows used in Investing Activities	(701,516)	(556,045)	(572,431)
CASH FLOWS FROM (USED IN) FINANCING ACTIVITIES:
Short-term debt, net	54,081	(16,060)	67,860
Proceeds from long-term debt	0	0	347,507
Retirements of long-term debt	(371)	(1,695)	(196,821)
Repayment of capital leases	(2,233)	(2,981)	(10,190)
Borrowings against cash surrender value of corporate-owned life insurance	67,562	74,134	10,299
Repayment of borrowings against cash surrender value of corporate-owned life insurance	(3,421)	(3,430)	(3,531)
Stock-based compensation excess tax benefits	1,180	641	448
Issuance of common stock	294,942	54,651	4,587
Distributions to shareholders of noncontrolling interests	(1,917)	(2,093)	0
Cash dividends paid	(138,233)	(129,146)	(122,937)
Cash Flows from (used in) Financing Activities	241,431	(54,589)	97,222
Net Cash Provided by (Used in) Investing Activities, Discontinued Operations [Abstract]
Payment of settlement to former subsidiary	0	0	(22,750)
NET INCREASE IN CASH AND CASH EQUIVALENTS	2,611	(2,932)	(19,054)
CASH AND CASH EQUIVALENTS:
Beginning of period	928	3,860	22,914
End of period	3,539	928	3,860
Variable Interest Entity [Member]
CASH FLOWS FROM (USED IN) FINANCING ACTIVITIES:
Retirements of long-term debt	$ (30,159)	$ (28,610)	$ 0

Consolidated Statements Of Changes In Equity (USD $) In Thousands, except Share data	Total	Cumulative Preferred Stock [Member]	Common Stock [Member]	Paid-In Capital [Member]	Retained Earnings [Member]	Noncontrolling Interests [Member]
Beginning Balance at Dec. 31, 2008	$ 2,207,580	$ 21,436	$ 541,556	$ 1,326,391	$ 318,197	$ 0
Beginning Balance (Shares) at Dec. 31, 2008		214,363	108,311,135
Net income	175,075	0	0	0	175,075	0
Issuance of common stock	14,373	0	3,804	10,569	0	0
Issuance of common stock (shares)		0	760,865
Preferred dividends	(970)	0	0	0	(970)	0
Dividends on common stock	(132,103)	0	0	0	(132,103)	0
Transfer to temporary equity	(20)	0	0	(20)	0	0
Amortization of restricted stock	4,524	0	0	4,524	0	0
Stock compensation and tax benefit	(1,674)	0	0	(1,674)	0	0
Ending Balance at Dec. 31, 2009	2,266,785	21,436	545,360	1,339,790	360,199	0
Ending Balance (Shares) at Dec. 31, 2009		214,363	109,072,000
Net income	208,624	0	0	0	203,896	4,728
Issuance of common stock	66,039	0	15,280	50,759	0	0
Issuance of common stock (shares)		0	3,056,068
Preferred dividends	(970)	0	0	0	(970)	0
Dividends on common stock	(139,478)	0	0	0	(139,478)	0
Transfer to temporary equity	(22)	0	0	(22)	0	0
Amortization of restricted stock	10,710	0	0	10,710	0	0
Stock compensation and tax benefit	(2,657)	0	0	(2,657)	0	0
Consolidation of noncontrolling interests	3,435	0	0	0	0	3,435
Distributions to shareholders of noncontrolling interests	(2,093)	0	0	0	0	(2,093)
Ending Balance at Dec. 31, 2010	2,410,373	21,436	560,640	1,398,580	423,647	6,070
Ending Balance (Shares) at Dec. 31, 2010		214,363	112,128,068
Net income	236,180	0	0	0	230,239	5,941
Issuance of common stock	310,933	0	67,852	243,081	0	0
Issuance of common stock (shares)		0	13,570,328
Preferred dividends	(970)	0	0	0	(970)	0
Dividends on common stock	(151,700)	0	0	0	(151,700)	0
Transfer to temporary equity	3,465	0	0	3,465	0	0
Amortization of restricted stock	7,698	0	0	7,698	0	0
Stock compensation and tax benefit	(13,321)	0	0	(13,321)	0	0
Distributions to shareholders of noncontrolling interests	(1,917)	0	0	0	0	(1,917)
Ending Balance at Dec. 31, 2011	$ 2,800,741	$ 21,436	$ 628,492	$ 1,639,503	$ 501,216	$ 10,094
Ending Balance (Shares) at Dec. 31, 2011		214,363	125,698,396

Description Of Business	12 Months Ended
Description Of Business	Dec. 31, 2011
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description Of Business	DESCRIPTION OF BUSINESS We are the largest electric utility in Kansas. Unless the context otherwise indicates, all references in this Annual Report on Form 10-K to "the company," "we," "us," "our" and similar words are to Westar Energy, Inc. and its consolidated subsidiaries. The term "Westar Energy" refers to Westar Energy, Inc., a Kansas corporation incorporated in 1924, alone and not together with its consolidated subsidiaries. We provide electric generation, transmission and distribution services to approximately 688,000 customers in Kansas. Westar Energy provides these services in central and northeastern Kansas, including the cities of Topeka, Lawrence, Manhattan, Salina and Hutchinson. Kansas Gas and Electric Company (KGE), Westar Energy's wholly owned subsidiary, provides these services in south-central and southeastern Kansas, including the city of Wichita. Both Westar Energy and KGE conduct business using the name Westar Energy. Our corporate headquarters is located at 818 South Kansas Avenue, Topeka, Kansas 66612.

Summary Of Significant Accounting Policies

12 Months Ended

Dec. 31, 2011

Accounting Policies [Abstract]

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

Principles of Consolidation

We prepare our consolidated financial statements in accordance with GAAP for the United States of America. Our consolidated financial statements include all operating divisions, majority owned subsidiaries and variable interest entities (VIEs) of which we maintain a controlling interest or are the primary beneficiary reported as a single reportable segment. Undivided interests in jointly-owned generation facilities are included on a proportionate basis. Intercompany accounts and transactions have been eliminated in consolidation.

Use of Management's Estimates

When we prepare our consolidated financial statements, we are required to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses, and related disclosure of contingent assets and liabilities at the date of our consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. We evaluate our estimates on an on-going basis, including those related to valuation of commodity contracts, depreciation, unbilled revenue, valuation of investments, valuation of our energy marketing portfolio, forecasted fuel costs included in our retail energy cost adjustment (RECA) billed to customers, income taxes, pension and post-retirement benefits, our asset retirement obligations (AROs) including the decommissioning of Wolf Creek Generating Station (Wolf Creek), environmental issues, VIEs, contingencies and litigation. Actual results may differ from those estimates under different assumptions or conditions.

Regulatory Accounting

We apply accounting standards that recognize the economic effects of rate regulation. Accordingly, we have recorded regulatory assets and liabilities when required by a regulatory order or based on regulatory precedent. See Note 3, "Rate Matters and Regulation," for additional information regarding our regulatory assets and liabilities.

Cash and Cash Equivalents

We consider investments that are highly liquid and have maturities of three months or less when purchased to be cash equivalents.

Fuel Inventory and Supplies

We state fuel inventory and supplies at average cost. Following are the balances for fuel inventory and supplies stated separately.



	As of December 31,
	2011		2010
	(In Thousands)
Fuel inventory	$	86,408	$	79,938
Supplies	142,710		126,929
Total	$	229,118	$	206,867

Property, Plant and Equipment

We record the value of property, plant and equipment, including that of VIEs, at cost. For plant, cost includes contracted services, direct labor and materials, indirect charges for engineering and supervision and an allowance for funds used during construction (AFUDC). AFUDC represents the allowed cost of capital used to finance utility construction activity. We compute AFUDC by applying a composite rate to qualified construction work in progress. We credit other income (for equity funds) and interest expense (for borrowed funds) for the amount of AFUDC capitalized as construction cost on the accompanying consolidated statements of income as follows:



	Year Ended December 31,
	2011		2010			2009
	(Dollars In Thousands)
Borrowed funds	$	5,589	$	4,295		$	4,857
Equity funds	5,550		3,104			5,031
Total	$	11,139	$	7,399		$	9,888
Average AFUDC Rates	3.6%		2.6		%	4.2		%

We charge maintenance costs and replacement of minor items of property to expense as incurred, except for maintenance costs incurred for our planned refueling and maintenance outages at Wolf Creek. As authorized by regulators, we defer and amortize to expense ratably over an 18-month operating cycle the incremental maintenance costs incurred for such outages. When a unit of depreciable property is retired, we charge to accumulated depreciation the original cost less salvage value.

Depreciation

We depreciate utility plant using a straight-line method. These rates are based on an average annual composite basis using group rates that approximated 3.0% in 2011, 2.9% in 2010 and 3.0% in 2009.

Depreciable lives of property, plant and equipment are as follows.



	Years
Fossil fuel generating facilities	7 to 78
Nuclear fuel generating facility	33 to 62
Wind generating facilities	19 to 20
Transmission facilities	15 to 67
Distribution facilities	15 to 70
Other	6 to 28

Nuclear Fuel

We record as property, plant and equipment our share of the cost of nuclear fuel used in the process of refinement, conversion, enrichment and fabrication. We reflect this at original cost and amortize such amounts to fuel expense based on the quantity of heat consumed during the generation of electricity, as measured in millions of British thermal units (MMBtu). The accumulated amortization of nuclear fuel in the reactor was $44.8 million as of December 31, 2011, and $48.0 million as of December 31, 2010. The cost of nuclear fuel charged to fuel and purchased power expense was $24.6 million in 2011, $29.2 million in 2010 and $20.1 million in 2009.

Cash Surrender Value of Life Insurance

We recorded on our consolidated balance sheets in other long-term assets the following amounts related to corporate-owned life insurance policies.



	As of December 31,
	2011			2010
	(In Thousands)
Cash surrender value of policies	$	1,345,443		$	1,280,615
Borrowings against policies	(1,208,389		)	(1,144,248		)
Corporate-owned life insurance, net	$	137,054		$	136,367

We record as income increases in cash surrender value and death benefits. We offset against policy income the interest expense that we incur on policy loans. Income from death benefits is highly variable from period to period.

Revenue Recognition

Electricity Sales

We record revenue at the time we deliver electricity to customers. We determine the amounts delivered to individual customers through systematic monthly readings of customer meters. At the end of each month, we estimate how much electricity we have delivered since the prior meter reading and record the corresponding unbilled revenue.

Our unbilled revenue estimate is affected by factors including fluctuations in energy demand, weather, line losses and changes in the composition of customer classes. We recorded estimated unbilled revenue of $54.0 million as of December 31, 2011, and $53.8 million as of December 31, 2010.

Energy Marketing Contracts

We account for energy marketing derivative contracts under the fair value method of accounting. Under this method, we recognize changes in the portfolio value as gains or losses in the period of change. With the exception of certain fuel supply and electricity contracts, which we record as regulatory assets or regulatory liabilities, we include the net change in fair value in revenues on our consolidated statements of income. We record the unrealized gains and losses as current energy marketing assets and liabilities or in other assets and other long-term liabilities on our consolidated balance sheets as appropriate. We use quoted market prices to value our energy marketing derivative contracts when such data are available. When market prices are not readily available or determinable, we use alternative approaches, such as model pricing. The prices we use to value these transactions reflect our best estimate of the fair value of these contracts. Results actually achieved from these activities could vary materially from intended results and could affect our consolidated financial results.

Normal Purchases and Normal Sales Exception

Determining whether a contract qualifies for the normal purchases and normal sales exception requires that we exercise judgment on whether the contract will physically deliver and requires that we ensure compliance with all of the associated qualification and documentation requirements. Revenues and expenses on contracts that qualify as normal purchases and normal sales are recognized when the underlying physical transaction is completed. Contracts which qualify for the normal purchases and normal sales exception are those for which physical delivery is probable, quantities are expected to be used or sold in the normal course of business over a reasonable period of time and price is not tied to an unrelated underlying derivative.

Allowance for Doubtful Accounts

We determine our allowance for doubtful accounts based on the age of our receivables. We charge receivables off when they are deemed uncollectible, which is based on a number of factors including specific facts surrounding an account and management's judgment.

Income Taxes

We use the asset and liability method of accounting for income taxes. Under this method, we recognize deferred tax assets and liabilities for the future tax consequences attributable to temporary differences between the financial statement carrying amounts and the tax basis of existing assets and liabilities. We recognize the future tax benefits to the extent that realization of such benefits is more likely than not. We amortize deferred investment tax credits over the lives of the related properties as required by tax laws and regulatory practices. We recognize production tax credits in the year that electricity is generated to the extent that realization of such benefits is more likely than not.

We record deferred tax assets to carry forward into future periods capital losses, operating losses and tax credits. However, when we believe based on available evidence that we do not, or will not, have sufficient future capital gains or taxable income in the appropriate taxing jurisdiction to realize the entire benefit during the applicable carryforward period, we record a valuation allowance against the deferred tax asset.

The application of income tax law is complex. Laws and regulations in this area are voluminous and often ambiguous. Accordingly, we must make judgments regarding income tax exposure. Interpretations of and guidance surrounding income tax laws and regulations change over time. As a result, changes in our judgments can materially affect amounts we recognize in our consolidated financial statements. See Note 10, "Taxes," for additional detail on our accounting for income taxes.

Sales Taxes

We account for the collection and remittance of sales tax on a net basis. As a result, we do not reflect sales tax in our consolidated statements of income.

Earnings Per Share

We have participating securities in the form of unvested restricted share units (RSUs) with nonforfeitable rights to dividend equivalents that receive dividends as declared on an equal basis with common shares. As a result, we apply the two-class method of computing basic and diluted earnings per share (EPS).

Under the two-class method, we reduce net income attributable to common stock by the amount of dividends declared in the current period. We allocate the remaining earnings to common stock and RSUs to the extent that each security may share in earnings as if all of the earnings for the period had been distributed. We determine the total earnings allocated to each security by adding together the amount allocated for dividends and the amount allocated for a participation feature. To compute basic EPS, we divide the earnings allocated to common stock by the weighted average number of common shares outstanding. Diluted EPS includes the effect of potential issuances of common shares resulting from our forward sale agreements, RSUs with forfeitable rights to dividend equivalents and stock options. We compute the dilutive effect of potential issuances of common shares using the treasury stock method.

The following table reconciles our basic and diluted EPS from income from continuing operations.



	Year Ended December 31,
	2011		2010		2009
	(Dollars In Thousands, Except Per Share Amounts)
Income from continuing operations	$	236,180	$	208,624	$	141,330
Less: Income attributable to noncontrolling interests	5,941		4,728		—
Income from continuing operations attributable to Westar Energy	230,239		203,896		141,330
Less: Preferred dividends	970		970		970
Income from continuing operations allocated to RSUs	772		1,259		541
Income from continuing operations attributable to common stock	$	228,497	$	201,667	$	139,819

Weighted average equivalent common shares outstanding – basic	116,890,552		111,629,292		109,647,689
Effect of dilutive securities:
RSUs	188,025		140,077		—
Forward sale agreements	1,211,645		245,496		—
Employee stock options	—		59		481
Weighted average equivalent common shares outstanding – diluted (a)	118,290,222		112,014,924		109,648,170

Earnings from continuing operations per common share, basic	$	1.95	$	1.81	$	1.28
Earnings from continuing operations per common share, diluted	$	1.93	$	1.80	$	1.28

_______________


(a)	For the years ended December 31, 2011, 2010 and 2009, we had no antidilutive shares.

Supplemental Cash Flow Information



	Year Ended December 31,
	2011			2010			2009
	(In Thousands)
CASH PAID FOR (RECEIVED FROM):
Interest on financing activities, net of amount capitalized	$	145,570		$	145,463		$	144,964
Interest on financing activities of VIEs	18,167			20,191			—
Income taxes, net of refunds	(17,519		)	(34,980		)	(7,870		)
NON-CASH INVESTING TRANSACTIONS:
Property, plant and equipment additions	105,435			64,423			21,614
Property, plant and equipment additions of VIEs	—			356,964			—
Jeffrey Energy Center (JEC) 8% leasehold interest	—			(108,706		)	—
NON-CASH FINANCING TRANSACTIONS:
Issuance of common stock for reinvested dividends and compensation plans	15,103			18,777			12,168
Debt of VIEs	—			337,951			—
Capital lease for JEC 8% leasehold interest	—			(106,423		)	—
Assets acquired through capital leases	43,011			910			2,818

Investment Earnings - Sale of Non-utility Investment

In 2011, we recorded a $7.2 million gain on the sale of a non-utility investment.

Rate Matters And Regulation

The entire disclosure for all significant accounting policies of the reporting entity.

+ References+ Details

Rate Matters And Regulation

12 Months Ended

Dec. 31, 2011

Regulated Operations [Abstract]

RATE MATTERS AND REGULATION

Regulatory Assets and Regulatory Liabilities

Regulatory assets represent incurred costs that have been deferred because they are probable of future recovery in customer prices. Regulatory liabilities represent probable future reductions in revenue or refunds to customers through the price setting process. Regulatory assets and liabilities reflected on our consolidated balance sheets are as follows.



	As of December 31,
	2011		2010
	(In Thousands)
Regulatory Assets:
Deferred employee benefit costs	$	560,915	$	431,016
Amounts due from customers for future income taxes, net	168,804		172,181
Depreciation	76,298		79,770
Debt reacquisition costs	66,856		73,099
Treasury yield hedges	33,753		—
Storm costs	25,747		34,741
Wolf Creek outage	25,033		9,637
Asset retirement obligations	22,196		21,546
Retail energy cost adjustment	19,587		—
Energy efficiency program costs	16,521		10,980
Disallowed plant costs	16,236		16,354
Ad valorem tax	6,622		5,680
Other regulatory assets	7,522		6,061
Total regulatory assets	$	1,046,090	$	861,065

Regulatory Liabilities:
Deferred regulatory gain from sale leaseback	$	97,541	$	103,036
Removal costs	82,338		70,342
Retail energy cost adjustment	25,225		16,402
La Cygne dismantling costs	15,680		13,268
Nuclear decommissioning	12,544		25,467
Other post-retirement benefits costs	11,125		6,943
Kansas tax credits	8,497		3,565
Fuel supply and electricity contracts	6,177		7,800
Ad valorem tax	—		4,934
Treasury yield hedges	—		7,711
Other regulatory liabilities	12,260		7,606
Total regulatory liabilities	$	271,387	$	267,074

Below we summarize the nature and period of recovery for each of the regulatory assets listed in the table above.

Deferred employee benefit costs: Includes $512.5 million for pension and post-retirement benefit obligations and $48.4 million for actual pension expense in excess of the amount of such expense recognized in setting our prices. During 2012, we will amortize to expense approximately $47.0 million of the benefit obligations. We expect to amortize the excess pension expense as part of resetting base prices. We do not earn a return on this asset.

Amounts due from customers for future income taxes, net: In accordance with various orders, we have reduced our prices to reflect the income tax benefits associated with certain income tax deductions, thereby passing on these benefits to customers at the time we receive them. We believe it is probable that the net future increases in income taxes payable will be recovered from customers when these temporary income tax benefits reverse in future periods. We have recorded a regulatory asset, net of the regulatory liability, for these amounts on which we do not earn a return. We also have recorded a regulatory liability for our obligation to customers for income taxes recovered in earlier periods when corporate income tax rates were higher than current income tax rates. This benefit will be returned to customers as these temporary differences reverse in future periods. The income tax-related regulatory assets and liabilities as well as unamortized investment tax credits are also temporary differences for which deferred income taxes have been provided. These items are measured by the expected cash flows to be received or settled in future prices. We do not earn a return on this asset.


-	Depreciation: Represents the difference between regulatory depreciation expense and depreciation expense we record for financial reporting purposes. We earn a return on this asset and amortize the difference over the life of the related plant.


-	Debt reacquisition costs: Includes costs incurred to reacquire and refinance debt. These costs are amortized over the term of the new debt. We do not earn a return on this asset.

Treasury yield hedges: Represents the effective portion of the losses on treasury yield hedge transactions. This amount will be amortized to interest expense over the term of the related debt. See Note 4, "Financial and Derivative Instruments, Trading Securities, Energy Marketing and Risk Management—Derivative Instruments—Cash Flow Hedges," for additional information regarding our treasury yield hedge transactions. We do not earn a return on this asset.


-	Storm costs: We accumulated and deferred for future recovery costs related to restoring our electric transmission and distribution systems from damages sustained during unusually damaging storms. We amortize these costs over periods ranging from three to five years and earn a return on a majority of this asset.


-	Wolf Creek outage: Wolf Creek incurs a refueling and maintenance outage approximately every 18 months. The expenses associated with these refueling and maintenance outages are deferred and amortized over the period between such planned outages. We do not earn a return on this asset.


-	Asset retirement obligations: Represents amounts associated with our AROs as discussed in Note 14, "Asset Retirement Obligations." We recover these amounts over the life of the related plant. We do not earn a return on this asset.

Retail energy cost adjustment: We are allowed to adjust our retail prices to reflect changes in the cost of fuel and purchased power needed to serve our customers. This item represents the actual cost of fuel consumed in producing electricity and the cost of purchased power in excess of the amounts we have collected from customers. We expect to recover in our prices this shortfall over a one-year period. For the reporting period, we had two retail jurisdictions, each with a separate cost of fuel. This resulted in us simultaneously reporting both a regulatory asset and a regulatory liability for this item. We do not earn a return on this asset.


-	Energy efficiency program costs: We accumulate and defer for future recovery costs related to our various energy efficiency programs. We will amortize such costs over a one-year period. We do not earn a return on this asset.


-	Disallowed plant costs: In 1985, the Kansas Corporation Commission (KCC) disallowed certain costs associated with the original construction of Wolf Creek. In 1987, the KCC authorized KGE to recover these costs in prices over the useful life of Wolf Creek. We do not earn a return on this asset.


-	Ad valorem tax: Represents actual costs incurred for property taxes in excess of amounts collected in our prices. We expect to recover these amounts in our prices over a on one-year period. We do not earn a return on this asset.


-	Other regulatory assets: Includes various regulatory assets that individually are small in relation to the total regulatory asset balance. Other regulatory assets have various recovery periods. We do not earn a return on any of these assets.

Below we summarize the nature and period of amortization for each of the regulatory liabilities listed in the table above.


-	Deferred regulatory gain from sale leaseback: Represents the gain KGE recorded on the 1987 sale and leaseback of its 50% interest in La Cygne Generating Station (La Cygne) unit 2. We amortize the gain over the lease term.


-	Removal costs: Represents amounts collected, but not yet spent, to dispose of plant assets that do not represent legal retirement obligations. This liability will be discharged as removal costs are incurred.

Retail energy cost adjustment: We are allowed to adjust our retail prices to reflect changes in the cost of fuel and purchased power needed to serve our customers. We bill customers based on our estimated costs. This item represents the amount we collected from customers that was in excess of our actual cost of fuel and purchased power. We will refund to customers this excess recovery over a one-year period. For the reporting period, we had two retail jurisdictions, each with a separate cost of fuel. This resulted in us simultaneously reporting both a regulatory asset and a regulatory liability for this item.


-	La Cygne dismantling costs: We are contractually obligated to dismantle a portion of La Cygne unit 2. This item represents amounts collected but not yet spent to dismantle this unit and the obligation will be discharged as we dismantle the unit.

Nuclear decommissioning: We have a legal obligation to decommission Wolf Creek at the end of its useful life. This item represents the difference between the fair value of the assets held in a decommissioning trust and the fair value of our ARO. See Note 5, "Financial Investments" and Note 14, "Asset Retirement Obligations," for information regarding our nuclear decommissioning trust (NDT) and our ARO.


-	Other post-retirement benefits costs: Represents the amount of other post-retirement benefits expense recognized in setting our prices in excess of actual other post-retirement benefits expense. At the time of a future rate review, we expect to credit this excess to customers as part of resetting our base prices.


-	Kansas tax credits: Represents Kansas tax credits on investments in utility plant. Amounts will be credited to customers subsequent to their realization over the remaining lives of the utility plant giving rise to the tax credits.


-	Fuel supply and electricity contracts: We use fair value accounting for some of our fuel supply and electricity contracts. This represents the non-cash net gain position on fuel supply and electricity contracts that are recorded at fair value. Under the RECA, fuel supply contract market gains accrue to the benefit of our customers.


-	Ad valorem tax: Represents amounts collected in our prices in excess of actual costs incurred for property taxes. We will refund to customers this excess recovery over a one-year period.

Treasury yield hedges: Represents the effective portion of the gains on treasury yield hedge transactions. This amount will be amortized to interest expense over the term of the related debt. See Note 4, "Financial and Derivative Instruments, Trading Securities, Energy Marketing and Risk Management—Derivative Instruments—Cash Flow Hedges," for additional information regarding our treasury yield hedge transactions.


-	Other regulatory liabilities: Includes various regulatory liabilities that individually are relatively small in relation to the total regulatory liability balance. Other regulatory liabilities will be credited over various periods.

KCC Proceedings

General and Abbreviated Rate Reviews

On August 25, 2011, we filed an application with the KCC proposing a $90.8 million increase in our annual retail prices. The primary drivers for the proposed increase were higher costs related to tree trimming, regulatory compliance, operating Wolf Creek and employee benefits. On February 6, 2012, we entered into a definitive Stipulation and Agreement agreed to or not opposed by all parties to this proceeding, with the exception of a consumer advocate. The settlement provides for a $50.0 million increase in our annual retail prices and is subject to KCC approval. Technical hearings commenced on February 13, 2012. We expect the KCC to issue an order on our request in April 2012.

On January 27, 2010, the KCC issued an order allowing us to adjust our prices to include costs associated with investments in natural gas and wind generation facilities. The new prices were effective February 2010 and were expected to increase our annual retail revenues by approximately $17.1 million.

On January 21, 2009, the KCC issued an order expected to increase our annual retail revenues by approximately $130.0 million to reflect investments in natural gas generation facilities, wind generation facilities and other capital projects, costs to repair damage to our electrical system, which were previously deferred as a regulatory asset, higher operating costs in general and an updated capital structure. The new prices were effective February 3, 2009.

Environmental Costs

On February 23, 2011, Kansas City Power & Light Company (KCPL) filed an application requesting that the KCC predetermine the ratemaking principles for and determine the appropriateness of approximately $1.2 billion of environmental upgrades proposed for La Cygne to comply with environmental regulations. We have a 50% interest in La Cygne and intervened in the proceeding. On August 19, 2011, the KCC issued an order ruling that the decision to make the upgrades is prudent and the $1.2 billion project cost estimate is reasonable. The KCC denied our request to collect our approximately $600.0 million share of the costs of the environmental upgrades through our environmental cost recovery rider (ECRR). However, in the Stipulation and Agreement noted above, all parties to the agreement agreed that we may file an abbreviated rate review to update our prices to include capital costs associated with the project, which we plan to do.

We also make annual filings with the KCC to adjust our prices to include costs associated with investments in air quality equipment made during the prior year. Following is additional information regarding such price adjustments.


•	On May 27, 2011, the KCC issued an order allowing us to increase our annual retail revenues by approximately $10.4 million effective June 1, 2011.


•	On May 25, 2010, the KCC issued an order allowing us to increase our annual retail revenues by approximately $13.8 million effective June 1, 2010.


•	On May 29, 2009, the KCC issued an order allowing us to increase our annual retail revenues by approximately $32.5 million effective June 1, 2009.

Transmission Costs

We make annual filings with the KCC to adjust our prices to include updated transmission costs as reflected in our transmission formula rate discussed below. Following is information regarding such price adjustments.


•	On December 30, 2011, the KCC issued an order allowing us to increase our annual retail revenues by approximately $17.4 million effective April 14, 2011.


•	On June 11, 2010, the KCC issued an order allowing us to increase our annual retail revenues by approximately $6.4 million effective March 16, 2010.


•	On March 6, 2009, the KCC issued an order allowing us to increase our annual retail revenues by approximately $31.8 million effective March 13, 2009.

Energy Efficiency

We make annual filings with the KCC to adjust our prices to include previously deferred amounts associated with various energy efficiency programs. Following is information regarding such price adjustments.


•	On October 27, 2011, the KCC issued an order allowing us to increase our annual retail revenues by approximately $4.9 million to recover additional deferred amounts effective November 2011.


•	On October 29, 2010, the KCC issued an order allowing us to recover approximately $5.8 million of previously deferred amounts effective November 2010.

Other

On September 11, 2009, the KCC issued an order, effective January 1, 2009, allowing us to establish a regulatory asset or liability to track the cumulative difference between current year pension and post-retirement benefits expense and the amount of such expense recognized in setting our prices. We will accumulate such regulatory asset or liability between general rate reviews and expect to amortize the accumulated amount as part of resetting our base prices during general rate reviews.

FERC Proceedings

On October 15 of each year, we post an updated transmission formula rate that includes projected transmission capital expenditures and operating costs for the following year. This rate provides the basis for our annual request with the KCC to adjust our retail prices to include updated transmission costs as noted above. Below is additional information regarding our transmission formula rates posted over the last few years.


•	Our transmission formula rate that includes projected 2012 costs was effective January 1, 2012, and is expected to increase our annual transmission revenues by approximately $38.2 million.


•	Our transmission formula rate that included projected 2011 costs was effective January 1, 2011, and was expected to increase our annual transmission revenues by approximately $15.9 million.


•	Our transmission formula rate that included projected 2010 costs was effective January 1, 2010, and was expected to increase our annual transmission revenues by approximately $16.8 million.

On January 12, 2010, the Federal Energy Regulatory Commission (FERC) issued an order accepting our request to implement a cost-based formula rate for electricity sales to wholesale customers. The use of a cost-based formula rate allows us to annually adjust our prices to reflect changes in our cost of service. The cost-based formula rate was effecti

Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management

12 Months Ended

Dec. 31, 2011

Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Abstract]

Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management

FINANCIAL AND DERIVATIVE INSTRUMENTS, TRADING SECURITIES, ENERGY MARKETING AND RISK MANAGEMENT

Values of Financial and Derivative Instruments

GAAP establishes a hierarchal framework for disclosing the transparency of the inputs utilized in measuring assets and liabilities at fair value. Our assessment of the significance of a particular input to the fair value measurement requires judgment and may affect the classification of assets and liabilities within the fair value hierarchy levels. The three levels of the hierarchy and examples are as follows:


•	Level 1 - Quoted prices are available in active markets for identical assets or liabilities. The types of assets and liabilities included in level 1 are highly liquid and actively traded instruments with quoted prices, such as equities listed on public exchanges and exchange-traded futures contracts.

•

Level 2 - Pricing inputs are not quoted prices in active markets, but are either directly or indirectly observable. The types of assets and liabilities included in level 2 are typically measured at net asset value, comparable to actively traded securities or contracts, such as treasury securities with pricing interpolated from recent trades of similar securities, or priced with models using highly observable inputs, such as commodity options priced using observable forward prices and volatilities.


•	Level 3 - Significant inputs to pricing have little or no transparency. The types of assets and liabilities included in level 3 are those with inputs requiring significant management judgment or estimation, such as the complex and subjective models and forecasts used to determine the fair value of options, real estate investments and long-term electricity supply contracts.

We record cash and cash equivalents, short-term borrowings and variable rate debt on our consolidated balance sheets at cost, which approximates fair value. We measure the fair value of fixed rate debt based on quoted market prices for the same or similar issues or on the current rates offered for instruments of the same remaining maturities and redemption provisions. The recorded amount of accounts receivable and other current financial instruments approximates fair value.

All of our level 2 investments are held in investment funds that are measured at fair value using daily net asset values as reported by the trustee. In addition, we maintain certain level 3 investments in private equity and real estate securities that require significant unobservable market information to measure the fair value of the investments. The fair value of private equity investments is measured by utilizing both market- and income-based models, public company comparables, at cost or at the value derived from subsequent financings. Adjustments are made when actual performance differs from expected performance; when market, economic or company-specific conditions change; and when other news or events have a material impact on the security. To measure the fair value of real estate securities we use a combination of market- and income-based models utilizing market discount rates, projected cash flows and the estimated value into perpetuity.

Energy marketing contracts can be exchange-traded or traded over-the-counter (OTC). Fair value measurements of exchange-traded contracts typically utilize quoted prices in active markets. OTC contracts are valued using market transactions and other market evidence whenever possible, including market-based inputs to models, model calibration to market clearing transactions or alternative pricing sources with reasonable levels of price transparency. Valuation models require a variety of inputs, including contractual terms, market prices, yield curves, credit curves, nonperformance risk, measures of volatility and correlations of such inputs. Certain OTC contracts trade in less liquid markets with limited pricing information and the determination of fair value for these derivatives is inherently more subjective. In these situations, estimates by management are a significant input. See "-Recurring Fair Value Measurements" and "-Derivative Instruments" below for additional information.

We measure fair value based on information available as of the measurement date. The following table provides the carrying values and measured fair values of our financial instruments.



	Carrying Value				Fair Value
	As of December 31,
	2011		2010		2011		2010
	(In Thousands)
Fixed-rate debt	$	2,373,063	$	2,373,373	$	2,623,993	$	2,570,648
Fixed-rate debt of VIEs	275,738		308,317		306,027		341,328

Recurring Fair Value Measurements

The following table provides the amounts and their corresponding level of hierarchy for our assets and liabilities that are measured at fair value.



As of December 31, 2011	Level 1		Level 2		Level 3		Total
	(In Thousands)
Assets:
Energy Marketing Contracts	$	—	$	2,401	$	13,330	$	15,731
Nuclear Decommissioning Trust:
Domestic equity	—		53,186		3,931		57,117
International equity	—		22,307		—		22,307
Core bonds	—		20,171		—		20,171
High-yield bonds	—		10,969		—		10,969
Emerging market bonds	—		5,309		—		5,309
Combination debt/equity fund	—		7,251		—		7,251
Real estate securities	—		—		7,095		7,095
Cash equivalents	51		—		—		51
Total Nuclear Decommissioning Trust	51		119,193		11,026		130,270
Trading Securities:
Domestic equity	—		21,175		—		21,175
International equity	—		4,896		—		4,896
Core bonds	—		13,961		—		13,961
Cash equivalents	169		—		—		169
Total Trading Securities	169		40,032		—		40,201
Total Assets Measured at Fair Value	$	220	$	161,626	$	24,356	$	186,202

Liabilities:
Energy Marketing Contracts	$	—	$	2,475	$	3,878	$	6,353
Treasury Yield Hedges	—		34,025		—		34,025
Total Liabilities Measured at Fair Value	$	—	$	36,500	$	3,878	$	40,378

As of December 31, 2010
Assets:
Energy Marketing Contracts	$	2,432	$	6,258	$	13,787	$	22,477
Nuclear Decommissioning Trust:
Domestic equity	—		60,586		2,867		63,453
International equity	—		18,966		—		18,966
Core bonds	—		31,906		—		31,906
High-yield bonds	—		9,267		305		9,572
Real estate securities	—		—		3,049		3,049
Cash equivalents	44		—		—		44
Total Nuclear Decommissioning Trust	44		120,725		6,221		126,990
Trading Securities:
Domestic equity	—		21,207		—		21,207
International equity	—		5,128		—		5,128
Core bonds	—		13,077		—		13,077
Total Trading Securities	—		39,412		—		39,412
Treasury Yield Hedges	—		7,711		—		7,711
Total Assets Measured at Fair Value	$	2,476	$	174,106	$	20,008	$	196,590

Liabilities:
Energy Marketing Contracts	$	1,888	$	5,820	$	1,972	$	9,680

We do not offset the fair value of energy marketing contracts executed with the same counterparty. As of December 31, 2011, we had no right to reclaim cash collateral and had recorded $2.9 million for our obligation to return cash collateral. As of December 31, 2010, we had no right to reclaim cash collateral and had recorded $0.7 million for our obligation to return cash collateral.

The following table provides reconciliations of assets and liabilities measured at fair value using significant level 3 inputs for the years ended December 31, 2011 and 2010.



	Energy Marketing Contracts, net				Nuclear Decommissioning Trust									Net Balance
	Energy Marketing Contracts, net				Domestic Equity			High-yield Bonds			Real Estate Securities			Net Balance
	(In Thousands)
Balance as of December 31, 2010	$	11,815			$	2,867		$	305		$	3,049		$	18,036
Total realized and unrealized gains (losses) included in:
Earnings (a)	603				—			—			—			603
Regulatory assets	(1,450		)	(b)	—			—			—			(1,450		)
Regulatory liabilities	2,993			(b)	479			—			670			4,142
Purchases	(6,145		)		608			—			3,455			(2,082		)
Sales	1,022				(23		)	(305		)	(79		)	615
Settlements	614				—			—			—			614
Balance as of December 31, 2011	$	9,452			$	3,931		$	—		$	7,095		$	20,478

Balance as of December 31, 2009	$	4,310			$	2,262		$	5,741		$	3,635		$	15,948
Total realized and unrealized gains (losses) included in:
Earnings (a)	(2,585		)		—			—			—			(2,585		)
Regulatory assets	3,311			(b)	—			—			—			3,311
Regulatory liabilities	8,148			(b)	16			367			(586		)	7,945
Purchases, issuances and settlements, net	(1,369		)		589			(5,803		)	—			(6,583		)
Balance as of December 31, 2010	$	11,815			$	2,867		$	305		$	3,049		$	18,036

_______________


(a)	Unrealized gains and losses included in earnings are reported in revenues.


(b)	Includes changes in the fair value of certain fuel supply and electricity contracts.

Portions of the gains and losses contributing to changes in net assets in the above table are unrealized. The following table summarizes the unrealized gains and losses we recorded on our consolidated financial statements during the years ended December 31, 2011 and 2010, attributed to level 3 assets and liabilities.



	Year Ended December 31, 2011
	Energy Marketing Contracts, net				Nuclear Decommissioning Trust
	Energy Marketing Contracts, net				Domestic Equity		High-yield Bonds			Real Estate Securities			Net Balance
	(In Thousands)
Total unrealized gains (losses) included in:
Earnings (a)	$	(898	)		$	—	$	—		$	—		$	(898	)
Regulatory assets	(747		)	(b)	—		—			—			(747		)
Regulatory liabilities	1,736			(b)	456		—			591			2,783
Total	$	91			$	456	$	—		$	591		$	1,138

	Year Ended December 31, 2010
Total unrealized gains (losses) included in:
Earnings (a)	$	(1,441	)		$	—	$	—		$	—		$	(1,441	)
Regulatory assets	180			(b)	—		—			—			180
Regulatory liabilities	2,633			(b)	23		(31		)	(586		)	2,039
Total	$	1,372			$	23	$	(31	)	$	(586	)	$	778

_______________


(a)	Unrealized gains and losses included in earnings are reported in revenues.


(b)	Includes changes in the fair value of certain fuel supply and electricity contracts.

Some of our investments in the NDT and our trading securities portfolio do not have readily determinable fair values and are either with investment companies or companies that follow accounting guidance consistent with investment companies. In certain situations these investments may have redemption restrictions. The following table provides additional information on these investments.



	As of December 31, 2011				As of December 31, 2010				As of December 31, 2011
	Fair Value		Unfunded Commitments		Fair Value		Unfunded Commitments		Redemption Frequency	Length of Settlement
	(In thousands)
Nuclear Decommissioning Trust:
Domestic equity	$	3,931	$	1,914	$	2,867	$	2,523	(a)	(a)
High-yield bonds	—		—		305		—		(b)	(b)
Real estate securities	7,095		—		3,049		—		(c)	(c)
Total Nuclear Decommissioning Trust	$	11,026	$	1,914	$	6,221	$	2,523

Trading Securities:
Domestic equity	$	21,175	$	—	$	21,207	$	—	Upon Notice	1 day
International equity	4,896		—		5,128		—		Upon Notice	1 day
Core bonds	13,961		—		13,077		—		Upon Notice	1 day
Total Trading Securities	40,032		—		39,412		—
Total	$	51,058	$	1,914	$	45,633	$	2,523

_______________


(a)	This investment is in two long-term private equity funds that do not permit early withdrawal. Our investments in these funds cannot be distributed until the underlying investments have been liquidated which may take years from the date of initial liquidation. One fund has begun making distributions and we expect the other to begin in 2013.


(b)	We completely settled this fund 2011.


(c)	The nature of this investment requires relatively long holding periods which do not necessarily accommodate ready liquidity. In addition, adverse financial conditions affecting residential and commercial real estate markets have further limited liquidity associated with this investment.

Nonrecurring Fair Value Measurements

We have recognized legal obligations associated with the disposal of long-lived assets that result from the acquisition, construction, development or normal operations of such assets. In 2010 we did not incur any additional AROs. In 2011, we incurred $9.9 million of additional AROs to reflect revisions to the estimated cost to decommission Wolf Creek. We initially record AROs at fair value for the estimated cost to satisfy the retirement obligation.

The fair value is measured by estimating the cost to satisfy the retirement obligation then discounting that value at a risk- and inflation-adjusted rate. To determine the cost to satisfy the retirement obligation, we must estimate the cost of basic inputs such as labor, energy, materials and disposal and make assumptions on the method of disposal or decommissioning. To determine the appropriate discount rate, we use inputs such as inflation rates, short and long-term yields for U.S. government securities and our nonperformance risk. The current estimate to decommission Wolf Creek assumes that the Department of Energy will have removed all of Wolf Creek's spent nuclear fuel and high-level radioactive waste by the time the rest of the plant has been decommissioned. Due to the significant unobservable inputs required in our measurement, we have determined that our fair value measurements of our AROs are level 3 in the fair value hierarchy. For additional information on our AROs, see Note 14, "Asset Retirement Obligations."

Derivative Instruments

Cash Flow Hedges

We have entered into treasury yield hedge transactions for a total notional amount of $125.0 million in an attempt to manage our interest rate risk associated with a future anticipated issuance of fixed rate debt. Such transactions are designated and qualify as cash flow hedges and are measured at fair value by estimating the net present value of a series of payments using market-based models with observable inputs such as the spread between the 30-year U.S. Treasury bill yield and the contracted, fixed yield. As a result of regulatory accounting treatment, we report the effective portion of the gains or losses on these derivative instruments as a regulatory liability or regulatory asset and will amortize such amounts to interest expense over the term of the related debt. As of December 31, 2011, we had recorded $34.0 million in other current liabilities on our consolidated balance sheet to reflect the fair value of the treasury yield hedge transactions and $33.8 million in long-term regulatory assets to reflect the effective portion of the losses on these transactions. During 2011, we recorded $0.2 million of hedge ineffectiveness losses in interest expense on our consolidated statements of income. As of December 31, 2010, we had recorded $7.7 million in other assets to reflect the fair value of these transactions and recorded this same amount in long-term regulatory liabilities to reflect the effective portion of the gains on these transactions. On January 20, 2012, we settled the treasury yield hedge transactions for a total cost of $27.5 million. The cost of the hedge transactions will be amortized to interest expense over the term of the related debt.

Commodity Contracts

We engage in both financial and physical trading with the goal of managing our commodity price risk, enhancing system reliability and increasing profits. We trade electricity and other energy-related products using a variety of financial instruments, which may include futures contracts, options, swaps and physical commodity contracts.

We classify these commodity derivative instruments as energy marketing contracts on our consolidated balance sheets. We report energy marketing contracts representing unrealized gain positions as assets; energy marketing contracts representing unrealized loss positions are reported as liabilities. With the exception of certain fuel supply and electricity contracts, which we record as regulatory assets or regulatory liabilities, we include the change in the fair value of energy marketing contracts in revenues on our consolidated statements of income.

The following table presents the fair value of commodity derivative instruments reflected on our consolidated balance sheets.



Commodity Derivatives Not Designated as Hedging Instruments as of December 31, 2011
Asset Derivatives			Liability Derivatives
Balance Sheet Location	Fair Value		Balance Sheet Location	Fair Value
	(In Thousands)			(In Thousands)
Current assets:			Current liabilities:
Energy marketing contracts	$	8,180	Energy marketing contracts	$	6,353
Other assets:
Other	7,551
Total	$	15,731

Commodity Derivatives Not Designated as Hedging Instruments as of December 31, 2010
Asset Derivatives			Liability Derivatives
Balance Sheet Location	Fair Value		Balance Sheet Location	Fair Value
	(In Thousands)			(In Thousands)
Current assets:			Current liabilities:
Energy marketing contracts	$	13,005	Energy marketing contracts	$	9,670
Other assets:			Long-term liabilities:
Other	9,472		Other	10
Total	$	22,477	Total	$	9,680

The following table presents how changes in the fair value of commodity derivative instruments affected our consolidated financial statements for the years ended December 31, 2011 and 2010.



	Year Ended December 31, 2011					Year Ended December 31, 2010
Location	Net Gain Recognized		Net Loss Recognized			Net Gain Recognized
	(In Thousands)
Revenues increase	$	1,569	$	—		$	712
Regulatory assets increase (decrease)	—		374			(7,604		)
Regulatory liabilities (decrease) increase	—		(1,623		)	1,799

As of December 31, 2011 and 2010, we had under contract the following commodity derivatives.



		Net Quantity as of
	Unit of Measure	December 31, 2011	December 31, 2010
Electricity	MWh	1,834,253	2,791,966
Natural Gas	MMBtu	1,467,500	1,150,000

Net open positions exist, or are established, due to the origination of new transactions and our assessment of, and response to, changing market conditions. To the extent we have net open positions, we are exposed to the risk that changing market prices could have a material impact on our consolidated financial results.

Energy Marketing Activities

Within our energy trading portfolio, we may establish certain positions intended to economically hedge a portion of physical sale or purchase contracts and we may enter into certain positions attempting to take advantage of market trends and conditions. We use the term economic hedge to mean a strategy intended to manage risks of volatility in prices or rate movements on selected assets, liabilities or anticipated transactions by creating a relationship in which gains or losses on derivative instruments are expected to offset the losses or gains on the assets, liabilities or anticipated transactions exposed to such market risks.

Price Risk

We use various types of fuel, including coal, natural gas, uranium, diesel and oil, to operate our plants and also purchase power to meet customer demand. Our prices and consolidated financial results are exposed to market risks from commodity price changes for electricity and other energy-related products as well as interest rates. Volatility in these markets impacts our costs of purchased power, costs of fuel for our generating plants and our participation in energy markets. We strive to manage our customers' and our exposure to these market risks through regulatory, operating and financing activities and, when we deem appropriate, we economically hedge a portion of these risks through the use of derivative financial instruments for non-trading purposes.

Interest Rate Risk

We have entered into numerous fixed and variable rate debt obligations. For details, see Note 9, "Long-Term Debt." We manage our interest rate risk related to these debt obligations by limiting our exposure to variable interest rate debt, diversifying maturity dates and entering into treasury yield hedge transactions. We may also use other financial derivative instruments such as interest rate swaps.

Credit Risk

In addition to commodity price risk, we are exposed to credit risks associated with the financial condition of counterparties, product location (basis) pricing differentials, physical liquidity constraints and other risks. Declines in the creditworthiness of our counterparties could have a material impact on our overall exposure to credit risk. We maintain credit policies with regard to our counterparties intended to reduce our overall credit risk exposure to a level we deem acceptable and include the right to offset derivative assets and liabilities by counterparty.

We have derivative instruments with commodity exchanges and other counterparties that do not contain objective credit-risk-related contingent features. However, certain of our derivative instruments contain collateral provisions subject to credit agency ratings of our senior unsecured debt. If our senior unsecured debt ratings were to decrease or fall below investment grade, the counterparties to the derivative instruments, pursuant to the provisions, could require collateralization on derivative instruments. The aggregate fair value of all derivative instruments with objective credit-risk-related contingent features that were in a liability position as of December 31, 2011 and 2010, was $3.1 million and $1.6 million, respectively, for which we had posted no collateral as of either date. If all credit-risk-related contingent features underlying these agreements had been triggered as of December 31, 2011 and 2010, we would have been required to provide to our counterparties $0.5 million and $1.6 million, respectively, of additional collateral after taking into consideration the offsetting impact of derivative assets and net accounts receivable.

Financial Investments

12 Months Ended

Dec. 31, 2011

Investments [Abstract]

Financial Investments

FINANCIAL INVESTMENTS

We report some of our investments in equity and debt securities at fair value and use the specific identification method to determine their realized gains and losses. We classify these investments as either trading securities or available-for-sale securities as described below.

Trading Securities

We hold equity and debt investments in a trust used to fund retirement benefits that we classify as trading securities. We include unrealized gains or losses on these securities in investment earnings on our consolidated statements of income. For the years ended December 31, 2011, 2010 and 2009, we recorded unrealized gains of $0.3 million, $4.3 million and $11.3 million, respectively.

Available-for-Sale Securities

We hold investments in equity, debt and real estate securities in a trust for the purpose of funding the decommissioning of Wolf Creek. We have classified these investments as available-for-sale and have recorded all such investments at their fair market value as of December 31, 2011 and 2010. The core bond fund has a requirement that at least 80% of funds are invested in investment grade U.S. corporate and government fixed income securities, including mortgage-backed securities. As of December 31, 2011, the fair value of available-for-sale debt securities in the core, high-yield and emerging market bond funds was $36.4 million. As of December 31, 2011, the NDT did not have investments in debt securities outside of investment funds.

Using the specific identification method to determine cost, we realized a $1.3 million gain in 2011, a $13.2 million gain in 2010 and a $7.8 million loss in 2009 on our available-for-sale securities. We record net realized and unrealized gains and losses in regulatory liabilities on our consolidated balance sheets. This reporting is consistent with the method we use to account for the decommissioning costs we recover in our prices. Gains or losses on assets in the trust fund are recorded as increases or decreases to regulatory liabilities and could result in lower or higher funding requirements for decommissioning costs, which we believe would be reflected in the prices paid by our customers.

The following table presents the cost, gross unrealized gains and losses, fair value and allocation of investments in the NDT fund as of December 31, 2011 and 2010.



			Gross Unrealized
Security Type	Cost		Gain		Loss			Fair Value		Allocation
	(In Thousands)
As of December 31, 2011
Domestic equity	$	55,357	$	1,760	$	—		$	57,117	44	%
International equity	24,501		—		(2,194		)	22,307		17	%
Core bonds	19,771		400		—			20,171		16	%
High-yield bonds	11,046		—		(77		)	10,969		8	%
Emerging market bonds	5,301		8		—			5,309		4	%
Combination debt/equity fund	7,524		—		(273		)	7,251		6	%
Real estate securities	9,662		—		(2,567		)	7,095		5	%
Cash equivalents	51		—		—			51		<1%
Total	$	133,213	$	2,168	$	(5,111	)	$	130,270	100	%

As of December 31, 2010
Domestic equity	$	58,592	$	4,972	$	(111	)	$	63,453	50	%
International equity	17,249		1,717		—			18,966		15	%
Core bonds	32,054		—		(148		)	31,906		25	%
High-yield bonds	9,086		486		—			9,572		8	%
Real estate securities	6,207		—		(3,158		)	3,049		2	%
Cash equivalents	44		—		—			44		<1%
Total	$	123,232	$	7,175	$	(3,417	)	$	126,990	100	%

The following table presents the fair value and the gross unrealized losses of the available-for-sale securities held in the NDT fund aggregated by investment category and the length of time that individual securities have been in a continuous unrealized loss position as of December 31, 2011 and 2010.



	Less than 12 Months					12 Months or Greater					Total
	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
	(In Thousands)
As of December 31, 2011
International equity	22,307		(2,194		)	—		—			22,307		(2,194		)
High-yield bonds	10,969		(77		)	—		—			10,969		(77		)
Combination debt/equity fund	7,251		(273		)	—		—			7,251		(273		)
Real estate securities	—		—			7,095		(2,567		)	7,095		(2,567		)
Total	$	40,527	$	(2,544	)	$	7,095	$	(2,567	)	$	47,622	$	(5,111	)

As of December 31, 2010
Domestic equity	$	2,867	$	(111	)	$	—	$	—		$	2,867	$	(111	)
Core bonds	31,906		(148		)	—		—			31,906		(148		)
Real estate securities	—		—			3,049		(3,158		)	3,049		(3,158		)
Total	$	34,773	$	(259	)	$	3,049	$	(3,158	)	$	37,822	$	(3,417	)

Property, Plant And Equipment

12 Months Ended

Dec. 31, 2011

Public Utilities, Property, Plant and Equipment [Abstract]

Property, Plant and Equipment

PROPERTY, PLANT AND EQUIPMENT

The following is a summary of our property, plant and equipment balance.



	As of December 31,
	2011			2010
	(In Thousands)

Electric plant in service	$	8,703,278		$	8,254,884
Electric plant acquisition adjustment	802,318			802,318
Accumulated depreciation	(3,703,372		)	(3,563,566		)
	5,802,224			5,493,636
Construction work in progress	534,003			392,701
Nuclear fuel, net	75,695			78,102
Net property, plant and equipment	$	6,411,922		$	5,964,439

The following is a summary of property, plant and equipment of VIEs.



	As of December 31,
	2011			2010
	(In Thousands)

Electric plant of VIEs	$	543,548		$	543,593
Accumulated depreciation of VIEs	(210,054		)	(198,556		)
Net property, plant and equipment of VIEs	$	333,494		$	345,037

We recorded depreciation expense on property, plant and equipment of $262.6 million in 2011, $249.2 million in 2010 and $228.6 million in 2009. Approximately $9.8 million and $9.7 million of depreciation expense in 2011 and 2010, respectively, was attributable to property, plant and equipment of VIEs.

Joint Ownership of Utility Plants

The entire disclosure for long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale. Examples include land, buildings, machinery and equipment, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software. This disclosure may include property plant and equipment accounting policies and methodology, a schedule of property, plant and equipment gross, additions, deletions, transfers and other changes, depreciation, depletion and amortization expense, net, accumulated depreciation, depletion and amortization expense and useful lives, income statement disclosures, assets held for sale and public utility disclosures.

+ References+ Details

Joint Ownership of Utility Plants

12 Months Ended

Dec. 31, 2011

Regulated Operations [Abstract]

JOINT OWNERSHIP OF UTILITY PLANTS

Under joint ownership agreements with other utilities, we have undivided ownership interests in four electric generating stations. Energy generated and operating expenses are divided on the same basis as ownership with each owner reflecting its respective costs in its statements of income and each owner responsible for its own financing. Information relative to our ownership interests in these facilities as of December 31, 2011, is shown in the table below.



Plant	In-Service Dates	Investment		Accumulated Depreciation		Construction Work in Progress		Net MW	Ownership Percentage
		(Dollars in Thousands)
La Cygne unit 1 (a)	June 1973	$	332,862	$	148,890	$	68,724	368	50
JEC unit 1 (a)	July 1978	488,180		207,206		49,755		666	92
JEC unit 2 (a)	May 1980	508,327		186,660		—		667	92
JEC unit 3 (a)	May 1983	677,277		268,909		6,770		672	92
Wolf Creek (b)	Sept. 1985	1,515,165		732,651		37,740		547	47
State Line (c)	June 2001	112,024		45,841		1,579		201	40
Total		$	3,633,835	$	1,590,157	$	164,568	3,121

_______________


(a)	Jointly owned with KCPL. Our 8% leasehold interest in JEC that is consolidated as a VIE is reflected in the net megawatts (MW) and ownership percentage provided above, but not in the other amounts in the table.


(b)	Jointly owned with KCPL and Kansas Electric Power Cooperative, Inc.

We include in operating expenses on our consolidated statements of income our share of operating expenses of the above plants. Our share of other transactions associated with the plants is included in the appropriate classification on our consolidated financial statements.

In addition, we also consolidate a VIE that holds our 50% leasehold interest in La Cygne unit 2, which represents 343 MW of net capacity. The VIE's investment in the 50% interest was $392.1 million and accumulated depreciation was $173.1 million as of December 31, 2011. We include these amounts in property, plant and equipment of variable interest entities, net on our consolidated balance sheets. See Note 17, "Variable Interest Entities," for additional information about VIEs.

Short-Term Debt

12 Months Ended

Dec. 31, 2011

Debt Disclosure [Abstract]

Short-Term Debt

SHORT-TERM DEBT

On December 9, 2011, Westar Energy entered into a commercial paper program pursuant to which it may issue commercial paper up to a maximum aggregate amount outstanding at any one time of $1.0 billion. This program is supported by Westar Energy's revolving credit facilities described below. Maturities of commercial paper issuances may not exceed 365 days from the date of issuance and proceeds from such issuances will be used to repay borrowings under Westar Energy's revolving credit facilities, for capital expenditures and/or for other general corporate purposes. As of December 31, 2011, Westar Energy had no commercial paper outstanding.

On September 29, 2011, Westar Energy refinanced its existing $730.0 million revolving credit facility with a new facility in the same amount. The commitments under the new facility terminate on September 29, 2016. As long as there is no default under the facility, Westar Energy may extend the facility up to an additional two years and may increase the aggregate amount of borrowings under the facility to $1.0 billion, both subject to lender participation. All borrowings under the facility are secured by KGE first mortgage bonds. As of December 31, 2011, $286.3 million had been borrowed and an additional $12.2 million of letters of credit had been issued under this revolving credit facility. As of December 31, 2010, $226.7 million had been borrowed and an additional $21.5 million of letters of credit had been issued under Westar Energy's previous $730.0 million revolving credit facility.

On February 18, 2011, Westar Energy entered into a revolving credit facility with a syndicate of banks for $270.0 million. The commitments under this facility terminate on February 18, 2015. As long as there is no default under the facility, Westar Energy may extend the facility up to an additional two years and may increase the aggregate amount of borrowings under the facility to $400.0 million, both subject to lender participation. All borrowings under the facility are secured by KGE first mortgage bonds. As of December 31, 2011, Westar Energy had no borrowed amounts or letters of credit outstanding under this revolving credit facility.

In addition, total combined borrowings under Westar Energy's commercial paper program and revolving credit facilities may not exceed $1.0 billion at any given time. The weighted average interest rate on short-term borrowings was 1.49% and 0.61% as of December 31, 2011 and 2010, respectively. Additional information regarding our short-term debt is as follows.



	As of December 31,
	2011			2010
	(Dollars in Thousands)

Weighted average short-term debt outstanding during the year	$	362,946		$	213,041
Weighted daily average interest rates during the year, excluding fees	0.82		%	0.63		%

Our interest expense on short-term debt was $3.9 million in 2011, $1.9 million in 2010 and $2.2 million in 2009.

Long-term Debt, Unclassified [Abstract]

The entire disclosure for short-term debt.

+ References+ Details

Long-Term Debt

12 Months Ended

Dec. 31, 2011

Long-term Debt

LONG-TERM DEBT

Outstanding Debt

The following table summarizes our long-term debt outstanding.



	As of December 31,
	2011			2010
	(In Thousands)
Westar Energy
First mortgage bond series:
6.00% due 2014	$	250,000		$	250,000
5.15% due 2017	125,000			125,000
5.95% due 2035	125,000			125,000
5.10% due 2020	250,000			250,000
5.875% due 2036	150,000			150,000
6.10% due 2047	150,000			150,000
8.625% due 2018	300,000			300,000
	1,350,000			1,350,000
Pollution control bond series:
Variable due 2032, 0.22% as of December 31, 2011; 0.60% as of December 31, 2010	45,000			45,000
Variable due 2032, 0.24% as of December 31, 2011; 0.54% as of December 31, 2010	30,500			30,500
5.00% due 2033	57,245			57,530
	132,745			133,030
Other long-term debt:
4.36% equipment financing loan due 2011	—			61

KGE
First mortgage bond series:
6.53% due 2037	175,000			175,000
6.15% due 2023	50,000			50,000
6.64% due 2038	100,000			100,000
6.70% due 2019	300,000			300,000
	625,000			625,000
Pollution control bond series:
5.10% due 2023	13,318			13,343
Variable due 2027, 0.28% as of December 31, 2011; 0.54% as of December 31, 2010	21,940			21,940
5.30% due 2031	108,600			108,600
5.30% due 2031	18,900			18,900
Variable due 2032, 0.28% as of December 31, 2011; 0.54% as of December 31, 2010	14,500			14,500
Variable due 2032, 0.28% as of December 31, 2011; 0.54% as of December 31, 2010	10,000			10,000
4.85% due 2031	50,000			50,000
5.60% due 2031	50,000			50,000
6.00% due 2031	50,000			50,000
5.00% due 2031	50,000			50,000
	387,258			387,283

Total long-term debt	2,495,003			2,495,374
Unamortized debt discount (a)	(3,894		)	(4,442		)
Long-term debt due within one year	—			(61		)
Long-term debt, net	$	2,491,109		$	2,490,871

Variable Interest Entities
7.77% due 2013 (b)	$	2,583		$	5,095
6.99% due 2014 (b)	2,094			3,237
5.92 % due 2019 (b)	22,748			31,171
5.647% due 2021 (b)	248,313			266,393
Total long-term debt of variable interest entities	275,738			305,896
Unamortized debt premium (a)	1,659			2,421
Long-term debt of variable interest entities due within one year	(28,114		)	(30,155		)
Long-term debt of variable interest entities, net	$	249,283		$	278,162

_______________

(a) We amortize debt discounts and premiums to interest expense over the term of the respective issues.

(b) Portions of our payments related to this debt reduce the principal balances each year until maturity.

The Westar Energy and KGE mortgages each contain provisions restricting the amount of first mortgage bonds that could be issued by each entity. We must comply with such restrictions prior to the issuance of additional first mortgage bonds or other secured indebtedness.

The amount of Westar Energy first mortgage bonds authorized by its Mortgage and Deed of Trust, dated July 1, 1939, as supplemented, is subject to certain limitations as described below. The amount of KGE first mortgage bonds authorized by the KGE Mortgage and Deed of Trust, dated April 1, 1940, as supplemented and amended, is limited to a maximum of $3.5 billion, unless amended further. First mortgage bonds are secured by utility assets. Amounts of additional bonds that may be issued are subject to property, earnings and certain restrictive provisions, except in connection with certain refundings, of each mortgage. As of December 31, 2011, approximately $1.0 billion principal amount of additional first mortgage bonds could be issued under the most restrictive provisions in Westar Energy's mortgage, except in connection with certain refundings. As of December 31, 2011, based on an assumed interest rate of 4.125%, approximately $436.2 million principal amount of additional KGE first mortgage bonds could be issued under the most restrictive provisions in KGE's mortgage.

As of December 31, 2011, we had $121.9 million of variable rate, tax-exempt bonds. Interest rates payable under these bonds had historically been set by auctions, which occur every 35 days. However, auctions for these bonds have failed over the past few years, resulting in volatile alternative index-based interest rates for these bonds. While the interest rates for these bonds have been extremely low, we continuously monitor the credit markets and evaluate our options with respect to our auction rate bonds.

On August 3, 2009, Westar Energy repaid $145.1 million principal amount of 7.125% unsecured senior notes with borrowings under Westar Energy's revolving credit facility.

On June 11, 2009, KGE issued $300.0 million principal amount of first mortgage bonds at a discount yielding 6.725%, bearing stated interest at 6.70% and maturing on June 15, 2019. KGE received net proceeds of $297.5 million.

Proceeds from the issuance of first mortgage bonds were used to repay borrowings under Westar Energy's revolving credit facility, with such borrowed amounts principally related to investments in capital equipment, as well as for working capital and general corporate purposes.

Debt Covenants

Some of our debt instruments contain restrictions that require us to maintain leverage ratios as defined in the credit agreements. We calculate these ratios in accordance with the agreements. We use these ratios solely to determine compliance with our various debt covenants. We were in compliance with these covenants as of December 31, 2011.

Maturities

The principal amounts of our long-term debt maturities as of December 31, 2011, are as follows.



Year	Long-term debt		Long-term debt of VIEs
	(In Thousands)
2012	$	—	$	28,114
2013	—		25,941
2014	250,000		27,479
2015	—		27,933
2016	—		28,309
Thereafter	2,245,003		137,962
Total maturities	$	2,495,003	$	275,738

Interest expense on long-term debt was $142.6 million in 2011, $144.1 million in 2010 and $139.6 million in 2009. Interest expense on long-term debt of VIEs was $16.8 million in 2011 and $18.7 million in 2010.

Taxes

12 Months Ended

Dec. 31, 2011

Income Tax Disclosure [Abstract]

Taxes

TAXES

Income tax expense is comprised of the following components.



	Year Ended December 31,
	2011			2010			2009
	(In Thousands)
Income Tax Expense (Benefit) from Continuing Operations:
Current income taxes:
Federal	$	(8,575	)	$	(32,107	)	$	2,428
State	196			(3,030		)	9,975
Deferred income taxes:
Federal	93,089			102,568			46,148
State	21,337			20,305			3,003
Investment tax credit amortization	(2,703		)	(2,704		)	(2,704		)
Income tax expense from continuing operations	$	103,344		$	85,032		$	58,850

Income Tax Expense (Benefit) from Discontinued Operations:
Current income taxes:
Federal	$	—		$	—		$	(25,528	)
State	—			—			(10,418		)
Deferred income taxes:
Federal	—			—			(20,549		)
Income tax expense from discontinued operations	$	—		$	—		$	(56,495	)

Total income tax expense	$	103,344		$	85,032		$	2,355

Deferred tax assets and liabilities are reflected on our consolidated balance sheets as follows.



	As of December 31,
	2011		2010
	(In Thousands)
Current deferred tax assets	$	394	$	30,248
Non-current deferred tax liabilities	1,110,463		1,102,625
Net deferred tax liabilities	$	1,110,069	$	1,072,377

The tax effect of the temporary differences and carryforwards that comprise our deferred tax assets and deferred tax liabilities are summarized in the following table.



	As of December 31,
	2011		2010
	(In Thousands)
Deferred tax assets:
Deferred employee benefit costs	$	202,687	$	155,400
Business tax credit carryforward (a)	159,163		134,629
Net operating loss carryforward (b)	84,365		—
Deferred regulatory gain on sale-leaseback	42,962		45,381
Deferred state income taxes	42,209		14,215
Alternative minimum tax carryforward (c)	36,471		34,270
Deferred compensation	28,286		40,401
Accrued liabilities	16,912		35,714
Disallowed costs	12,717		13,357
Capital loss carryforward (d)	12,554		3,527
Other	13,031		33,577
Total gross deferred tax assets	651,357		510,471
Less: Valuation allowance (e)	13,712		59,415
Deferred tax assets	$	637,645	$	451,056

Deferred tax liabilities:
Accelerated depreciation	$	1,088,727	$	920,229
Deferred employee benefit costs	202,687		161,035
Acquisition premium	187,934		195,947
Amounts due from customers for future income taxes, net	168,804		172,181
Deferred state income taxes	39,512		16,577
Debt reacquisition costs	21,683		23,864
Pension expense tracker	14,600		8,446
Storm costs	10,176		13,733
Other	13,591		11,421
Total deferred tax liabilities	$	1,747,714	$	1,523,433

Net deferred tax liabilities	$	1,110,069	$	1,072,377

_______________

(a)

Based on filed tax returns and amounts expected to be reported in current year tax returns (December 31, 2011), we had available federal general business tax credits of $29.7 million and state investment tax credits of $129.5 million. The federal general business tax credits were primarily generated from affordable housing partnerships in which we sold the majority of our interests in 2001. These tax credits expire beginning in 2020 and ending in 2031. The state investment tax credits expire beginning in 2013 and ending in 2027. We believe these tax credits will be fully utilized prior to expiration.


(b)	As of December 31, 2011, we had a federal net operating loss carryforward of $206.6 million, which is available to offset federal taxable income. The net operating losses will expire in 2030 and 2031.


(c)	As of December 31, 2011, we had available an alternative minimum tax credit carryforward of $36.5 million, which has an unlimited carryforward period.


(d)	As of December 31, 2011, we had an unused capital loss carryforward of $31.7 million that is available to offset future capital gains. The capital losses will expire beginning in 2013 and ending in 2016.

(e)

As we do not expect to realize any significant capital gains in the future, we have established a valuation allowance of $12.5 million. In addition, we have established a valuation allowance of $1.2 million for certain deferred tax assets related to the write-down of other investments. The total valuation allowance related to the deferred tax assets was $13.7 million as of December 31, 2011, and $59.4 million as of December 31, 2010. The valuation allowance decreased $45.7 million in 2011 due to the reversal of a valuation allowance of $51.9 million that we had established against unused state investment tax credits. We reversed this valuation allowance because the state investment tax credits are now more likely than not to be realized due to a state law change which extended the state tax credit carryforward period from 10 to 16 years.

In accordance with various orders, we have reduced our prices to reflect the income tax benefits associated with certain accelerated income tax deductions. We believe it is probable that the net future increases in income taxes payable will be recovered from customers when these temporary income tax benefits reverse. We have recorded a regulatory asset for these amounts. We also have recorded a regulatory liability for our obligation to reduce the prices charged to customers for deferred income taxes recovered from customers at corporate income tax rates higher than current income tax rates. The price reduction will occur as the temporary differences resulting in the excess deferred income tax liabilities reverse. The income tax-related regulatory assets and liabilities as well as unamortized investment tax credits are also temporary differences for which deferred income taxes have been provided. The net deferred income tax liability related to these temporary differences is classified above as amounts due from customers for future income taxes, net.

Our effective income tax rates are computed by dividing total federal and state income taxes by the sum of such taxes and net income. The difference between the effective income tax rates and the federal statutory income tax rates are as follows.



	For the Year Ended December 31,
	2011		2010		2009
Statutory federal income tax rate from continuing operations	35.0	%	35.0	%	35.0	%
Effect of:
Corporate-owned life insurance policies	(4.5	)	(6.1	)	(8.2	)
State income taxes	4.1		3.8		4.3
Production tax credits	(2.9	)	(3.4	)	(3.0	)
Accelerated depreciation flow through and amortization	1.8		2.6		3.7
Amortization of federal investment tax credits	(0.8	)	(0.9	)	(1.4	)
AFUDC equity	(0.6	)	(0.4	)	(0.9	)
Capital loss utilization	(0.5	)	(0.7	)	(0.4	)
Liability for unrecognized income tax benefits	—		(0.2	)	0.2
Other	(1.2	)	(0.7	)	0.1
Effective income tax rate from continuing operations	30.4	%	29.0	%	29.4	%

We file income tax returns in the U.S. federal jurisdiction as well as various state and foreign jurisdictions. The income tax returns we file will likely be audited by the Internal Revenue Service (IRS) or other tax authorities. With few exceptions, the statute of limitations with respect to U.S. federal, state and local, or non-U.S. income tax examinations by tax authorities remains open for tax year 2008 and forward.

In the first and second quarters of 2011, the IRS completed its separate examinations of our federal income tax returns filed for tax years 2008 and 2009, respectively, without significant changes.

In November 2009, the IRS completed its examination of the federal income tax return and the amended federal income tax returns we filed for tax years 1999, 2005, 2006 and 2007. The examination resulted in a tax refund of $34.9 million. The examination results were approved by the Joint Committee on Taxation of the U.S. Congress and accepted by the IRS in April 2010.

In January 2009, we reached a settlement with the IRS for tax years 2003 and 2004 that included a determination of the amount of the net capital loss and net operating loss carryforwards available from the sale of a former subsidiary in 2004. This settlement resulted in our recording in 2009 a net earnings benefit from discontinued operations of approximately $33.7 million, net of $22.8 million paid to the former subsidiary under the sale agreement.

The liability for unrecognized income tax benefits increased from $1.9 million at December 31, 2010, to $2.5 million at December 31, 2011. The net increase in the liability for unrecognized income tax benefits was largely attributable to tax positions taken with respect to the capitalization of plant related expenditures. We do not expect significant changes in the liability for unrecognized income tax benefits in the next 12 months. A reconciliation of the beginning and ending amounts of unrecognized income tax benefits is as follows:



	2011			2010			2009
	(In Thousands)
Liability for unrecognized income tax benefits as of January 1	$	1,888		$	8,357		$	38,980
Additions based on tax positions related to the current year	967			608			2,254
Additions for tax positions of prior years	939			2,323			—
Reductions for tax positions of prior years	(563		)	(1,241		)	(25,722		)
Settlements	(748		)	(8,159		)	(7,155		)
Liability for unrecognized income tax benefits as of December 31	$	2,483		$	1,888		$	8,357

The liability for unrecognized income tax benefits, as disclosed above, is net of reductions to deferred tax assets for tax loss and credit carryforwards of $0.2 million, $1.0 million and $23.7 million as of December 31, 2011, 2010, 2009, respectively. The amounts of unrecognized income tax benefits that, if recognized, would favorably impact our effective income tax rate, were $1.2 million, $1.3 million and $2.1 million (net of tax) as of December 31, 2011, 2010 and 2009, respectively.

Interest related to income tax uncertainties is classified as interest expense and accrued interest liability. During 2011, 2010 and 2009, we reversed interest expense previously recorded for income tax uncertainties of $0.2 million, $1.0 million and $2.4 million, respectively. As of December 31, 2011 and 2010, we had $0.2 million and $0.4 million, respectively, accrued for interest on our liability related to unrecognized income tax benefits. We accrued no penalties at either December 31, 2011, or December 31, 2010.

As of December 31, 2011 and 2010, we had recorded $1.5 million and $3.6 million, respectively, for probable assessments of taxes other than income taxes.

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

Compensation and Retirement Disclosure [Abstract]

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 08

-Paragraph h

-Article 4

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 109

-Paragraph 136, 172

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 109

-Paragraph 43, 44, 45, 46, 47, 48, 49

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 15

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32718-109319

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 9

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32639-109319

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(h))

-URI http://asc.fasb.org/extlink&oid=6881521&loc=d3e23780-122690

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32537-109319

Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 740

-SubTopic 10

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6907707&loc=d3e32559-109319

+ Details

Employee Benefit Plans

12 Months Ended

Dec. 31, 2011

Interim Pension And Post-Retirement Benefit Disclosure

EMPLOYEE BENEFIT PLANS

Pension and Post-Retirement Benefit Plans

We maintain a qualified non-contributory defined benefit pension plan covering substantially all of our employees. For the majority of our employees, pension benefits are based on years of service and an employee's compensation during the 60 highest paid consecutive months out of 120 before retirement. Non-union employees hired after December 31, 2001, and union employees hired after December 31, 2011, are covered by the same defined benefit pension plan; however, their benefits are derived from a cash balance account formula. We also maintain a non-qualified Executive Salary Continuation Plan for the benefit of certain current and retired executive officers. With the exception of one current executive officer, we have discontinued accruing any future benefits under this non-qualified plan.

We expect to fund our pension plan each year at least to a level equal to our current year pension expense. We must also meet minimum funding requirements under the Employee Retirement Income Security Act, as amended by the Pension Protection Act. We may contribute additional amounts from time to time as deemed appropriate.

In addition to providing pension benefits, we provide certain post-retirement health care and life insurance benefits for substantially all retired employees. We accrue and recover in our prices the costs of post-retirement benefits during an employee's years of service. We fund the portion of net periodic costs for post-retirement benefits included in our prices.

As a co-owner of Wolf Creek, KGE is indirectly responsible for 47% of the liabilities and expenses associated with the Wolf Creek pension and post-retirement benefit plans. See Note 12, "Wolf Creek Employee Benefit Plans," for information about Wolf Creek's benefit plans.

The following tables summarize the status of our pension and post-retirement benefit plans.



	Pension Benefits						Post-retirement Benefits
As of December 31,	2011			2010			2011			2010
	(In Thousands)
Change in Benefit Obligation:
Benefit obligation, beginning of year	$	747,460		$	662,495		$	137,759		$	128,998
Service cost	16,076			13,926			1,803			1,526
Interest cost	40,045			39,391			6,793			7,083
Plan participants’ contributions	—			—			3,390			3,292
Benefits paid	(31,107		)	(29,690		)	(10,114		)	(11,090		)
Actuarial losses (gains)	94,161			60,662			5,246			7,950
Amendments	—			676			4,451			—
Other (a)	9,673			—			750			—
Benefit obligation, end of year	$	876,308		$	747,460		$	150,078		$	137,759

Change in Plan Assets:
Fair value of plan assets, beginning of year	$	432,233		$	404,243		$	86,984		$	74,114
Actual return on plan assets	27,819			33,359			(174		)	9,849
Employer contributions	50,000			22,400			10,793			10,512
Plan participants’ contributions	—			—			3,244			3,147
Part D reimbursements	—			—			—			317
Benefits paid	(28,975		)	(27,769		)	(9,739		)	(10,955		)
Other (a)	—			—			750			—
Fair value of plan assets, end of year	$	481,077		$	432,233		$	91,858		$	86,984

Funded status, end of year	$	(395,231	)	$	(315,227	)	$	(58,220	)	$	(50,775	)

Amounts Recognized in the Balance Sheets Consist of:
Current liability	$	(2,741	)	$	(2,030	)	$	(115	)	$	(91	)
Noncurrent liability	(392,490		)	(313,197		)	(58,105		)	(50,684		)
Net amount recognized	$	(395,231	)	$	(315,227	)	$	(58,220	)	$	(50,775	)

Amounts Recognized in Regulatory Assets Consist of:
Net actuarial loss	$	397,691		$	323,924		$	18,178		$	8,458
Prior service cost	4,606			5,819			18,991			17,065
Transition obligation	—			—			4,236			8,148
Net amount recognized	$	402,297		$	329,743		$	41,405		$	33,671

_______________


(a)	Other includes the $9.7 million reclassification of a contractual obligation related to the legal settlement with a former executive officer and $0.8 million of proceeds received as a result of the Early Retiree Reinsurance Program.



	Pension Benefits						Post-retirement Benefits
As of December 31,	2011			2010			2011			2010
	(Dollars in Thousands)
Pension Plans With a Projected Benefit Obligation In Excess of Plan Assets:
Projected benefit obligation	$	876,308		$	747,460		$	—		$	—
Fair value of plan assets	481,077			432,233			—			—

Pension Plans With an Accumulated Benefit Obligation In Excess of Plan Assets:
Accumulated benefit obligation	$	750,263		$	635,541		—			—
Fair value of plan assets	481,077			432,233			—			—

Post-retirement Plans With an Accumulated Post-retirement Benefit Obligation In Excess of Plan Assets:
Accumulated post-retirement benefit obligation	—			—			$	150,078		$	137,759
Fair value of plan assets	—			—			91,858			86,984

Weighted-Average Actuarial Assumptions used to Determine Net Periodic Benefit Obligation:
Discount rate	4.50		%	5.35		%	4.25		%	5.00		%
Compensation rate increase	4.00		%	4.00		%	—			—

We use a measurement date of December 31 for our pension and post-retirement benefit plans. In addition, we use an interest rate yield curve that is constructed based on the yields of over 500 high-quality, non-callable corporate bonds with maturities between zero and 30 years. A theoretical spot rate curve constructed from this yield curve is then used to discount the annual benefit cash flows of our pension plan and develop a single-point discount rate matching the plan's payout structure.

We amortize prior service cost (benefit) on a straight-line basis over the average future service of the active employees (plan participants) benefiting under the plan at the time of the amendment. We amortize the net actuarial gain or loss on a straight-line basis over the average future service of active plan participants benefiting under the plan without application of an amortization corridor. Following is additional information regarding our pension and post-retirement benefit plans.



	Pension Benefits									Post-retirement Benefits
Year Ended December 31,	2011			2010			2009			2011			2010			2009
	(Dollars in Thousands)
Components of Net Periodic Cost (Benefit):
Service cost	$	16,076		$	13,926		$	12,882		$	1,803		$	1,526		$	1,529
Interest cost	40,045			39,391			38,162			6,793			7,083			6,917
Expected return on plan assets	(31,087		)	(38,384		)	(37,826		)	(5,002		)	(5,197		)	(4,756		)
Amortization of unrecognized:
Transition obligation, net	—			—			—			3,911			3,912			3,912
Prior service costs	1,213			2,729			2,668			2,524			2,154			1,580
Actuarial loss/(gain), net	23,659			17,183			14,263			702			321			(38		)
Net periodic cost before regulatory adjustment	49,906			34,845			30,149			10,731			9,799			9,144
Regulatory adjustment	(22,098		)	(12,167		)	(9,188		)	1,344			1,868			2,280
Net periodic cost	$	27,808		$	22,678		$	20,961		$	12,075		$	11,667		$	11,424

Other Changes in Plan Assets and Benefit Obligations Recognized in Regulatory Assets:
Current year actuarial (gain)/loss	$	97,429		$	65,690		$	(34,610	)	$	10,421		$	3,298		$	(26,205	)
Amortization of actuarial (loss)/gain	(23,659		)	(17,183		)	(14,263		)	(702		)	(321		)	38
Current year prior service cost	—			676			48			4,451			—			6,672
Amortization of prior service costs	(1,213		)	(2,729		)	(2,668		)	(2,524		)	(2,154		)	(1,580		)
Current year offset of initial transition asset due to plan change	—			—			—			—			—			(76		)
Amortization of transition obligation	—			—			—			(3,911		)	(3,912		)	(3,912		)
Total recognized in regulatory assets	$	72,557		$	46,454		$	(51,493	)	$	7,735		$	(3,089	)	$	(25,063	)

Total recognized in net periodic cost and regulatory assets	$	100,365		$	69,132		$	(30,532	)	$	19,810		$	8,578		$	(13,639	)

Weighted-Average Actuarial Assumptions used to Determine Net Periodic Cost (Benefit):
Discount rate	5.35		%	5.95		%	6.10		%	5.00		%	5.65		%	6.05		%
Expected long-term return on plan assets	6.50		%	8.25		%	8.25		%	6.00		%	7.75		%	7.75		%
Compensation rate increase	4.00		%	4.00		%	4.00		%	—			—			—

We estimate that we will amortize the following amounts from regulatory assets into net periodic cost in 2012.



	Pension Benefits		Post-retirement Benefits
	(In Thousands)

Actuarial loss	$	32,782	$	1,509
Prior service cost	613		2,524
Transition obligation	—		3,911
Total	$	33,395	$	7,944

We base the expected long-term rate of return on plan assets on historical and projected rates of return for current and planned asset classes in the plans' investment portfolios. We select assumed projected rates of return for each asset class after analyzing long-term historical experience and future expectations of the volatility of the various asset classes. Based on target asset allocations for each asset class, we develop an overall expected rate of return for the portfolios, adjusted for historical and expected experience of active portfolio management results compared to benchmark returns and for the effect of expenses paid from plan assets.

The Medicare Prescription Drug Improvement and Modernization Act of 2003 introduced a prescription drug benefit under Medicare as well as a federal subsidy that will be paid to sponsors of retiree health care benefit plans that provide a benefit that is at least actuarially equivalent to Medicare. Prior to January 1, 2010, we believed that our retiree health care benefit plan was at least actuarially equivalent to Medicare and was, thus, eligible for the federal subsidy. However, due to plan changes effective January 1, 2010, we are no longer entitled to the federal subsidy. As a result, the subsidy did not have an effect on our accumulated post-retirement benefit obligation in 2011, 2010 or 2009, and did not impact our net period post-retirement benefit cost in 2011 or 2010. The subsidy decreased net periodic post-retirement benefit cost by approximately $1.9 million in 2009.

For measurement purposes, the assumed annual health care cost growth rates were as follows.



	As of December 31,
	2011	2010

Health care cost trend rate assumed for next year	8.0%	8.0%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate)	5.0%	5.0%

Year that the rate reaches the ultimate trend rate	2018	2018

The health care cost trend rate affects the projected benefit obligation. A 1% change in assumed health care cost growth rates would have effects shown in the following table.



	One-Percentage- Point Increase		One-Percentage- Point Decrease
	(In Thousands)

Effect on total of service and interest cost	$	69	$	(65	)
Effect on post-retirement benefit obligation	1,465		(1,362		)

Plan Assets

We manage pension and post-retirement benefit plan assets in a prudent manner with regard to preserving principal while providing reasonable returns. We have adopted a long-term investment horizon such that the chances and duration of investment losses are carefully weighed against the long-term potential for appreciation of assets. Part of our strategy includes managing interest rate sensitivity of plan assets relative to the associated liabilities. The primary objective of the pension plan is to provide a source of retirement income for its participants and beneficiaries, and the primary financial objective of the plan is to improve its funded status. The primary objective of the post-retirement benefit plan is growth in assets and preservation of principal, while minimizing interim volatility, to meet anticipated claims of plan participants. We delegate the management of our pension and post-retirement benefit plan assets to independent investment advisors who hire and dismiss investment managers based upon various factors. The investment advisors strive to diversify investments across asset classes, sectors and manager styles to minimize the risk of large losses, based upon objectives and risk tolerance specified by management, which include allowable and/or prohibited investment types. We measure and monitor investment risk on an ongoing basis through quarterly investment portfolio reviews and annual liability measurements.

As noted above, we have established certain prohibited investments for our pension and post-retirement benefit plans. Such prohibited investments include loans to the company or its officers and directors as well as investments in the company's debt or equity securities, except as may occur indirectly through investments in diversified mutual funds. In addition, we have established restrictions to reduce concentration of risk. For example, for domestic investments, no more than 5% of pension plan assets and 5% of post-retirement benefit plan assets should be invested in the securities of a single issuer, with the exception of the U.S. government and its agencies. In addition, the plans will neither acquire more than 10% of any one issuer nor invest more than 25% of their assets in any single industry. These restrictions do not apply to securities issued or guaranteed by the U.S. government or its agencies.

The target allocations for our pension plan assets are about 42% to equity securities, 44% to debt securities and the remaining 14% to other investments such as real estate securities, hedge funds and private equity investments. Our investments in equity include investment funds with underlying investments in domestic and foreign large-, mid- and small-cap companies, derivatives related to such holdings, private equity investments including, late-state venture investments and other investments. Our investments in debt include core and high-yield bonds. Core bonds are comprised of investment funds with underlying investments in investment grade debt securities of corporate entities, obligations of U.S. and foreign governments and their agencies, and other debt securities. High-yield bonds include investment funds with underlying investments in non-investment grade debt securities of corporate entities, obligations of foreign governments and their agencies, private debt securities and other debt securities. Real estate securities consist primarily of funds invested in core real estate throughout the U.S. while alternative funds invest in wide ranging investments including equity and debt securities of domestic and foreign corporations , debt securities issued by U.S. and foreign governments and their agencies, structured debt, warrants, exchange-traded funds, derivative instruments, private investment funds and other investments.

The target allocations for our post-retirement benefit plan assets are 65% to equity securities and 35% to debt securities. Our investments in equity securities include investment funds with underlying investments primarily in domestic and foreign large-, mid- and small-cap companies. Our investments in debt securities include a core bond fund with underlying investments in investment grade debt securities of domestic and foreign corporate entities, obligations of U.S. and foreign governments and their agencies, private placement securities and other investments.

Similar to other assets measured at fair value, GAAP establishes a hierarchal framework for disclosing the transparency of the inputs utilized in measuring pension and post-retirement benefit plan assets at fair value. From time to time, the pension and post-retirement benefits trusts may buy and sell investments resulting in changes within the hierarchy. See Note 4, "Financial and Derivative Instruments, Trading Securities, Energy Marketing and Risk Management," for a description of the hierarchal framework.

All level 2 pension investments are held in investment funds that are measured at fair value using daily net asset values as reported by the trustee, except for $14.1 million as of December 31, 2011, invested directly in long-term U.S. Treasury securities. We also maintain certain level 3 investments in private equity, high-yield bonds, real estate securities and alternative funds that require significant unobservable market information to measure the fair value of the investments. The fair value of private equity investments is measured by utilizing both market- and income-based models, public company comparables, at cost or at the value derived from subsequent financings. Adjustments are made when actual performance differs from expected performance; when market, economic or company-specific conditions change; and when other news or events have a material impact on the security. To measure the fair value of real estate securities we use a combination of market- and income-based models utilizing market discount rates, projected cash flows and the estimated value into perpetuity. Alternative funds are measured at fair value using net asset values as reported by the alternative fund managers. Since the underlying assets in alternative funds vary widely various methods are required, often utilizing significant management judgment.

The following table provides the fair value of our pension plan assets and the corresponding level of hierarchy as of December 31, 2011 and 2010.



As of December 31, 2011	Level 1		Level 2		Level 3		Total
	(In Thousands)
Assets:
Domestic equity	$	—	$	121,364	$	15,375	$	136,739
International equity	—		53,943		—		53,943
Core bonds	—		142,700		—		142,700
High-yield bonds	—		38,380		—		38,380
Combination debt/equity fund	—		47,151		—		47,151
Real estate securities	—		—		18,848		18,848
Alternative funds	—		—		40,716		40,716
Cash equivalents	—		2,600		—		2,600
Total Assets Measured at Fair Value	$	—	$	406,138	$	74,939	$	481,077

As of December 31, 2010

Assets:
Domestic equity	$	—	$	117,250	$	11,575	$	128,825
International equity	—		44,834		—		44,834
Core bonds	—		183,361		—		183,361
High-yield bonds	—		28,819		1,200		30,019
Real estate securities	—		—		16,411		16,411
Alternative funds	—		—		25,764		25,764
Cash equivalents	—		3,019		—		3,019
Total Assets Measured at Fair Value	$	—	$	377,283	$	54,950	$	432,233

The following table provides a reconciliation of pension plan assets measured at fair value using significant level 3 inputs for the years ended December 31, 2011 and 2010.



	Domestic Equity		High-yield Bonds			Real Estate Securities			Alternative Funds			Net Balance
	(In Thousands)

Balance as of December 31, 2010	$	11,575	$	1,200		$	16,411		$	25,764		$	54,950
Actual gain (loss) on plan assets:
Relating to assets still held at the reporting date	1,910		—			2,652			(48		)	4,514
Relating to assets sold during the period	—		—			(49		)	—			(49		)
Purchases, issuances and settlements, net	1,890		(1,200		)	(166		)	15,000			15,524
Balance as of December 31, 2011	$	15,375	$	—		$	18,848		$	40,716		$	74,939

Balance as of December 31, 2009	$	9,310	$	22,519		$	14,518		$	—		$	46,347
Actual gain (loss) on plan assets:
Relating to assets still held at the reporting date	75		(3,963		)	2,117			864			(907		)
Relating to assets sold during the period	—		4,325			(77		)	—			4,248
Purchases, issuances and settlements, net	2,190		(21,681		)	(147		)	24,900			5,262
Balance as of December 31, 2010	$	11,575	$	1,200		$	16,411		$	25,764		$	54,950

The following table provides the fair value of our post-retirement benefit plan assets and the corresponding level of hierarchy as of December 31, 2011 and 2010.



As of December 31, 2011	Level 1		Level 2		Level 3		Total
	(In Thousands)
Assets:
Domestic equity	$	—	$	47,411	$	—	$	47,411
International equity	—		11,500		—		11,500
Core bonds	—		32,192		—		32,192
Cash equivalents	—		755		—		755
Total Assets Measured at Fair Value	$	—	$	91,858	$	—	$	91,858

As of December 31, 2010

Assets:
Domestic equity	$	—	$	45,766	$	—	$	45,766
International equity	—		11,280		—		11,280
Core bonds	—		29,938		—		29,938
Total Assets Measured at Fair Value	$	—	$	86,984	$	—	$	86,984

Cash Flows

The following table shows the expected cash flows for our pension and post-retirement benefit plans for future years.



Expected Cash Flows	Pension Benefits						Post-retirement Benefits
	To/(From) Trust			To/(From) Company Assets			To/(From) Trust			To/(From) Company Assets
	(In Millions)
Expected contributions:
2012	$	57.4		$	2.7		$	10.8		$	0.1

Expected benefit payments:
2012	$	(29.3	)	$	(2.7	)	$	(7.9	)	$	(0.1	)
2013	(31.1		)	(2.7		)	(8.3		)	(0.1		)
2014	(33.1		)	(2.8		)	(8.7		)	(0.1		)
2015	(35.1		)	(2.8		)	(9.3		)	(0.1		)
2016	(37.8		)	(2.8		)	(9.6		)	(0.1		)
2017 - 2021	(231.9		)	(13.2		)	(51.3		)	(0.7		)

Savings Plans

We maintain a qualified 401(k) savings plan in which most of our employees participate. We match employees' contributions in cash up to specified maximum limits. Our contributions to the plans are deposited with a trustee and invested at the direction of plan participants into one or more of the investment alternatives we provide under the plan. Our contributions totaled $7.0 million in 2011, $7.4 million in 2010 and $6.5 million in 2009.

Stock-Based Compensation Plans

We have a long-term incentive and share award plan (LTISA Plan), which is a stock-based compensation plan in which employees and directors are eligible for awards. The LTISA Plan was implemented as a means to attract, retain and motivate employees and directors. Under the LTISA Plan, we may grant awards in the form of stock options, dividend equivalents, share appreciation rights, RSUs, performance shares and performance share units to plan participants. On May 19, 2011, Westar Energy shareholders approved an increase in the number of shares of common stock that may be granted under the LTISA Plan to 8.25 million shares from 5.0 million shares. As of December 31, 2011, awards of approximately 4.5 million shares of common stock had been made under the plan.

All stock-based compensation is measured at the grant date based on the fair value of the award and is recognized as an expense in the consolidated statement of income over the requisite service period. The requisite service periods range from one to ten years. The table below shows compensation expense and income tax benefits related to stock-based compensation arrangements that are included in our net income.



	Year Ended December 31,
	2011		2010		2009
	(In Thousands)

Compensation expense	$	8,367	$	11,321	$	5,080
Income tax benefits related to stock-based compensation arrangements	3,309		4,481		2,011

We use RSU awards for our stock-based compensation awards. RSU awards are grants that entitle the holder to receive shares of common stock as the awards vest. These RSU awards are defined as nonvested shares and do not include restrictions once the awards have vested. In 2011, outstanding RSUs with only service requirements previously awarded to our chief executive officer that were subject to forfeiture were modified to provide for the vesting upon his retirement on July 31, 2011, of a prorated number of the RSUs based on the number of days from the grant date of the RSUs to his retirement date. In addition, outstanding RSUs with performance measures previously awarded to our chief executive officer were modified to provide for the vesting on the scheduled vesting date, subject to the satisfaction of the applicable performance criteria, of a prorated number of the target RSUs based on the number of days from the grant date of the RSUs to his retirement date. We recorded compensation expense of $2.8 million related to these modifications.

RSU awards with only service requirements vest solely upon the passage of time. We measure the fair value of these RSU awards based on the market price of the underlying common stock as of the grant date. RSU awards with only service conditions that have a graded vesting schedule are recognized as an expense in the consolidated statement of income on a straight-line basis over the requisite service period for the entire award. Nonforfeitable dividend equivalents, or the rights to receive cash equal to the value of dividends paid on Westar Energy's common stock, are paid on these RSUs during the vesting period.

RSU awards with performance measures vest upon expiration of the award term. The number of shares of common stock awarded upon vesting will vary from 0% to 200% of the RSU award, with performance tied to our total shareholder return relative to the total shareholder return of our peer group. We measure the fair value of these RSU awards using a Monte Carlo simulation technique that uses the closing stock price at the valuation date and incorporates assumptions for inputs of the expected volatility and risk-free interest rates. Expected volatility is based on historical volatility over three years using daily stock price observations. The risk-free interest rate is based on treasury constant maturity yields as reported by the Federal Reserve and the length of the performance period. For the 2011 valuation, inputs for expected volatility and risk-free interest rates ranged from 24.5% to 28.5% and 0.1% to 1.3%, respectively. For the 2010 valuation, inputs for expected volatility and risk-free interest rates ranged from 25.2% to 30.1% and 0.3% to 1.4%, respectively. For these RSU awards, dividend equivalents accumulate over the vesting period and are paid in cash based on the number of shares of common stock awarded upon vesting.

During the years ended December 31, 2011, 2010 and 2009, our RSU activity for awards with only service requirements was as follows:



	As of December 31,
	2011				2010				2009
	Shares		Weighted- Average Grant Date Fair Value		Shares		Weighted- Average Grant Date Fair Value		Shares		Weighted- Average Grant Date Fair Value
	(Shares In Thousands)

Nonvested balance, beginning of year	600.4		$	21.50	368.8		$	21.98	727.4		$	20.86
Granted	284.1		26.30		366.4		22.14		83.5		18.33
Vested	(187.3	)	23.50		(118.1	)	24.81		(439.0	)	19.43
Forfeited	(328.7	)	24.37		(16.7	)	22.32		(3.1	)	20.63
Nonvested balance, end of year	368.5		23.83		600.4		21.50		368.8		21.98

Total unrecognized compensation cost related to RSU awards with only service requirements was $4.2 million as of December 31, 2011. We expect to recognize these costs over a remaining weighted-average period of 1.9 years. The total fair value of RSUs with only service requirements that vested during the years ended December 31, 2011, 2010 and 2009, was $4.8 million, $2.7 million and $8.8 million, respectively.

During the years ended December 31, 2011, 2010 and 2009, our RSU activity for awards with performance measures was as follows:



	As of December 31,
	2011				2010				2009
	Shares		Weighted- Average Grant Date Fair Value		Shares		Weighted- Average Grant Date Fair Value		Shares	Weighted- Average Grant Date Fair Value
	(Shares In Thousands)

Nonvested balance, beginning of year	348.4		$	24.98	—		$	—	—	$	—
Granted	244.4		31.26		366.0		24.96		—	—
Vested	(119.5	)	24.12		(4.5	)	23.32		—	—
Forfeited	(149.1	)	28.72		(13.1	)	24.99		—	—
Nonvested balance, end of year	324.2		28.31		348.4		24.98		—	—

Total unrecognized compensation cost related to RSU awards with performance measures was $3.3 million as of December 31, 2011. We expect to recognize these costs over a remaining weighted-average period of 1.7 years. The total fair value of RSUs with performance measures that vested during the year ended December 31, 2011 was $3.6 million. No performance RSUs vested in 2010 and 2009.

Previously, RSU awards that could be settled in cash upon a change in control were classified as temporary equity. However, all of these awards were forfeited in 2011. As of December 31, 2010, we had temporary equity of $3.5 million recorded on our consolidated balance sheet.

Stock options granted between 1998 and 2001 are completely vested and have expired. There were no options exercised and all remaining options were forfeited during the year ended December 31, 2010. We currently have no plans to issue new stock option awards.

Another component of the LTISA Plan is the Executive Stock for Compensation program under which, in the past, eligible employees were entitled to receive deferred common stock in lieu of current cash compensation. Although this plan was discontinued in 2001, dividends will continue to be paid to plan participants on their outstanding plan balance until distribution. Plan participants were awarded 4,757 shares of common stock for dividends in 2011, 6,627 shares in 2010 and 7,106 shares in 2009. Participants received common stock distributions of 67,426 shares in 2011, 1,198 shares in 2010 and 563 shares in 2009.

Income tax benefits resulting from the income tax deductions in excess of the related compensation cost recognized in the financial statements is classified as cash flows from financing activities in the consolidated statements of cash flows.

The entire disclosure for pension and other postretirement benefits.

Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]

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+ Details

Wolf Creek Employee Benefit Plans

12 Months Ended

Dec. 31, 2011

Wolf Creek Interim Pension And Post-Retirement Benefit Disclosure

WOLF CREEK EMPLOYEE BENEFIT PLANS

Pension and Post-retirement Benefit Plans

As a co-owner of Wolf Creek, KGE is indirectly responsible for 47% of the liabilities and expenses associated with the Wolf Creek pension and post-retirement benefit plans. KGE accrues its 47% share of Wolf Creek's cost of pension and post-retirement benefits during the years an employee provides service. The following tables summarize the status of KGE's 47% share of the Wolf Creek pension and post-retirement benefit plans.



	Pension Benefits						Post-retirement Benefits
As of December 31,	2011			2010			2011			2010
	(In Thousands)
Change in Benefit Obligation:
Benefit obligation, beginning of year	$	131,460		$	111,033		$	10,144		$	9,574
Service cost	4,957			4,144			165			179
Interest cost	7,370			6,941			458			519
Plan participants’ contributions	—			—			614			554
Benefits paid	(3,033		)	(2,799		)	(979		)	(1,045		)
Actuarial losses (gains)	20,642			12,141			(360		)	363
Other (a)	—			—			87			—
Benefit obligation, end of year	$	161,396		$	131,460		$	10,129		$	10,144

Change in Plan Assets:
Fair value of plan assets, beginning of year	$	76,086		$	62,516		$	—		$	—
Actual return on plan assets	(2,578		)	10,082			—			—
Employer contributions	10,009			6,044			369			—
Plan participants' contribution	—			—			614			—
Benefits paid	(2,790		)	(2,556		)	(979		)	—
Fair value of plan assets, end of year	$	80,727		$	76,086		$	4		$	—

Funded status, end of year	$	(80,669	)	$	(55,374	)	$	(10,125	)	$	(10,144	)

Amounts Recognized in the Balance Sheets Consist of:
Current liability	$	(243	)	$	(256	)	$	(609	)	$	(689	)
Noncurrent liability	(80,426		)	(55,118		)	(9,516		)	(9,455		)
Net amount recognized	$	(80,669	)	$	(55,374	)	$	(10,125	)	$	(10,144	)

Amounts Recognized in Regulatory Assets Consist of:
Net actuarial loss	$	65,273		$	39,735		$	3,208		$	3,796
Prior service cost	31			47			—			—
Transition obligation	—			52			58			115
Net amount recognized	$	65,304		$	39,834		$	3,266		$	3,911

	Pension Benefits						Post-retirement Benefits
As of December 31,	2011			2010			2011			2010
	(Dollars in Thousands)
Pension Plans With a Projected Benefit Obligation In Excess of Plan Assets:
Projected benefit obligation	$	161,396		$	131,460		$	—		$	—
Fair value of plan assets	80,727			76,086			—			—

Pension Plans With an Accumulated Benefit Obligation In Excess of Plan Assets:
Accumulated benefit obligation	$	128,633		$	106,684		$	—		$	—
Fair value of plan assets	80,727			76,086			—			—

Post-retirement Plans With an Accumulated Post-retirement Benefit Obligation In Excess of Plan Assets:
Accumulated post-retirement benefit obligation	$	—		$	—		$	10,129		$	10,144
Fair value of plan assets	—			—			4			—

Weighted-Average Actuarial Assumptions used to Determine Net Periodic Benefit Obligation:
Discount rate	4.55		%	5.45		%	4.10		%	4.90		%
Compensation rate increase	4.00		%	4.00		%	—			—

_______________


(a)	Includes proceeds received as a result of the Early Retiree Reinsurance Program.

Wolf Creek uses a measurement date of December 31 for its pension and post-retirement benefit plans. In addition, Wolf Creek uses an interest rate yield curve that is constructed based on the yields on over 500 high-quality, non-callable corporate bonds with maturities between zero and 30 years. A theoretical spot rate curve constructed from this yield curve is then used to discount the annual benefit cash flows of Wolf Creek's pension plan and develop a single-point discount rate matching the plan's payout structure.

The prior service cost (benefit) is amortized on a straight-line basis over the average future service of the active employees (plan participants) benefiting under the plan at the time of the amendment. The net actuarial gain or loss is amortized on a straight-line basis over the average future service of active plan participants benefiting under the plan without application of an amortization corridor. Following is additional information regarding KGE's 47% share of the Wolf Creek pension and other post-retirement benefit plans.



	Pension Benefits									Post-retirement Benefits
Year Ended December 31,	2011			2010			2009			2011			2010			2009
	(Dollars in Thousands)
Components of Net Periodic Cost (Benefit):
Service cost	$	4,957		$	4,144		$	3,643		$	165		$	179		$	188
Interest cost	7,370			6,941			6,401			458			519			538
Expected return on plan assets	(5,904		)	(5,453		)	(4,976		)	—			—			—
Amortization of unrecognized:
Transition obligation, net	52			57			57			58			58			58
Prior service costs	16			29			43			—			—			—
Actuarial loss, net	3,586			2,636			2,538			227			276			257
Net periodic cost before regulatory adjustment	10,077			8,354			7,706			908			1,032			1,041
Regulatory adjustment	(2,546		)	(1,498		)	(945		)	—			—			—
Net periodic cost	$	7,531		$	6,856		$	6,761		$	908		$	1,032		$	1,041

Other Changes in Plan Assets and Benefit Obligations Recognized in Regulatory Assets:
Current year actuarial (gain)/loss	$	29,124		$	7,514		$	(3,407	)	$	(360	)	$	363		$	708
Amortization of actuarial loss	(3,586		)	(2,636		)	(2,538		)	(227		)	(276		)	(257		)
Amortization of prior service cost	(16		)	(29		)	(43		)	—			—			—
Amortization of transition obligation	(52		)	(57		)	(57		)	(58		)	(58		)	(58		)
Total recognized in regulatory assets	$	25,470		$	4,792		$	(6,045	)	$	(645	)	$	29		$	393

Total recognized in net periodic cost and regulatory assets	$	33,001		$	11,648		$	716		$	263		$	1,061		$	1,434

Weighted-Average Actuarial Assumptions used to Determine Net Periodic Cost:
Discount rate	5.45		%	6.05		%	6.15		%	4.90		%	5.50		%	6.05		%
Expected long-term return on plan assets	7.50		%	8.00		%	8.00		%	—			—			—
Compensation rate increase	4.00		%	4.00		%	4.00		%	—			—			—

We estimate that we will amortize the following amounts from regulatory assets into net periodic cost in 2012.



	Pension Benefits		Post-retirement Benefits
	(In Thousands)

Actuarial loss	$	5,368	$	233
Prior service cost	6		—
Transition obligation	—		58
Total	$	5,374	$	291

The expected long-term rate of return on plan assets is based on historical and projected rates of return for current and planned asset classes in the plans' investment portfolios. Assumed projected rates of return for each asset class were selected after analyzing long-term historical experience and future expectations of the volatility of the various asset classes. Based on target asset allocations for each asset class, the overall expected rate of return for the portfolios was developed, adjusted for historical and expected experience of active portfolio management results compared to benchmark returns and for the effect of expenses paid from plan assets.

For measurement purposes, the assumed annual health care cost growth rates were as follows.



	As of December 31,
	2011		2010

Health care cost trend rate assumed for next year	8.0	%	8.0	%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate)	5.0	%	5.0	%

Year that the rate reaches the ultimate trend rate	2018		2018

The health care cost trend rate affects the projected benefit obligation. A 1% change in assumed health care cost growth rates would have effects shown in the following table.



	One-Percentage- Point Increase			One-Percentage- Point Decrease
	(In Thousands)

Effect on total of service and interest cost	$	(8	)	$	8
Effect on post-retirement benefit obligation	(107		)	103

Plan Assets

The Wolf Creek pension plan investment strategy supports the objective of the trust, which is to earn the highest possible return on plan assets consistent with a reasonable and prudent level of risk. Investments are diversified across classes, sectors and manager style to maximize returns and minimize the risk of large losses. Wolf Creek delegates investment management to specialists in each asset class and, where appropriate, provides the investment managers with specific guidelines, which include allowable and/or prohibited investment types. Prohibited investments include investments in the equity or debt securities of the companies that collectively own Wolf Creek or companies that control such companies, which includes our and KGE securities, except as may occur indirectly through investments in diversified mutual funds. Wolf Creek has also established restrictions for certain classes of plan assets including that international equity securities should not exceed 25% of total plan assets, no more than 5% of the market value of the plan assets should be invested in the common stock of one corporation and the equity investment in any one corporation should not exceed 1% of its outstanding common stock. Wolf Creek measures and monitors investment risk on an ongoing basis through quarterly investment portfolio reviews and annual liability measurements. Wolf Creek post-retirement benefit plan assets are cash.

The target allocations for Wolf Creek's pension plan assets are 22% to international equity securities, 43% to domestic equity securities, 25% to debt securities, 5% to real estate securities and 5% to commodity investments. The investments in both international and domestic equity include investments in large-, mid- and small-cap companies, private equity funds and investment funds with underlying investments similar to those previously mentioned. The investments in debt include core and high-yield bonds. Core bonds include funds invested in investment grade debt securities of corporate entities, obligations of U.S. and foreign governments and their agencies, and private debt securities. High-yield bonds include a fund with underlying investments in non-investment grade debt securities of corporate entities, private placements and bank debt. Real estate securities include funds invested in commercial and residential real estate properties while commodity investments include funds invested in commodity-related instruments.

Wolf Creek's investments in equity, debt and commodity instruments are recorded at fair value using quoted market prices or valuation models utilizing observable market data when available. A portion of the investments is comprised of real estate securities that require significant unobservable market information to measure the fair value of the investments. Real estate securities are measured at fair value using a combination of market- and income-based models utilizing market discount rates, projected cash flows and the estimated value into perpetuity.

Similar to other assets measured at fair value, GAAP establishes a hierarchal framework for disclosing the transparency of the inputs utilized in measuring pension and post-retirement benefit plan assets at fair value. From time to time, the Wolf Creek pension trust may buy and sell investments resulting in changes within the hierarchy. See Note 4, "Financial and Derivative Instruments, Trading Securities, Energy Marketing and Risk Management," for a description of the hierarchal framework.

The following table provides the fair value of KGE's 47% share of Wolf Creek's pension plan assets and the corresponding level of hierarchy as of December 31, 2011 and 2010.



As of December 31, 2011	Level 1		Level 2		Level 3		Total
	(In Thousands)
Assets:
Domestic equity	$	30,753	$	—	$	—	$	30,753
International equity	9,953		8,070		—		18,023
Core bonds	—		17,877		—		17,877
High-yield bonds	4,102		—		—		4,102
Real estate securities	—		—		3,630		3,630
Commodities	—		4,377		—		4,377
Cash equivalents	—		1,965		—		1,965
Total Assets Measured at Fair Value	$	44,808	$	32,289	$	3,630	$	80,727

As of December 31, 2010

Assets:
Domestic equity	$	31,492	$	—	$	—	$	31,492
International equity	9,036		9,597		—		18,633
Core bonds	—		14,156		—		14,156
High-yield bonds	3,319		—		—		3,319
Real estate securities	—		—		3,160		3,160
Commodities	—		4,558		—		4,558
Cash equivalents	1		767		—		768
Total Assets Measured at Fair Value	$	43,848	$	29,078	$	3,160	$	76,086

The following table provides a reconciliation of KGE's 47% share of Wolf Creek's pension plan assets measured at fair value using significant level 3 inputs for the years ended December 31, 2011 and 2010.




	Real Estate Securities
	(In Thousands)

Balance as of December 31, 2010	$	3,160
Actual gain (loss) on plan assets:
Relating to assets still held at the reporting date	500
Relating to assets sold during the period	2
Purchases, issuances and settlements, net	(32		)
Balance as of December 31, 2011	$	3,630

Balance as of December 31, 2009	$	2,416
Actual gain (loss) on plan assets:
Relating to assets still held at the reporting date	393
Relating to assets sold during the period	(2		)
Purchases, issuances and settlements, net	353
Balance as of December 31, 2010	$	3,160

Cash Flows

The following table shows our expected cash flows for KGE's 47% share of Wolf Creek's pension and post-retirement benefit plans for future years.



Expected Cash Flows	Pension Benefits						Post-retirement Benefits
	To/(From) Trust			To/(From) Company Assets			To/(From) Trust		To/(From) Company Assets
	(In Millions)
Expected contributions:
2012	$	11.5		$	0.2		$	—	$	0.6

Expected benefit payments:
2012	$	(3.4	)	$	(0.2	)	$	—	$	(0.6	)
2013	(3.9		)	(0.2		)	—		(0.7		)
2014	(4.4		)	(0.2		)	—		(0.7		)
2015	(5.1		)	(0.2		)	—		(0.7		)
2016	(5.9		)	(0.2		)	—		(0.8		)
2017 - 2021	(43.3		)	(1.0		)	—		(4.0		)

Savings Plan

Wolf Creek maintains a qualified 401(k) savings plan in which most of its employees participate. They match employees' contributions in cash up to specified maximum limits. Wolf Creek's contributions to the plan are deposited with a trustee and invested at the direction of plan participants into one or more of the investment alternatives provided under the plan. KGE's portion of the expense associated with Wolf Creek's matching contributions was $1.3 million in 2011, $1.1 million in 2010 and $1.1 million in

Commitments And Contingencies

12 Months Ended

Dec. 31, 2011

Commitments and Contingencies Disclosure [Abstract]

Commitments And Contingencies

COMMITMENTS AND CONTINGENCIES

Purchase Orders and Contracts

As part of our ongoing operations and capital expenditure program, we have purchase orders and contracts, excluding fuel, which is discussed below under "- Purchased Power and Fuel Commitments," that had an unexpended balance of approximately $560.6 million as of December 31, 2011, of which $410.8 million had been committed. These commitments relate to purchase obligations issued and outstanding at year-end.

The yearly detail of the aggregate amount of required payments as of December 31, 2011, was as follows.




	Committed Amount
	(In Thousands)

2012	$	263,076
2013	72,121
2014	54,113
Thereafter	21,491
Total amount committed	$	410,801

Federal Clean Air Act

We must comply with the federal Clean Air Act, state laws and implementing federal and state regulations that impose, among other things, limitations on pollutants generated from our operations, including sulfur dioxide (SO₂), particulate matter (PM), nitrogen oxides (NOx), carbon monoxide (CO) and mercury.

Emissions from our generating facilities, including PM, SO₂ and NOx, have been determined by regulation to reduce visibility by causing or contributing to regional haze. Under federal laws, such as the Clean Air Visibility Rule, and pursuant to an agreement with the Kansas Department of Health and Environment (KDHE) and Environmental Protection Agency (EPA), we are required to install and maintain controls to reduce emissions found to cause or contribute to regional haze.

Under the federal Clean Air Act, the EPA sets National Ambient Air Quality Standards (NAAQS) for six criteria pollutants considered harmful to public health and the environment, including PM, NOx, CO and SO₂, which result from coal combustion. Areas meeting the NAAQS are designated attainment areas while those that do not meet the NAAQS are considered nonattainment areas. Each state must develop a plan to bring nonattainment areas into compliance with the NAAQS. NAAQS must be reviewed by the EPA at five-year intervals. In 2009, KDHE proposed to designate portions of the Kansas City area nonattainment for the 8-hour ozone standard, which has the potential to impact our operations.

In 2010, the EPA strengthened the NAAQS for both NOx and SO₂. We are currently evaluating what impact this could have on our operations. If we are required to install additional equipment to control emissions at our facilities, the revised NAAQS could have a material impact on our operations and consolidated financial results.

Environmental Projects

We will continue to make significant capital and operating expenditures at our power plants to reduce regulated emissions. The amount of these expenditures could change materially depending on the timing and nature of required investments, the specific outcomes resulting from interpretation of existing regulations, new regulations, legislation and the manner in which we operate the plants. In addition to the capital investment, in the event we install new equipment, such equipment may cause us to incur significant increases in annual operating and maintenance expense and may reduce the net production, reliability and availability of the plants. The degree to which we will need to reduce emissions and the timing of when such emissions controls may be required is uncertain. Additionally, our ability to access capital markets and the availability of materials, equipment and contractors may affect the timing and ultimate amount of such capital investments.

In comparison to a general rate review, the ECRR reduces the amount of time it takes to begin collecting in retail prices the costs associated with capital expenditures for qualifying environmental improvements. As previously discussed, we are not allowed to use the ECRR to collect our approximately $600.0 million share of the costs associated with the $1.2 billion of environmental upgrades at La Cygne. We must file for a general review of our rates or an abbreviated rate review with the KCC in order to collect these costs. In order to change our prices to collect increased operating and maintenance costs, we must file a general rate review with the KCC.

Air Emissions

The operation of power plants results in emissions of PM, mercury and other air toxics. In December 2011, the EPA finalized Mercury and Air Toxics Standards for power plants, which replaces the prior federal Clean Air Mercury Rule and requires significant reductions in emissions of mercury and other air toxics. Companies impacted by the new standards will have up to four years, and in certain limited circumstances up to five years, to comply. We are currently evaluating the new standards and cannot at this time determine the impact they may have on our operations and consolidated financial results, but we believe the cost of compliance could be material.

In July 2011, the EPA finalized the Cross-State Air Pollution Rule (CSAPR) which requires 28 states, including Kansas, Missouri and Oklahoma, to further reduce power plant emissions of SO₂ and NOx. Under CSAPR, reductions in annual SO₂ and NOx emissions were scheduled to begin January 1, 2012, with further reductions required beginning January 1, 2014. The EPA issued federal implementation plans for each state covered by CSAPR, but would allow these states to submit their own implementation plans starting as early as 2013. In October 2011, we filed legal challenges to CSAPR in the U.S. Court of Appeals for the District of Columbia Circuit.

In December 2011, the EPA published a final supplemental rule to CSAPR requiring five states to make summertime reductions in NOx emissions under an ozone-season control program implemented under CSAPR. Reductions in ozone-season NOx under this rule were scheduled to begin May 1, 2012. Although Kansas was included in the original proposed rules, the final supplemental rule instead calls for the EPA to revisit Kansas' status under this supplemental rule once Kansas submits an ozone state implementation plan, which must occur within 12 to 18 months from the date the EPA issues a state implementation call to Kansas. The EPA has not yet issued such a call.

On December 30, 2011, the U.S. Court of Appeals for the District of Columbia Circuit issued its ruling to stay CSAPR, including the final supplemental rule, pending judicial review, which delays CSAPR's implementation date beyond January 1, 2012. The court is scheduled to hear the cases starting in April 2012. Under this timeframe, the court could issue its decision by summer or early fall 2012. As the outcome of the judicial review and any other possible legal or Congressional challenges are uncertain, we are unable to determine what impact CSAPR may ultimately have on our operations and consolidated financial results, but it could be material.

Greenhouse Gases

Under EPA regulations finalized in May 2010, known as the tailoring rule, the EPA is regulating greenhouse gas (GHG) emissions from certain stationary sources. The regulations are being implemented pursuant to two federal Clean Air Act programs: the Title V Operating Permit program and the program requiring a permit if undergoing construction or major modifications, which is referred to as the Prevention of Significant Deterioration program (PSD). Obligations relating to Title V permits include recordkeeping and monitoring requirements. With respect to PSD permits, projects that cause a significant increase in GHG emissions (currently defined to be more than 75,000 tons or more per year or 100,000 tons or more per year, depending on various factors), are required to implement best available control technology (BACT). The EPA has issued guidance on what BACT entails for the control of GHGs and individual states are now required to determine what controls are required for facilities within their jurisdiction on a case-by-case basis. We cannot at this time determine the impact of these new regulations on our operations and consolidated financial results, but we believe the cost of compliance with new regulations could be material.

Renewable Energy Standard

Kansas law mandates that our capacity consists of a certain amount of renewable sources. In years 2011 through 2015 net renewable generation capacity must be 10% of the average peak demand for the three prior years, subject to limited exceptions. This requirement increases to 15% for years 2016 through 2019 and 20% for 2020 and thereafter. We met the 2011 requirement using our existing approximately 300 MW of qualifying wind generation facilities along with renewable energy credits. Beginning in late 2012, we will purchase under 20-year supply contracts the renewable energy produced from an additional approximately 370 MW of wind generation, which will allow us to satisfy the net renewable generation requirement through 2015 and contribute toward meeting the increased requirements beginning in 2016. If we are unable to meet future requirements, our operations and consolidated financial results could be adversely impacted.

Manufactured Gas Sites

We have been identified as being partially responsible for remediating a number of former manufactured gas sites located in Kansas. We and KDHE entered into a consent agreement governing all future work at these sites. Under terms of the consent agreement, we agreed to investigate and, if necessary, remediate these sites. Pursuant to an environmental indemnity agreement, ONEOK Inc. (ONEOK) assumed total liability for remediation of seven sites and we share liability for remediation with ONEOK for five sites. Our total liability for the five shared sites is capped at $3.8 million and terminates in November 2012.

Our environmental liability for remediation of former manufactured gas sites in Missouri associated with assets we divested many years ago had been limited to $7.5 million by the terms of an environmental indemnity agreement with the purchaser of those assets. In June 2010, the purchaser agreed to reduce our liability to $2.5 million, which reflects our share of the purchaser's expected remediation costs. We settled this liability in 2010.

EPA Lawsuit

In 2010, we settled a lawsuit filed by the Department of Justice on behalf of the EPA. We agreed to certain initial requirements as part of the settlement and also agreed to take further steps contingent on the outcome of the effectiveness of the initial requirements. As part of the initial requirements, we will install a selective catalytic reduction (SCR) on one of three JEC coal units by the end of 2014, which we estimate will cost approximately $240.0 million. Depending on the NOx emission reductions attained by the single SCR and attainable through the installation of other controls on the other two JEC coal units, we may have to install an SCR on another JEC unit by the end of 2016, if needed to meet plant-wide NOx reduction targets. We plan to recover the costs to install these systems through our ECRR, but such recovery remains subject to the approval of our regulators.

FERC Investigation

A non-public investigation by FERC of our use of transmission service between July 2006 and February 2008 remains pending. In May 2009, FERC staff alleged that we improperly used secondary network transmission service to facilitate off-system wholesale power sales in violation of applicable FERC orders and Southwest Power Pool (SPP) tariffs. FERC staff first alleged we received $14.3 million of unjust profits through such activities. We sent a response to FERC staff disputing both the legal basis for its allegations and their factual underpinnings. Based on our response, FERC staff substantially revised downward its preliminary conclusions to allege that we received $3.0 million of unjust profits and failed to pay $3.2 million to the SPP for transmission service. In March 2010, we sent a response to FERC staff disputing its revised conclusions. Following additional communications with FERC staff, FERC staff further revised its preliminary conclusions to allege that we have received $0.9 million of unjust profits and failed to pay $0.8 million to the SPP for transmission service. Although we continue to believe our use of transmission service was in compliance with FERC orders and SPP tariffs, we recorded an estimated liability of $0.5 million as of December 31, 2011, related to the potential settlement of this investigation and the risks of litigating this matter to a final outcome. We are unable to predict the outcome of this investigation or its impact on our consolidated financial results, but an adverse outcome could result in payments for alleged unjust profits and unpaid transmission costs as well as penalties, the amounts of which could be material, and could potentially alter the manner in which we are permitted to buy and sell energy and use transmission service.

Nuclear Decommissioning

Nuclear decommissioning is a nuclear industry term for the permanent shutdown of a nuclear power plant and the removal of radioactive components in accordance with Nuclear Regulatory Commission (NRC) requirements. The NRC will terminate a plant's license and release the property for unrestricted use when a company has reduced the residual radioactivity of a nuclear plant to a level mandated by the NRC. The NRC requires companies with nuclear plants to prepare formal financial plans to fund nuclear decommissioning. These plans are designed so that sufficient funds required for nuclear decommissioning will be accumulated prior to the expiration of the license of the related nuclear power plant. Wolf Creek files a nuclear decommissioning site study with the KCC every three years.

The KCC reviews nuclear decommissioning plans in two phases. Phase one is the approval of the revised nuclear decommissioning study including the estimated costs to decommission the plant. Phase two involves the review and approval of a funding schedule prepared by the owner of the plant detailing how it plans to fund the future-year dollar amount of its pro rata share of the decommissioning costs.

In 2011 we revised the nuclear decommissioning study. Based on the study, our share of decommissioning costs, including decontamination, dismantling and site restoration, is estimated to be $296.2 million. This amount compares to the prior site study estimate of $279.0 million. The site study cost estimate represents the estimate to decommission Wolf Creek as of the site study year. The actual nuclear decommissioning costs may vary from the estimates because of changes in regulations and technologies as well as changes in costs for labor, materials and equipment.

We are allowed to recover nuclear decommissioning costs in our prices over a period equal to the operating license of Wolf Creek, which is through 2045. The NRC requires that funds sufficient to meet nuclear decommissioning obligations be held in a trust. We believe that the KCC approved funding level will also be sufficient to meet the NRC requirement. Our consolidated financial results would be materially affected if we were not allowed to recover in our prices the full amount of the funding requirement.

We recovered in our prices and deposited in an external trust fund for nuclear decommissioning approximately $3.2 million in 2011, $3.1 million in 2010 and $2.9 million in 2009. We record our investment in the NDT fund at fair value, which approximated $130.3 million and $127.0 million as of December 31, 2011 and 2010, respectively.

Storage of Spent Nuclear Fuel

Under the Nuclear Waste Policy Act of 1982, the Department of Energy (DOE) is responsible for the permanent disposal of spent nuclear fuel. Wolf Creek pays into a federal Nuclear Waste Fund administered by the DOE a quarterly fee for the future disposal of spent nuclear fuel. Our share of the fee, calculated as one tenth of a cent for each kilowatt-hour of net nuclear generation delivered to customers, was $3.1 million in 2011, $4.0 million in 2010 and $3.7 million in 2009. We include these costs in fuel and purchased power expense on our consolidated statements of income.

In 2010, the DOE filed a motion with the NRC to withdraw its then pending application to construct a national repository for the disposal of spent nuclear fuel and high-level radioactive waste at Yucca Mountain, Nevada. An NRC board denied the DOE's motion to withdraw its application and the DOE appealed that decision to the full NRC. In 2011, the NRC issued an evenly split decision on the appeal and also ordered the licensing board to close out its work on the DOE's application by the end of 2011 due to a lack of funding. These agency actions prompted the States of Washington and South Carolina, and a county in South Carolina, to file a lawsuit in a federal Court of Appeals asking the court to compel the NRC to resume its license review and to issue a decision on the license application. Oral argument to the court is expected in 2012. Wolf Creek has an on-site storage facility designed to hold all spent fuel generated at the plant through 2025 and believes it will be able to expand on-site storage as needed past 2025. We cannot predict when, or if, an alternative disposal site will be available to receive Wolf Creek's spent nuclear fuel and will continue to monitor this activity.

Wolf Creek disposes of most of its low-level radioactive waste at an existing third-party repository in Utah, which we expect will remain available to Wolf Creek. Wolf Creek also contracts with a waste processor to process, take title and store in another state most of the remainder of Wolf Creek's low-level radioactive waste. Should on-site waste storage be needed in the future, Wolf Creek has storage capacity on site adequate for about four years of plant operations and believes it will be able to expand that storage capacity if needed.

Nuclear Insurance

We maintain nuclear insurance for Wolf Creek in four areas: liability, worker radiation, property and accidental outage. These policies contain certain industry standard exclusions, including, but not limited to, ordinary wear and tear and war. The nuclear liability program subscribed to by members of the nuclear power generating industry no longer include industry aggregate limits for non-certified acts, as defined by the Terrorism Risk Insurance Act, of terrorism-related losses. An industry aggregate limit of $3.2 billion plus any reinsurance recoverable by Nuclear Electric Insurance Limited (NEIL), our insurance provider, exists for property claims, including accidental outage power costs, for acts of terrorism affecting Wolf Creek or any other nuclear energy facility property policy within 12 months from the date of the first act. These limits are the maximum amount to be paid to members who sustain losses or damages from these types of terrorist acts. In addition, we may be required to participate in industry-wide retrospective assessment programs as discussed below.

Nuclear Liability Insurance

Pursuant to the Price-Anderson Act, which has been reauthorized through December 31, 2025, by the Energy Policy Act of 2005, we are required to insure against public liability claims resulting from nuclear incidents to the full limit of public liability, which is currently approximately $12.6 billion. This limit of liability consists of the maximum available commercial insurance of $375.0 million and the remaining $12.2 billion is provided through mandatory participation in an industry-wide retrospective assessment program. Under this retrospective assessment program, the owners of Wolf Creek are jointly and severally subject to an assessment of up to $117.5 million (our share is $55.2 million), payable at no more than $17.5 million (our share is $8.2 million) per incident per year per reactor. Both the total and yearly assessment is subject to an inflation adjustment based on the Consumer Price Index and applicable premium taxes. This assessment also applies in excess of our worker radiation claims insurance. The next scheduled inflation adjustment is scheduled for 2013. In addition, Congress could impose additional revenue-raising measures to pay claims.

Nuclear Property Insurance

The owners of Wolf Creek carry decontamination liability, premature nuclear decommissioning liability and property damage insurance for Wolf Creek totaling approximately $2.8 billion (our share is $1.3 billion). This insurance is provided by NEIL. In the event of an accident, insurance proceeds must first be used for reactor stabilization and site decontamination in accordance with a plan mandated by the NRC. Our share of any remaining proceeds can be used to pay for property damage, decontamination expenses or, if certain requirements are met, including nuclear decommissioning the plant, toward a shortfall in the NDT fund.

Accidental Nuclear Outage Insurance

The owners also carry additional insurance with NEIL to cover costs of replacement power and other extra expenses incurred during a prolonged outage resulting from accidental property damage at Wolf Creek. If significant losses were incurred at any of the nuclear plants insured under the NEIL policies, we may be subject to retrospective assessments under the current policies of approximately $30.9 million (our share is $14.5 million).

Although we maintain various insurance policies to provide coverage for potential losses and liabilities resulting from an accident or an extended outage, our insurance coverage may not be adequate to cover the costs that could result from a catastrophic accident or extended outage at Wolf Creek. Any substantial losses not covered by insurance, to the extent not recoverable in our prices, would have a material effect on our consolidated financial results.

Fuel and Purchased Power Commitments

To supply a portion of the fuel requirements for our power plants, the owners of Wolf Creek have entered into various contracts to obtain nuclear fuel and we have entered into various contracts to obtain coal and natural gas. Some of these contracts contain provisions for price escalation and minimum purchase commitments. As of December 31, 2011, our share of Wolf Creek's nuclear fuel commitments was approximately $38.4 million for uranium concentrates expiring in 2017, $5.8 million for conversion expiring in 2017, $116.1 million for enrichment expiring in 2024 and $43.0 million for fabrication expiring in 2024.

As of December 31, 2011, our coal and coal transportation contract commitments in 2011 dollars under the remaining terms of the contracts were approximately $886.0 million. The contracts are for plants that we operate and expire at various times through 2021.

As of December 31, 2011, our natural gas transportation contract commitments in 2011 dollars under the remaining terms of the contracts were approximately $145.9 million. The natural gas transportation contracts provide firm service to several of our natural gas burning facilities and expire at various times through 2030.

We have purchase power agreements with the owners of two separate wind generation facilities with installed design capacities of 146 MW. The agreements expire in late 2028 and early 2029. In addition, we have entered into two separate agreements with third parties to purchase under 20-year supply contracts the renewable energy produced from approximately 370 MW of wind generation beginning in late 2012. Each of the aforementioned agreements provide for our receipt and purchase of energy produced at a fixed price per unit of output. We estimate that our annual cost of energy purchased from these wind generation facilities will be approximately $31.7 million in 2012 and $68.2 million beginning in 2013.

The entire disclosure for commitments and contingencies.

Asset Retirement Obligation [Abstract]

Reference 1: http://www.xbrl.org/2003/role/presentationRef

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-Name FASB Interpretation (FIN)

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 5

-Paragraph 9, 10, 11, 12

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

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-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

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+ Details

Asset Retirement Obligations

12 Months Ended

Dec. 31, 2011

Asset Retirement Obligations

ASSET RETIREMENT OBLIGATIONS

Legal Liability

We have recognized legal obligations associated with the disposal of long-lived assets that result from the acquisition, construction, development or normal operation of such assets. The recording of AROs for regulated operations has no income statement impact due to the deferral of the adjustments through the establishment of a regulatory asset.

We initially recorded AROs at fair value for the estimated cost to decommission Wolf Creek (KGE's 47% share), retire our wind generation facilities, dispose of asbestos insulating material at our power plants, remediate ash disposal ponds and dispose of polychlorinated biphenyl (PCB)-contaminated oil.

The following table summarizes our legal AROs included on our consolidated balance sheets in long-term liabilities.



	As of December 31,
	2011			2010
	(In Thousands)
Beginning ARO	$	125,999		$	119,519
Liabilities incurred	—			—
Liabilities settled	(1,027		)	(738		)
Accretion expense	7,623			7,218
Increase in nuclear decommissioning ARO liability	9,913			—
Ending ARO	$	142,508		$	125,999

As discussed in Note 13, "Commitments and Contingencies—Nuclear Decommissioning," Wolf Creek filed a nuclear decommissioning study with the KCC in 2011. As a result of the study, we recorded a $9.9 million increase in our ARO to reflect revisions to the estimated costs to decommission Wolf Creek.

Conditional ARO refers to a legal obligation to perform an asset retirement activity in which the timing and/or method of settlement are conditional on a future event that may or may not be within the control of the entity. We determined that our conditional AROs include the retirement of our wind generation facilities, disposal of asbestos insulating material at our power plants, the remediation of ash disposal ponds and the disposal of PCB-contaminated oil.

We have an obligation to retire our wind generation facilities and remove the foundations. The ARO related to our wind generation facilities was determined based upon the date each wind generation facility was placed into service.

The amount of the retirement obligation related to asbestos disposal was recorded as of 1990, the date when the EPA published the "National Emission Standards for Hazardous Air Pollutants: Asbestos NESHAP Revision; Final Rule."

We operate, as permitted by the state of Kansas, ash landfills at several of our power plants. The ash landfills retirement obligation was determined based upon the date each landfill was originally placed in service.

PCB-contaminated oil is contained within company electrical equipment, primarily transformers. The PCB retirement obligation was determined based upon the PCB regulations that originally became effective in 1978.

Non-Legal Liability - Cost of Removal

We collect in our prices the costs to dispose of plant assets that do not represent legal retirement obligations. As of December 31, 2011 and 2010, we had $82.3 million and $70.3 million, respectively, in amounts collected, but not yet spent, for removal costs classified as a regulatory liability.

Common Stock, Number of Shares, Par Value and Other Disclosures [Abstract]

The entire disclosure for an asset retirement obligation and the associated long-lived asset. An asset retirement obligation is a legal obligation associated with the disposal or retirement from service of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

+ References+ Details

Legal Proceedings	12 Months Ended
Legal Proceedings	Dec. 31, 2011
Legal Proceedings [Abstract]
Legal Proceedings	LEGAL PROCEEDINGS In late 2002, one of our former executive officers resigned from his position and another executive officer was placed on administrative leave from his position. Following the completion of an investigation and the publication of a report prepared by a special committee of our board of directors, our board of directors determined that their employment was terminated for cause. In June 2003, we filed a demand for arbitration with the American Arbitration Association asserting claims against them arising out of their previous employment and seeking to avoid payment of compensation not yet paid to them under various plans and agreements. They filed counterclaims against us alleging substantial damages related to the termination of their employment and the publication of the report of the special committee. The arbitration was stayed in August 2004 pending final resolution of criminal charges filed against them in U.S. District Court in the District of Kansas. In August 2010, these criminal charges were dismissed and subsequently the stay of the arbitration was lifted. As of December 31, 2010, we had accrued liabilities of $80.6 million for compensation not yet paid to the former executive officers and $8.3 million for legal fees and expenses they had incurred. In May 2011, we reached an agreement with Douglas T. Lake, one of the former executive officers, settling all contractual obligations. Pursuant to the agreement, we paid him approximately $21.0 million and we paid approximately $5.3 million for his legal fees and expenses. In July 2011, we reached an agreement with David C. Wittig, the other former executive officer, settling all contractual obligations and providing for payments totaling approximately $36.0 million, the release of deferred stock for compensation shares and the payment of $3.1 million for his legal fees and expenses. In the third quarter of 2011, we reversed the remaining approximately $22.0 million of previously accrued liabilities, which reduced selling, general and administrative expense reported on our consolidated statement of income. We and our subsidiaries are involved in various other legal, environmental and regulatory proceedings. We believe that adequate provisions have been made and accordingly believe that the ultimate disposition of such matters will not have a material affect on our consolidated financial results. See Note 3, "Rate Matters and Regulation," and Note 13, "Commitments and Contingencies," for additional information.

Common and Preferred Stock

12 Months Ended

Dec. 31, 2011

Common Stock and Preferred Stock

COMMON AND PREFERRED STOCK

Common Stock

General

On May 19, 2011, Westar Energy shareholders approved an amendment to its Restated Articles of Incorporation to increase the number of shares of common stock authorized to be issued from 150.0 million to 275.0 million. As of December 31, 2011 and 2010, Westar Energy had issued and outstanding 125.7 million shares and 112.1 million shares, respectively.

Westar Energy has a direct stock purchase plan (DSPP). Shares of common stock sold pursuant to the DSPP may be either original issue shares or shares purchased in the open market. During 2011, 2010 and 2009, Westar Energy issued 0.8 million shares, 0.7 million shares and 0.8 million shares, respectively, through the DSPP and other stock-based plans operated under the LTISA Plan. As of December 31, 2011 and 2010, a total of 2.0 million shares and 2.6 million shares, respectively, were available under the DSPP registration statement.

Issuances

In November 2010, Westar Energy entered into a forward sale agreement with a bank. Under the terms of the agreement, the bank, as forward seller, borrowed 7.5 million shares of Westar Energy's common stock from third parties and sold them to a group of underwriters for $25.54 per share. Under an over-allotment option included in the agreement, the underwriters purchased approximately 1.0 million additional shares for $25.54 per share, which increased the total number of shares under the forward sale agreement to approximately 8.5 million shares. The underwriters receive a commission equal to 3.5% of the sales price of all shares sold under the agreement. Westar Energy agreed to settle the forward sale agreement within 18 months of the transaction date. On November 17, 2011, Westar Energy delivered approximately 8.5 million shares of common stock for proceeds of approximately $197.3 million as complete settlement of this forward sale agreement.

In April 2010, Westar Energy entered into a three-year Sales Agency Financing Agreement and forward sale agreement with a bank. The maximum amount that Westar Energy may offer and sell under the agreements is the lesser of an aggregate of $500.0 million or approximately 22.0 million shares, subject to adjustment for share splits, share combinations and share dividends. Under the terms of the Sales Agency Financing Agreement, Westar Energy may offer and sell shares of its common stock from time to time through the broker dealer subsidiary, as agent. The broker dealer receives a commission equal to 1% of the sales price of all shares sold under the agreement. In addition, under the terms of the Sales Agency Financing Agreement and forward sale agreement, Westar Energy may from time to time enter into one or more forward sale transactions with the bank, as forward purchaser, and the bank will borrow shares of Westar Energy's common stock from third parties and sell them through its broker dealer. Westar Energy must settle the forward sale transactions within one year of the date each transaction is entered. Westar Energy has entered into forward sale transactions with respect to an aggregate of approximately 5.4 million shares of common stock. In late 2010, Westar Energy delivered approximately 1.2 million shares of common stock for proceeds of $26.4 million as partial settlement of the forward sale transactions. Westar Energy delivered approximately 4.2 million shares of common stock in 2011 for proceeds of $91.9 million as complete settlement of this forward sale agreement.

Westar Energy used the proceeds from the issuance of common stock to repay borrowings under its revolving credit facility, with such borrowed amounts principally related to investments in capital equipment, as well as for working capital and general corporate purposes.

Preferred Stock Not Subject to Mandatory Redemption

Westar Energy's cumulative preferred stock is redeemable in whole or in part on 30 to 60 days' notice at our option. The table below shows the redemption amounts for all series of our preferred stock not subject to mandatory redemption as of December 31, 2011.



Rate	Shares	Principal Outstanding		Call Price	Premium		Total Cost to Redeem
(Dollars in Thousands)
4.50%	121,613	$	12,161	108.0%	$	973	$	13,134
4.25%	54,970	5,497		101.5%	82		5,579
5.00%	37,780	3,778		102.0%	76		3,854
	214,363	$	21,436		$	1,131	$	22,567

The provisions of Westar Energy's articles of incorporation, as amended, contain restrictions on the payment of dividends or the making of other distributions on its common stock while any preferred shares remain outstanding unless certain capitalization ratios and other conditions are met. If the ratio of the capital represented by Westar Energy's common stock, including premiums on its capital stock and its surplus accounts, to its total capital and its surplus accounts at the end of the second month immediately preceding the date of the proposed payment of dividends, adjusted to reflect the proposed payment (capitalization ratio), will be less than 20%, then the payment of the dividends on its common stock, including the proposed payment, during the 12-month period ending with and including the date of the proposed payment shall not exceed 50% of its net income available for dividends for the 12-month period ending with and including the second month immediately preceding the date of the proposed payment. If the capitalization ratio is 20% or more but less than 25%, then the payment of dividends on its common stock, including the proposed payment, during the 12-month period ending with and including the date of the proposed payment shall not exceed 75% of its net income available for dividends for the 12-month period ending with and including the second month immediately preceding the date of the proposed payment. Except to the extent permitted above, no payment or other distribution may be made that would reduce the capitalization ratio to less than 25%. The capitalization ratio is determined based on the unconsolidated balance sheet for Westar Energy. As of December 31, 2011, the capitalization ratio was greater than 25%.

So long as there are any outstanding shares of Westar Energy preferred stock, Westar Energy shall not without the consent of a majority of the shares of preferred stock or if more than one-third of the outstanding shares of preferred stock vote negatively and without the consent of a percentage of any and all classes required by law and Westar Energy's articles of incorporation, declare or pay any dividends (other than stock dividends or dividends applied by the recipient to the purchase of additional shares) or make any other distribution upon common stock unless, immediately after such distribution or payment the sum of Westar Energy's capital represented by its outstanding common stock and its earned and any capital surplus shall not be less than $10.5 million plus an amount equal to twice the annual dividend requirement on all the then outstanding shares of preferred stock.

Tabular disclosure of an entity's stock, including par or stated value per share, number and dollar amount of share subscriptions, shares authorized, shares issued, shares outstanding, number and dollar amount of shares held in an employee trust, dividend per share, total dividends, share conversion features, par value plus additional paid in capital, the value of treasury stock and other information necessary to a fair presentation, and EPS information. Stock by class includes common, convertible, and preferred stocks which are not redeemable or redeemable solely at the option of the issuer. Includes preferred stock with redemption features that are solely within the control of the issuer and mandatorily redeemable stock if redemption is required to occur only upon liquidation or termination of the reporting entity. If more than one issue is outstanding, state the title of each issue and the corresponding dollar amount; dollar amount of any shares subscribed but unissued and the deduction of subscriptions receivable there from; number of shares authorized, issued, and outstanding.

Variable Interest Entities [Abstract]

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+ Details

Variable Interest Entities

12 Months Ended

Dec. 31, 2011

Variable Interest Entities Disclosure [Text Block]

VARIABLE INTEREST ENTITIES

In determining the primary beneficiary of a VIE, we assess the entity's purpose and design, including the nature of the entity's activities and the risks that the entity was designed to create and pass through to its variable interest holders. A reporting enterprise is deemed to be the primary beneficiary of a VIE if it has (a) the power to direct the activities of the VIE that most significantly impact the VIE's economic performance and (b) the obligation to absorb losses or right to receive benefits from the VIE that could potentially be significant to the VIE. Accounting guidance effective January 1, 2010, requires the primary beneficiary of a VIE to consolidate the VIE. The trusts holding our 8% interest in JEC, our 50% interest in La Cygne unit 2 and railcars we use to transport coal to some of our plants are VIEs of which we are the primary beneficiary.

We assess all entities with which we become involved to determine whether such entities are VIEs and, if so, whether or not we are the primary beneficiary of the entities. We also continuously assess whether we are the primary beneficiary of the VIEs with which we are involved. Prospective changes in facts and circumstances may cause us to reconsider our determination as it relates to the identification of the primary beneficiary.

8% Interest in Jeffrey Energy Center

Under an agreement that expires in January 2019, we lease an 8% interest in JEC from a trust. The trust was financed with an equity contribution from an owner participant and debt issued by the trust. The trust was created specifically to purchase the 8% interest in JEC and lease it to a third party, and does not hold any other assets. We meet the requirements to be considered the primary beneficiary of the trust. In determining the primary beneficiary of the trust, we concluded that the activities of the trust that most significantly impact its economic performance and that we have the power to direct include (1) the operation and maintenance of the 8% interest in JEC, (2) our ability to exercise a purchase option at the end of the agreement at the lesser of fair value or a fixed amount and (3) our option to require refinancing of the trust's debt. We have the potential to receive benefits from the trust that could potentially be significant if the fair value of the 8% interest in JEC at the end of the agreement is greater than the fixed amount. The possibility of lower interest rates upon refinancing the debt also creates the potential for us to receive significant benefits.

50% Interest in La Cygne Unit 2

Under an agreement that expires in September 2029, KGE entered into a sale-leaseback transaction with a trust under which the trust purchased KGE's 50% interest in La Cygne unit 2 and subsequently leased it back to KGE. The trust was financed with an equity contribution from an owner participant and debt issued by the trust. The trust was created specifically to purchase the 50% interest in La Cygne unit 2 and lease it back to KGE, and does not hold any other assets. We meet the requirements to be considered the primary beneficiary of the trust. In determining the primary beneficiary of the trust, we concluded that the activities of the trust that most significantly impact its economic performance and that we have the power to direct include (1) the operation and maintenance of the 50% interest in La Cygne unit 2, (2) our ability to exercise a purchase option at the end of the agreement at the lesser of fair value or a fixed amount and (3) our option to require refinancing of the trust's debt. We have the potential to receive benefits from the trust that could potentially be significant if the fair value of the 50% interest in La Cygne unit 2 at the end of the agreement is greater than the fixed amount. The possibility of lower interest rates upon refinancing the debt also creates the potential for us to receive significant benefits.

Railcars

Under two separate agreements that expire in May 2013 and November 2014, we lease railcars from trusts to transport coal to some of our power plants. The trusts were financed with equity contributions from owner participants and debt issued by the trusts. The trusts were created specifically to purchase the railcars and lease them to us, and do not hold any other assets. We meet the requirements to be considered the primary beneficiary of the trusts. In determining the primary beneficiary of the trusts, we concluded that the activities of the trusts that most significantly impact their economic performance and that we have the power to direct include the operation, maintenance and repair of the railcars and our ability to exercise a purchase option at the end of the agreements at the lesser of fair value or a fixed amount. We have the potential to receive benefits from the trusts that could potentially be significant if the fair value of the railcars at the end of the agreements is greater than the fixed amounts. Our agreements with these trusts also include renewal options during which time we would pay a fixed amount of rent. We have the potential to receive benefits from the trusts during the renewal periods if the fixed amount of rent is less than the amount we would be required to pay under a new agreement.

Financial Statement Impact

We have recorded the following assets and liabilities on our consolidated balance sheets related to the VIEs described above.



	As of December 31,
	2011		2010
	(In Thousands)
Assets:
Property, plant and equipment of variable interest entities, net	$	333,494	$	345,037
Regulatory assets (a)	4,915		3,963

Liabilities:
Current maturities of long-term debt of variable interest entities	$	28,114	$	30,155
Accrued interest (b)	4,448		5,064
Long-term debt of variable interest entities, net	249,283		278,162

_______________

(a) Included in long-term regulatory assets on our consolidated balance sheets.

(b) Included in accrued interest on our consolidated balance sheets.

All of the liabilities noted in the table above relate to the purchase of the reported property, plant and equipment. The assets of the VIEs can be used only to settle obligations of the VIEs and the VIEs' debt holders have no recourse to our general credit. We have not provided financial or other support to the VIEs and are not required to provide such support. We did not record any gain or loss upon initial consolidation of the VIEs.

Variable Interest Entities

We have recorded the following assets and liabilities on our consolidated balance sheets related to the VIEs described above.



	As of December 31,
	2011		2010
	(In Thousands)
Assets:
Property, plant and equipment of variable interest entities, net	$	333,494	$	345,037
Regulatory assets (a)	4,915		3,963

Liabilities:
Current maturities of long-term debt of variable interest entities	$	28,114	$	30,155
Accrued interest (b)	4,448		5,064
Long-term debt of variable interest entities, net	249,283		278,162

_______________

(a) Included in long-term regulatory assets on our consolidated balance sheets.

(b) Included in accrued interest on our consolidated balance sheets.

Tabular disclosure of the significant judgments and assumptions made in determining whether a variable interest (as defined) held by the entity requires the variable interest entity (VIE) (as defined) to be consolidated and (or) disclose information about its involvement with the VIE, individually or in aggregate (as applicable); the nature of restrictions, if any, on the consolidated VIE's assets and on the settlement of its liabilities reported by an entity in its statement of financial position, including the carrying amounts of such assets and liabilities; the nature of, and changes in, the risks associated with involvement in the VIE; how involvement with the VIE affects the entity's financial position, financial performance, and cash flows; the lack of recourse if creditors (or beneficial interest holders) of the consolidated VIE have no recourse to the general credit of the primary beneficiary (if applicable); the terms of arrangements, giving consideration to both explicit arrangements and implicit variable interests, if any, that could require the entity to provide financial support to the VIE, including events or circumstances that could expose the entity to a loss; the methodology used by the entity for determining whether or not it is the primary beneficiary of the variable interest entity; the significant factors considered and judgments made in determining that the power to direct the activities of a VIE that most significantly impact the VIE's economic performance are shared (as defined); the carrying amounts and classification of assets and liabilities of the VIE included in the statement of financial position; the entity's maximum exposure to loss, if any, as a result of its involvement with the VIE, including how the maximum exposure is determined and significant sources of the entity's exposure to the VIE; a comparison of the carrying amounts of the assets and liabilities and the entity's maximum exposure to loss; information about any liquidity arrangements, guarantees, and (or) other commitments by third parties that may affect the fair value or risk of the entity's variable interest in the VIE; whether or not the entity has provided financial support or other support (explicitly or implicitly) to the VIE that it was not previously contractually required to provide or whether the entity intends to provide that support, including the type and amount of the support and the primary reasons for providing the support; and supplemental information the entity determines necessary to provide.

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+ Details

Leases

12 Months Ended

Dec. 31, 2011

Leases [Abstract]

Leases

LEASES

Operating Leases

We lease office buildings, computer equipment, vehicles, railcars and other property and equipment. These leases have various terms and expiration dates ranging from one to 20 years.

In determining lease expense, we recognize the effects of scheduled rent increases on a straight-line basis over the minimum lease term. Rental expense and estimated future commitments under operating leases are as follows.



Year Ended December 31,	Total Operating Leases
	(In Thousands)
Rental expense:
2009	$	38,096
2010 (a)	15,464
2011	17,577

Future commitments:
2012	$	16,247
2013	13,919
2014	11,820
2015	9,721
2016	8,393
Thereafter	17,520
Total future commitments	$	77,620

_______________

(a) In 2010, we began consolidating certain trusts that hold assets we lease as VIEs as discussed in Note 17, “Variable Interest Entities.” This eliminated the lease accounting we previously reported for these assets and, as a result, rental expense decreased significantly from 2009 to 2010.

Capital Leases

We identify capital leases based on defined criteria. For both vehicles and computer equipment, new leases are signed each month based on the terms of master lease agreements. The lease term for vehicles is from two to eight years depending on the type of vehicle. Computer equipment has a lease term of four to five years.

On April 28, 2011, FERC issued an order approving a power supply agreement. The agreement extend through May 2039, the terms of which meet the criteria such that it is classified as a capital lease. Accordingly, we recorded a $40.0 million capital lease during the second quarter of 2011.

Assets recorded under capital leases are listed below.



	As of December 31,
	2011			2010
	(In Thousands)
Vehicles	$	14,241		$	12,504
Computer equipment	1,720			5,551
Power plant	40,048			—
Accumulated amortization	(6,485		)	(8,744		)
Total capital leases	$	49,524		$	9,311

Capital leases are treated as operating leases for rate making purposes. Minimum annual rental payments, excluding administrative costs such as property taxes, insurance and maintenance, under capital leases are listed below.



Year Ended December 31,	Total Capital Leases
	(In Thousands)

2012	$	5,452
2013	5,200
2014	5,203
2015	4,987
2016	4,127
Thereafter	67,830
	92,799
Amounts representing imputed interest	(43,275		)
Present value of net minimum lease payments under capital leases	49,524
Less: Current portion	2,471
Total long-term obligation under capital leases	$	47,053

The entire disclosure for lessee entity's leasing arrangements including, but not limited to, all of the following: (a.) The basis on which contingent rental payments are determined, (b.) The existence and terms of renewal or purchase options and escalation clauses, (c.) Restrictions imposed by lease agreements, such as those concerning dividends, additional debt, and further leasing.

+ References+ Details

Discontinued Operations	12 Months Ended
Discontinued Operations	Dec. 31, 2011
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations	DISCONTINUED OPERATIONS — Sale of Protection One, Inc. In 2009, the Joint Committee on Taxation of the U.S. Congress approved a settlement with the IRS Office of Appeals regarding the re-characterization of a portion of the loss we incurred on the sale of Protection One, Inc. (Protection One), a former subsidiary, from a capital loss to an ordinary loss. The settlement involved a determination of the amount of the net capital loss and net operating loss carryforwards available as of December 31, 2004, to offset income in years after 2004. In 2009, we filed amended federal income tax returns for tax years 2005, 2006 and 2007 to claim a portion of the income tax benefits from the net operating loss carryforward. We expect to realize the remainder of the income tax benefits from the net operating loss carryforward in future years. We recorded a non-cash net earnings benefit of approximately $33.7 million, net of $22.8 million we paid Protection One, in discontinued operations in 2009 in recognition of this settlement.

The entire disclosure for the facts and circumstances leading to the completed or expected disposal, manner and timing of disposal, the gain (loss) recognized in the income statement and the income statement caption that includes that gain (loss), amounts of revenues and pretax profit or loss reported in discontinued operations, the segment in which the disposal group was reported, and the classification (whether sold or classified as held for sale) and carrying value of the assets and liabilities comprising the disposal group. Includes all disposal groups, including those classified as components of the entity (discontinued operations).

Quarterly Financial Information Disclosure [Abstract]

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+ Details

Quarterly Results (Unaudited)

12 Months Ended

Dec. 31, 2011

Quarterly Results (Unaudited)

QUARTERLY RESULTS (UNAUDITED)

Our business is seasonal in nature and, in our opinion, comparisons between the quarters of a year do not give a true indication of overall trends and changes in operations.



2011	First		Second		Third (a)		Fourth
	(In Thousands, Except Per Share Amounts)

Revenues (b)	$	481,720	$	524,892	$	678,152	$	486,228
Net income (b)	32,957		45,525		136,392		21,306
Net income attributable to common stock (b)	31,342		43,887		134,708		19,335

Per Share Data (b):

Basic:
Earnings available	$	0.27	$	0.38	$	1.15	$	0.16

Diluted:
Earnings available	$	0.27	$	0.38	$	1.14	$	0.16

Cash dividend declared per common share	$	0.32	$	0.32	$	0.32	$	0.32
Market price per common share:
High	$	26.60	$	27.98	$	27.29	$	29.05
Low	$	25.05	$	25.58	$	22.63	$	25.02

_______________

(a)

During the third quarter of 2011, we reversed $22.0 million of previously accrued liabilities as a result of the legal settlements discussed in Note 15,"Legal Proceedings," and recorded a $7.2 million gain on the sale of a non-utility investment. These two factors were the primary drivers for the increases in net income and net income attributable to common stock as compared to the third quarter of 2010.


(b)	Items are computed independently for each of the periods presented and the sum of the quarterly amounts may not equal the total for the year.



2010	First		Second		Third (a)		Fourth
	(In Thousands, Except Per Share Amounts)

Revenues (b)	$	459,830	$	495,181	$	644,437	$	456,723
Net income (b)	31,682		54,530		115,863		6,550
Net income attributable to common stock (b)	30,438		53,069		114,502		4,919

Per Share Data (b):

Basic:
Earnings available	$	0.27	$	0.47	$	1.02	$	0.04

Diluted:
Earnings available	$	0.27	$	0.47	$	1.01	$	0.04

Cash dividend declared per common share	$	0.31	$	0.31	$	0.31	$	0.31
Market price per common share:
High	$	22.78	$	23.93	$	24.64	$	25.90
Low	$	20.56	$	21.08	$	21.22	$	24.21

________________


(a)	In the third quarter of 2010, net income and net income attributable to common stock increased due principally to warmer than normal weather in our service territory. As measured by cooling degree days, the weather during the third quarter of 2010 was 20% warmer than the 20-year average.


(b)	Items are computed independently for each of the periods presented and the sum of the quarterly amounts may not equal the total for the year.

Valuation and Qualifying Accounts [Abstract]

The entire disclosure for the quarterly financial data in the annual financial statements. The disclosure may include a tabular presentation of financial information for each fiscal quarter for the current and previous year, including revenues, gross profit, income or loss before extraordinary items and earnings per share data. It also includes an indication if the information in the note is unaudited, comments on the aggregate effect of year-end adjustments, and an explanation of matters or transactions that affect comparability or are pertinent to an understanding of the information furnished.

+ References+ Details

Valuation and Qualifying Accounts

12 Months Ended

Dec. 31, 2011

Valuation and Qualifying Accounts

SCHEDULE II — VALUATION AND QUALIFYING ACCOUNTS



Description	Balance at Beginning of Period		Charged to Costs and Expenses		Deductions (a)			Balance at End of Period
	(In Thousands)
Year ended December 31, 2009
Allowances deducted from assets for doubtful accounts	$	4,810	$	5,797	$	(5,376	)	$	5,231

Year ended December 31, 2010
Allowances deducted from assets for doubtful accounts	$	5,231	$	8,337	$	(7,839	)	$	5,729

Year ended December 31, 2011
Allowances deducted from assets for doubtful accounts	$	5,729	$	8,774	$	(7,119	)	$	7,384

_______________


(a)	Result from write-offs of accounts receivable.

Summary Of Significant Accounting Policies (Policy)

12 Months Ended

Dec. 31, 2011

Accounting Policies [Abstract]

Principles Of Consolidation

Principles of Consolidation

Use Of Management's Estimates

Use of Management's Estimates

Regulatory Accounting [Policy Text Block]

Regulatory Accounting

Cash And Cash Equivalents

Cash and Cash Equivalents

We consider investments that are highly liquid and have maturities of three months or less when purchased to be cash equivalents.

Fuel Inventory And Supplies

Fuel Inventory and Supplies

We state fuel inventory and supplies at average cost.

Allowance For Funds Used During Construction

AFUDC represents the allowed cost of capital used to finance utility construction activity. We compute AFUDC by applying a composite rate to qualified construction work in progress. We credit other income (for equity funds) and interest expense (for borrowed funds) for the amount of AFUDC capitalized as construction cost on the accompanying consolidated statements of income

Property, Plant And Equipment

Property, Plant and Equipment



	Year Ended December 31,
	2011		2010			2009
	(Dollars In Thousands)
Borrowed funds	$	5,589	$	4,295		$	4,857
Equity funds	5,550		3,104			5,031
Total	$	11,139	$	7,399		$	9,888
Average AFUDC Rates	3.6%		2.6		%	4.2		%

Depreciation

We depreciate utility plant using a straight-line method. These rates are based on an average annual composite basis using group rates that approximated 3.0% in 2011, 2.9% in 2010 and 3.0% in 2009.

Depreciable lives of property, plant and equipment are as follows.



	Years
Fossil fuel generating facilities	7 to 78
Nuclear fuel generating facility	33 to 62
Wind generating facilities	19 to 20
Transmission facilities	15 to 67
Distribution facilities	15 to 70
Other	6 to 28

Capitalization and Amortization of Fuel Costs, Policy [Policy Text Block]

Nuclear Fuel

Revenue Recognition

Electricity Sales

Energy Marketing Contracts

Normal Purchases and Normal Sales Exception

Allowance For Doubtful Accounts

Allowance for Doubtful Accounts

Income Taxes

Sales Tax [Policy Text Block]

Sales Taxes

We account for the collection and remittance of sales tax on a net basis. As a result, we do not reflect sales tax in our consolidated statements of income.

Earnings Per Share

The following table reconciles our basic and diluted EPS from income from continuing operations.



	Year Ended December 31,
	2011		2010		2009
	(Dollars In Thousands, Except Per Share Amounts)
Income from continuing operations	$	236,180	$	208,624	$	141,330
Less: Income attributable to noncontrolling interests	5,941		4,728		—
Income from continuing operations attributable to Westar Energy	230,239		203,896		141,330
Less: Preferred dividends	970		970		970
Income from continuing operations allocated to RSUs	772		1,259		541
Income from continuing operations attributable to common stock	$	228,497	$	201,667	$	139,819

Weighted average equivalent common shares outstanding – basic	116,890,552		111,629,292		109,647,689
Effect of dilutive securities:
RSUs	188,025		140,077		—
Forward sale agreements	1,211,645		245,496		—
Employee stock options	—		59		481
Weighted average equivalent common shares outstanding – diluted (a)	118,290,222		112,014,924		109,648,170

Earnings from continuing operations per common share, basic	$	1.95	$	1.81	$	1.28
Earnings from continuing operations per common share, diluted	$	1.93	$	1.80	$	1.28

_______________


(a)	For the years ended December 31, 2011, 2010 and 2009, we had no antidilutive shares.

Supplemental Cash Flow Information



	Year Ended December 31,
	2011			2010			2009
	(In Thousands)
CASH PAID FOR (RECEIVED FROM):
Interest on financing activities, net of amount capitalized	$	145,570		$	145,463		$	144,964
Interest on financing activities of VIEs	18,167			20,191			—
Income taxes, net of refunds	(17,519		)	(34,980		)	(7,870		)
NON-CASH INVESTING TRANSACTIONS:
Property, plant and equipment additions	105,435			64,423			21,614
Property, plant and equipment additions of VIEs	—			356,964			—
Jeffrey Energy Center (JEC) 8% leasehold interest	—			(108,706		)	—
NON-CASH FINANCING TRANSACTIONS:
Issuance of common stock for reinvested dividends and compensation plans	15,103			18,777			12,168
Debt of VIEs	—			337,951			—
Capital lease for JEC 8% leasehold interest	—			(106,423		)	—
Assets acquired through capital leases	43,011			910			2,818

Summary Of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2011

Accounting Policies [Abstract]

Schedule of Utility Inventory

Following are the balances for fuel inventory and supplies stated separately.



	As of December 31,
	2011		2010
	(In Thousands)
Fuel inventory	$	86,408	$	79,938
Supplies	142,710		126,929
Total	$	229,118	$	206,867

Allowance For Funds Used During Construction

We credit other income (for equity funds) and interest expense (for borrowed funds) for the amount of AFUDC capitalized as construction cost on the accompanying consolidated statements of income as follows:



	Year Ended December 31,
	2011		2010			2009
	(Dollars In Thousands)
Borrowed funds	$	5,589	$	4,295		$	4,857
Equity funds	5,550		3,104			5,031
Total	$	11,139	$	7,399		$	9,888
Average AFUDC Rates	3.6%		2.6		%	4.2		%

Property, Plant and Equipment

Depreciable lives of property, plant and equipment are as follows.



	Years
Fossil fuel generating facilities	7 to 78
Nuclear fuel generating facility	33 to 62
Wind generating facilities	19 to 20
Transmission facilities	15 to 67
Distribution facilities	15 to 70
Other	6 to 28

Schedule Of Amounts Recognized In Balance Sheet, Related To Corporate-Owned Life Insurance Policies

We recorded on our consolidated balance sheets in other long-term assets the following amounts related to corporate-owned life insurance policies.



	As of December 31,
	2011			2010
	(In Thousands)
Cash surrender value of policies	$	1,345,443		$	1,280,615
Borrowings against policies	(1,208,389		)	(1,144,248		)
Corporate-owned life insurance, net	$	137,054		$	136,367

Reconciliation Of Basic And Diluted EPS

The following table reconciles our basic and diluted EPS from income from continuing operations.



	Year Ended December 31,
	2011		2010		2009
	(Dollars In Thousands, Except Per Share Amounts)
Income from continuing operations	$	236,180	$	208,624	$	141,330
Less: Income attributable to noncontrolling interests	5,941		4,728		—
Income from continuing operations attributable to Westar Energy	230,239		203,896		141,330
Less: Preferred dividends	970		970		970
Income from continuing operations allocated to RSUs	772		1,259		541
Income from continuing operations attributable to common stock	$	228,497	$	201,667	$	139,819

Weighted average equivalent common shares outstanding – basic	116,890,552		111,629,292		109,647,689
Effect of dilutive securities:
RSUs	188,025		140,077		—
Forward sale agreements	1,211,645		245,496		—
Employee stock options	—		59		481
Weighted average equivalent common shares outstanding – diluted (a)	118,290,222		112,014,924		109,648,170

Earnings from continuing operations per common share, basic	$	1.95	$	1.81	$	1.28
Earnings from continuing operations per common share, diluted	$	1.93	$	1.80	$	1.28

_______________


(a)	For the years ended December 31, 2011, 2010 and 2009, we had no antidilutive shares.

Supplemental Cash Flow Information



	Year Ended December 31,
	2011			2010			2009
	(In Thousands)
CASH PAID FOR (RECEIVED FROM):
Interest on financing activities, net of amount capitalized	$	145,570		$	145,463		$	144,964
Interest on financing activities of VIEs	18,167			20,191			—
Income taxes, net of refunds	(17,519		)	(34,980		)	(7,870		)
NON-CASH INVESTING TRANSACTIONS:
Property, plant and equipment additions	105,435			64,423			21,614
Property, plant and equipment additions of VIEs	—			356,964			—
Jeffrey Energy Center (JEC) 8% leasehold interest	—			(108,706		)	—
NON-CASH FINANCING TRANSACTIONS:
Issuance of common stock for reinvested dividends and compensation plans	15,103			18,777			12,168
Debt of VIEs	—			337,951			—
Capital lease for JEC 8% leasehold interest	—			(106,423		)	—
Assets acquired through capital leases	43,011			910			2,818

Schedule Of Regulatory Assets And Liabilities [Table Text Block]

Tabular disclosure of the useful life and salvage value of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale. Examples include land, buildings, machinery and equipment, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software.

+ References+ Details

Rate Matters And Regulation (Tables)

12 Months Ended

Dec. 31, 2011

Regulated Operations [Abstract]

Regulatory assets and liabilities reflected on our consolidated balance sheets are as follows.



	As of December 31,
	2011		2010
	(In Thousands)
Regulatory Assets:
Deferred employee benefit costs	$	560,915	$	431,016
Amounts due from customers for future income taxes, net	168,804		172,181
Depreciation	76,298		79,770
Debt reacquisition costs	66,856		73,099
Treasury yield hedges	33,753		—
Storm costs	25,747		34,741
Wolf Creek outage	25,033		9,637
Asset retirement obligations	22,196		21,546
Retail energy cost adjustment	19,587		—
Energy efficiency program costs	16,521		10,980
Disallowed plant costs	16,236		16,354
Ad valorem tax	6,622		5,680
Other regulatory assets	7,522		6,061
Total regulatory assets	$	1,046,090	$	861,065

Regulatory Liabilities:
Deferred regulatory gain from sale leaseback	$	97,541	$	103,036
Removal costs	82,338		70,342
Retail energy cost adjustment	25,225		16,402
La Cygne dismantling costs	15,680		13,268
Nuclear decommissioning	12,544		25,467
Other post-retirement benefits costs	11,125		6,943
Kansas tax credits	8,497		3,565
Fuel supply and electricity contracts	6,177		7,800
Ad valorem tax	—		4,934
Treasury yield hedges	—		7,711
Other regulatory liabilities	12,260		7,606
Total regulatory liabilities	$	271,387	$	267,074

Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management (Tables)

12 Months Ended

Dec. 31, 2011

Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Abstract]

Carrying Values And Fair Values Of Financial Instruments



	Carrying Value				Fair Value
	As of December 31,
	2011		2010		2011		2010
	(In Thousands)
Fixed-rate debt	$	2,373,063	$	2,373,373	$	2,623,993	$	2,570,648
Fixed-rate debt of VIEs	275,738		308,317		306,027		341,328

Fair Value Of Assets And Liabilities



As of December 31, 2011	Level 1		Level 2		Level 3		Total
	(In Thousands)
Assets:
Energy Marketing Contracts	$	—	$	2,401	$	13,330	$	15,731
Nuclear Decommissioning Trust:
Domestic equity	—		53,186		3,931		57,117
International equity	—		22,307		—		22,307
Core bonds	—		20,171		—		20,171
High-yield bonds	—		10,969		—		10,969
Emerging market bonds	—		5,309		—		5,309
Combination debt/equity fund	—		7,251		—		7,251
Real estate securities	—		—		7,095		7,095
Cash equivalents	51		—		—		51
Total Nuclear Decommissioning Trust	51		119,193		11,026		130,270
Trading Securities:
Domestic equity	—		21,175		—		21,175
International equity	—		4,896		—		4,896
Core bonds	—		13,961		—		13,961
Cash equivalents	169		—		—		169
Total Trading Securities	169		40,032		—		40,201
Total Assets Measured at Fair Value	$	220	$	161,626	$	24,356	$	186,202

Liabilities:
Energy Marketing Contracts	$	—	$	2,475	$	3,878	$	6,353
Treasury Yield Hedges	—		34,025		—		34,025
Total Liabilities Measured at Fair Value	$	—	$	36,500	$	3,878	$	40,378

As of December 31, 2010
Assets:
Energy Marketing Contracts	$	2,432	$	6,258	$	13,787	$	22,477
Nuclear Decommissioning Trust:
Domestic equity	—		60,586		2,867		63,453
International equity	—		18,966		—		18,966
Core bonds	—		31,906		—		31,906
High-yield bonds	—		9,267		305		9,572
Real estate securities	—		—		3,049		3,049
Cash equivalents	44		—		—		44
Total Nuclear Decommissioning Trust	44		120,725		6,221		126,990
Trading Securities:
Domestic equity	—		21,207		—		21,207
International equity	—		5,128		—		5,128
Core bonds	—		13,077		—		13,077
Total Trading Securities	—		39,412		—		39,412
Treasury Yield Hedges	—		7,711		—		7,711
Total Assets Measured at Fair Value	$	2,476	$	174,106	$	20,008	$	196,590

Liabilities:
Energy Marketing Contracts	$	1,888	$	5,820	$	1,972	$	9,680

Reconciliations Of Assets And Liabilities At Fair Value



	Energy Marketing Contracts, net				Nuclear Decommissioning Trust									Net Balance
	Energy Marketing Contracts, net				Domestic Equity			High-yield Bonds			Real Estate Securities			Net Balance
	(In Thousands)
Balance as of December 31, 2010	$	11,815			$	2,867		$	305		$	3,049		$	18,036
Total realized and unrealized gains (losses) included in:
Earnings (a)	603				—			—			—			603
Regulatory assets	(1,450		)	(b)	—			—			—			(1,450		)
Regulatory liabilities	2,993			(b)	479			—			670			4,142
Purchases	(6,145		)		608			—			3,455			(2,082		)
Sales	1,022				(23		)	(305		)	(79		)	615
Settlements	614				—			—			—			614
Balance as of December 31, 2011	$	9,452			$	3,931		$	—		$	7,095		$	20,478

Balance as of December 31, 2009	$	4,310			$	2,262		$	5,741		$	3,635		$	15,948
Total realized and unrealized gains (losses) included in:
Earnings (a)	(2,585		)		—			—			—			(2,585		)
Regulatory assets	3,311			(b)	—			—			—			3,311
Regulatory liabilities	8,148			(b)	16			367			(586		)	7,945
Purchases, issuances and settlements, net	(1,369		)		589			(5,803		)	—			(6,583		)
Balance as of December 31, 2010	$	11,815			$	2,867		$	305		$	3,049		$	18,036

Unrealized Gains And Losses On Financial Statements



	Year Ended December 31, 2011
	Energy Marketing Contracts, net				Nuclear Decommissioning Trust
	Energy Marketing Contracts, net				Domestic Equity		High-yield Bonds			Real Estate Securities			Net Balance
	(In Thousands)
Total unrealized gains (losses) included in:
Earnings (a)	$	(898	)		$	—	$	—		$	—		$	(898	)
Regulatory assets	(747		)	(b)	—		—			—			(747		)
Regulatory liabilities	1,736			(b)	456		—			591			2,783
Total	$	91			$	456	$	—		$	591		$	1,138

	Year Ended December 31, 2010
Total unrealized gains (losses) included in:
Earnings (a)	$	(1,441	)		$	—	$	—		$	—		$	(1,441	)
Regulatory assets	180			(b)	—		—			—			180
Regulatory liabilities	2,633			(b)	23		(31		)	(586		)	2,039
Total	$	1,372			$	23	$	(31	)	$	(586	)	$	778

Investments In Financial Instruments



	As of December 31, 2011				As of December 31, 2010				As of December 31, 2011
	Fair Value		Unfunded Commitments		Fair Value		Unfunded Commitments		Redemption Frequency	Length of Settlement
	(In thousands)
Nuclear Decommissioning Trust:
Domestic equity	$	3,931	$	1,914	$	2,867	$	2,523	(a)	(a)
High-yield bonds	—		—		305		—		(b)	(b)
Real estate securities	7,095		—		3,049		—		(c)	(c)
Total Nuclear Decommissioning Trust	$	11,026	$	1,914	$	6,221	$	2,523

Trading Securities:
Domestic equity	$	21,175	$	—	$	21,207	$	—	Upon Notice	1 day
International equity	4,896		—		5,128		—		Upon Notice	1 day
Core bonds	13,961		—		13,077		—		Upon Notice	1 day
Total Trading Securities	40,032		—		39,412		—
Total	$	51,058	$	1,914	$	45,633	$	2,523

Fair Value Of Commodity Derivative Instruments



Commodity Derivatives Not Designated as Hedging Instruments as of December 31, 2011
Asset Derivatives			Liability Derivatives
Balance Sheet Location	Fair Value		Balance Sheet Location	Fair Value
	(In Thousands)			(In Thousands)
Current assets:			Current liabilities:
Energy marketing contracts	$	8,180	Energy marketing contracts	$	6,353
Other assets:
Other	7,551
Total	$	15,731

Commodity Derivatives Not Designated as Hedging Instruments as of December 31, 2010
Asset Derivatives			Liability Derivatives
Balance Sheet Location	Fair Value		Balance Sheet Location	Fair Value
	(In Thousands)			(In Thousands)
Current assets:			Current liabilities:
Energy marketing contracts	$	13,005	Energy marketing contracts	$	9,670
Other assets:			Long-term liabilities:
Other	9,472		Other	10
Total	$	22,477	Total	$	9,680

Changes In The Fair Value Of Commodity Derivative Instruments



	Year Ended December 31, 2011					Year Ended December 31, 2010
Location	Net Gain Recognized		Net Loss Recognized			Net Gain Recognized
	(In Thousands)
Revenues increase	$	1,569	$	—		$	712
Regulatory assets increase (decrease)	—		374			(7,604		)
Regulatory liabilities (decrease) increase	—		(1,623		)	1,799

Energy Related Products Contracts



		Net Quantity as of
	Unit of Measure	December 31, 2011	December 31, 2010
Electricity	MWh	1,834,253	2,791,966
Natural Gas	MMBtu	1,467,500	1,150,000

Tabular disclosure of the fair value measurement of assets using significant unobservable inputs (Level 3), a reconciliation of the beginning and ending balances, separately presenting changes during the period attributable to the following: (1) total gains or losses for the period (realized and unrealized), segregating those gains or losses included in earnings (or changes in net assets) and gains or losses recognized in other comprehensive income, and a description of where those gains or losses included in earnings (or changes in net assets) are reported in the statement of income (or activities); (2) purchases, sales, issuances, and settlements (each type disclosed separately); and (3) transfers in and transfers out of Level 3 (for example, transfers due to changes in the observability of significant inputs), by class of asset.

+ References+ Details

Tabular disclosure of the location and amount of gains and losses reported in the statement of financial performance, or when applicable, the statement of financial position. For example, (a) gains and losses recognized in the income statement on derivative instruments designated and qualifying as hedging instruments in fair value hedges and related hedged items designated and qualifying in fair value hedges and (b) gains and losses initially recognized in other comprehensive income on derivative instruments designated and qualifying as cash flow hedges.

+ References+ Details

Tabular disclosure of the location and fair value amounts of derivative instruments (and nonderivative instruments that are designated and qualify as hedging instruments) reported in the statement of financial position.

+ References+ Details

Costs And Fair Values Of Investments

This item represents the disclosure regarding the investments in certain entities that calculate net asset value per share that enables users to understand the nature and risks of the investments and whether the investments are probable of being sold at amounts different from net asset value per share. Such disclosure may include (1) the fair value of the investments in the major category, and a description of the significant investment strategies of the investee(s) in the major category; (2) for each major category of investment that includes investments that can never be redeemed with the investees, but the reporting entity receives distributions through the liquidation of the underlying assets of the investees, the reporting entity's estimate of the period of time over which the underlying assets are expected to be liquidated by the investees; (3) the amount of the entity's unfunded commitments related to investments in the major category; (4) a general description of the terms and conditions upon which the investor may redeem investments in the major category; (5) the circumstances in which an otherwise redeemable investment in the major category might not be redeemable; (6) for those otherwise redeemable investments that are restricted from redemption as of the reporting entity's measurement date, the entity's best estimate of when the restriction from redemption might lapse; if an estimate cannot be made, the entity shall disclose that fact and how long the restriction has been in effect; (7) any other significant restriction on the ability to sell investments in the major category at the measurement date; (8) total fair value of held for sale investments and any remaining actions required to complete the sale when the reporting entity determines that it is probable that it will sell the investments for an amount different from net asset value per share; and (9) disclosure of an entity's plans to sell and any remaining actions required to complete the sale when the entity intends to sell a group of investments, but the individual investments to be sold have not been identified.

+ References+ Details

Financial Investments (Tables)

12 Months Ended

Dec. 31, 2011

Investments [Abstract]



			Gross Unrealized
Security Type	Cost		Gain		Loss			Fair Value		Allocation
	(In Thousands)
As of December 31, 2011
Domestic equity	$	55,357	$	1,760	$	—		$	57,117	44	%
International equity	24,501		—		(2,194		)	22,307		17	%
Core bonds	19,771		400		—			20,171		16	%
High-yield bonds	11,046		—		(77		)	10,969		8	%
Emerging market bonds	5,301		8		—			5,309		4	%
Combination debt/equity fund	7,524		—		(273		)	7,251		6	%
Real estate securities	9,662		—		(2,567		)	7,095		5	%
Cash equivalents	51		—		—			51		<1%
Total	$	133,213	$	2,168	$	(5,111	)	$	130,270	100	%

As of December 31, 2010
Domestic equity	$	58,592	$	4,972	$	(111	)	$	63,453	50	%
International equity	17,249		1,717		—			18,966		15	%
Core bonds	32,054		—		(148		)	31,906		25	%
High-yield bonds	9,086		486		—			9,572		8	%
Real estate securities	6,207		—		(3,158		)	3,049		2	%
Cash equivalents	44		—		—			44		<1%
Total	$	123,232	$	7,175	$	(3,417	)	$	126,990	100	%

Fair Value And The Gross Unrealized Losses Of The Available-For-Sale Securities



	Less than 12 Months					12 Months or Greater					Total
	Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses			Fair Value		Gross Unrealized Losses
	(In Thousands)
As of December 31, 2011
International equity	22,307		(2,194		)	—		—			22,307		(2,194		)
High-yield bonds	10,969		(77		)	—		—			10,969		(77		)
Combination debt/equity fund	7,251		(273		)	—		—			7,251		(273		)
Real estate securities	—		—			7,095		(2,567		)	7,095		(2,567		)
Total	$	40,527	$	(2,544	)	$	7,095	$	(2,567	)	$	47,622	$	(5,111	)

As of December 31, 2010
Domestic equity	$	2,867	$	(111	)	$	—	$	—		$	2,867	$	(111	)
Core bonds	31,906		(148		)	—		—			31,906		(148		)
Real estate securities	—		—			3,049		(3,158		)	3,049		(3,158		)
Total	$	34,773	$	(259	)	$	3,049	$	(3,158	)	$	37,822	$	(3,417	)

Property, Plant And Equipment (Tables)

12 Months Ended

Dec. 31, 2011

Public Utility, Property, Plant and Equipment [Line Items]

Schedule of Public Utility Property, Plant, and Equipment

The following is a summary of our property, plant and equipment balance.



	As of December 31,
	2011			2010
	(In Thousands)

Electric plant in service	$	8,703,278		$	8,254,884
Electric plant acquisition adjustment	802,318			802,318
Accumulated depreciation	(3,703,372		)	(3,563,566		)
	5,802,224			5,493,636
Construction work in progress	534,003			392,701
Nuclear fuel, net	75,695			78,102
Net property, plant and equipment	$	6,411,922		$	5,964,439

Variable Interest Entity [Member]

Public Utility, Property, Plant and Equipment [Line Items]

Schedule of Public Utility Property, Plant, and Equipment

The following is a summary of property, plant and equipment of VIEs.



	As of December 31,
	2011			2010
	(In Thousands)

Electric plant of VIEs	$	543,548		$	543,593
Accumulated depreciation of VIEs	(210,054		)	(198,556		)
Net property, plant and equipment of VIEs	$	333,494		$	345,037

Joint Ownership of Utility Plants Joint Ownership of Utility Plants (Tables)

12 Months Ended

Dec. 31, 2011

Jointly Owned Utility Plant, Net Ownership Amount [Abstract]

Schedule of Jointly Owned Utility Plants

Information relative to our ownership interests in these facilities as of December 31, 2011, is shown in the table below.



Plant	In-Service Dates	Investment		Accumulated Depreciation		Construction Work in Progress		Net MW	Ownership Percentage
		(Dollars in Thousands)
La Cygne unit 1 (a)	June 1973	$	332,862	$	148,890	$	68,724	368	50
JEC unit 1 (a)	July 1978	488,180		207,206		49,755		666	92
JEC unit 2 (a)	May 1980	508,327		186,660		—		667	92
JEC unit 3 (a)	May 1983	677,277		268,909		6,770		672	92
Wolf Creek (b)	Sept. 1985	1,515,165		732,651		37,740		547	47
State Line (c)	June 2001	112,024		45,841		1,579		201	40
Total		$	3,633,835	$	1,590,157	$	164,568	3,121

_______________


(a)	Jointly owned with KCPL. Our 8% leasehold interest in JEC that is consolidated as a VIE is reflected in the net megawatts (MW) and ownership percentage provided above, but not in the other amounts in the table.


(b)	Jointly owned with KCPL and Kansas Electric Power Cooperative, Inc.

Short-term Debt Additional Information

Tabular disclosure of proportionate interests in jointly owned utility plants. Includes the amount of plants in service, the accumulated provision for depreciation (if available), the amount of plants under construction, and the proportionate share. The amounts presented may be further subdivided to show amounts applicable to plant subcategories (for example, production, transmission, distribution). Includes statements that the amounts represent the utility's share in each joint plant and that it must provide its own financing. Information concerning two or more generating plants on the same site may be combined. States that the utility's share of direct expenses of the joint plants is included in the corresponding operating expenses on its income statement (for example, fuel, maintenance of plant, other operating expense). If the share of direct expenses is charged to purchased power, then disclose the amount so charged and the proportionate amounts charged to specific operating expenses on the records maintained for the joint plants.

+ References+ Details

Short-Term Debt (Tables)

12 Months Ended

Dec. 31, 2011

Debt Disclosure [Abstract]

Additional information regarding our short-term debt is as follows.



	As of December 31,
	2011			2010
	(Dollars in Thousands)

Weighted average short-term debt outstanding during the year	$	362,946		$	213,041
Weighted daily average interest rates during the year, excluding fees	0.82		%	0.63		%

Long-Term Debt (Tables)

12 Months Ended

Dec. 31, 2011

Long-term Debt, Unclassified [Abstract]

Long-term Debt Outstanding

The following table summarizes our long-term debt outstanding.



	As of December 31,
	2011			2010
	(In Thousands)
Westar Energy
First mortgage bond series:
6.00% due 2014	$	250,000		$	250,000
5.15% due 2017	125,000			125,000
5.95% due 2035	125,000			125,000
5.10% due 2020	250,000			250,000
5.875% due 2036	150,000			150,000
6.10% due 2047	150,000			150,000
8.625% due 2018	300,000			300,000
	1,350,000			1,350,000
Pollution control bond series:
Variable due 2032, 0.22% as of December 31, 2011; 0.60% as of December 31, 2010	45,000			45,000
Variable due 2032, 0.24% as of December 31, 2011; 0.54% as of December 31, 2010	30,500			30,500
5.00% due 2033	57,245			57,530
	132,745			133,030
Other long-term debt:
4.36% equipment financing loan due 2011	—			61

KGE
First mortgage bond series:
6.53% due 2037	175,000			175,000
6.15% due 2023	50,000			50,000
6.64% due 2038	100,000			100,000
6.70% due 2019	300,000			300,000
	625,000			625,000
Pollution control bond series:
5.10% due 2023	13,318			13,343
Variable due 2027, 0.28% as of December 31, 2011; 0.54% as of December 31, 2010	21,940			21,940
5.30% due 2031	108,600			108,600
5.30% due 2031	18,900			18,900
Variable due 2032, 0.28% as of December 31, 2011; 0.54% as of December 31, 2010	14,500			14,500
Variable due 2032, 0.28% as of December 31, 2011; 0.54% as of December 31, 2010	10,000			10,000
4.85% due 2031	50,000			50,000
5.60% due 2031	50,000			50,000
6.00% due 2031	50,000			50,000
5.00% due 2031	50,000			50,000
	387,258			387,283

Total long-term debt	2,495,003			2,495,374
Unamortized debt discount (a)	(3,894		)	(4,442		)
Long-term debt due within one year	—			(61		)
Long-term debt, net	$	2,491,109		$	2,490,871

Variable Interest Entities
7.77% due 2013 (b)	$	2,583		$	5,095
6.99% due 2014 (b)	2,094			3,237
5.92 % due 2019 (b)	22,748			31,171
5.647% due 2021 (b)	248,313			266,393
Total long-term debt of variable interest entities	275,738			305,896
Unamortized debt premium (a)	1,659			2,421
Long-term debt of variable interest entities due within one year	(28,114		)	(30,155		)
Long-term debt of variable interest entities, net	$	249,283		$	278,162

_______________

(a) We amortize debt discounts and premiums to interest expense over the term of the respective issues.

(b) Portions of our payments related to this debt reduce the principal balances each year until maturity.

Schedule of Maturities of Long-term Debt

The principal amounts of our long-term debt maturities as of December 31, 2011, are as follows.



Year	Long-term debt		Long-term debt of VIEs
	(In Thousands)
2012	$	—	$	28,114
2013	—		25,941
2014	250,000		27,479
2015	—		27,933
2016	—		28,309
Thereafter	2,245,003		137,962
Total maturities	$	2,495,003	$	275,738

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

Income tax expense is comprised of the following components

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+ Details

Taxes (Tables)

12 Months Ended

Dec. 31, 2011

Income Tax Disclosure [Abstract]

Income tax expense is comprised of the following components.



	Year Ended December 31,
	2011			2010			2009
	(In Thousands)
Income Tax Expense (Benefit) from Continuing Operations:
Current income taxes:
Federal	$	(8,575	)	$	(32,107	)	$	2,428
State	196			(3,030		)	9,975
Deferred income taxes:
Federal	93,089			102,568			46,148
State	21,337			20,305			3,003
Investment tax credit amortization	(2,703		)	(2,704		)	(2,704		)
Income tax expense from continuing operations	$	103,344		$	85,032		$	58,850

Income Tax Expense (Benefit) from Discontinued Operations:
Current income taxes:
Federal	$	—		$	—		$	(25,528	)
State	—			—			(10,418		)
Deferred income taxes:
Federal	—			—			(20,549		)
Income tax expense from discontinued operations	$	—		$	—		$	(56,495	)

Total income tax expense	$	103,344		$	85,032		$	2,355

Deferred tax assets and liabilities

Deferred tax assets and liabilities are reflected on our consolidated balance sheets as follows.



	As of December 31,
	2011		2010
	(In Thousands)
Current deferred tax assets	$	394	$	30,248
Non-current deferred tax liabilities	1,110,463		1,102,625
Net deferred tax liabilities	$	1,110,069	$	1,072,377

The tax effect of the temporary differences and carryforwards that comprise our deferred tax assets and deferred tax liabilities are summarized in the following table.



	As of December 31,
	2011		2010
	(In Thousands)
Deferred tax assets:
Deferred employee benefit costs	$	202,687	$	155,400
Business tax credit carryforward (a)	159,163		134,629
Net operating loss carryforward (b)	84,365		—
Deferred regulatory gain on sale-leaseback	42,962		45,381
Deferred state income taxes	42,209		14,215
Alternative minimum tax carryforward (c)	36,471		34,270
Deferred compensation	28,286		40,401
Accrued liabilities	16,912		35,714
Disallowed costs	12,717		13,357
Capital loss carryforward (d)	12,554		3,527
Other	13,031		33,577
Total gross deferred tax assets	651,357		510,471
Less: Valuation allowance (e)	13,712		59,415
Deferred tax assets	$	637,645	$	451,056

Deferred tax liabilities:
Accelerated depreciation	$	1,088,727	$	920,229
Deferred employee benefit costs	202,687		161,035
Acquisition premium	187,934		195,947
Amounts due from customers for future income taxes, net	168,804		172,181
Deferred state income taxes	39,512		16,577
Debt reacquisition costs	21,683		23,864
Pension expense tracker	14,600		8,446
Storm costs	10,176		13,733
Other	13,591		11,421
Total deferred tax liabilities	$	1,747,714	$	1,523,433

Net deferred tax liabilities	$	1,110,069	$	1,072,377

_______________

(a)


(b)	As of December 31, 2011, we had a federal net operating loss carryforward of $206.6 million, which is available to offset federal taxable income. The net operating losses will expire in 2030 and 2031.


(c)	As of December 31, 2011, we had available an alternative minimum tax credit carryforward of $36.5 million, which has an unlimited carryforward period.


(d)	As of December 31, 2011, we had an unused capital loss carryforward of $31.7 million that is available to offset future capital gains. The capital losses will expire beginning in 2013 and ending in 2016.

(e)

The difference between the effective income tax rates and the federal statutory income tax rates are as follows



	For the Year Ended December 31,
	2011		2010		2009
Statutory federal income tax rate from continuing operations	35.0	%	35.0	%	35.0	%
Effect of:
Corporate-owned life insurance policies	(4.5	)	(6.1	)	(8.2	)
State income taxes	4.1		3.8		4.3
Production tax credits	(2.9	)	(3.4	)	(3.0	)
Accelerated depreciation flow through and amortization	1.8		2.6		3.7
Amortization of federal investment tax credits	(0.8	)	(0.9	)	(1.4	)
AFUDC equity	(0.6	)	(0.4	)	(0.9	)
Capital loss utilization	(0.5	)	(0.7	)	(0.4	)
Liability for unrecognized income tax benefits	—		(0.2	)	0.2
Other	(1.2	)	(0.7	)	0.1
Effective income tax rate from continuing operations	30.4	%	29.0	%	29.4	%

A reconciliation of the beginning and ending amounts of unrecognized income tax benefits is as follows

A reconciliation of the beginning and ending amounts of unrecognized income tax benefits is as follows:



	2011			2010			2009
	(In Thousands)
Liability for unrecognized income tax benefits as of January 1	$	1,888		$	8,357		$	38,980
Additions based on tax positions related to the current year	967			608			2,254
Additions for tax positions of prior years	939			2,323			—
Reductions for tax positions of prior years	(563		)	(1,241		)	(25,722		)
Settlements	(748		)	(8,159		)	(7,155		)
Liability for unrecognized income tax benefits as of December 31	$	2,483		$	1,888		$	8,357

Tabular disclosure of tax positions taken in the tax returns filed or to be filed for which it is more likely than not that the tax position will not be sustained upon examination by taxing authorities (i.e., uncertain tax positions) and other types of income tax contingencies, including: (1) the policy on classification of interest and penalties; (2) a tabular reconciliation of the total amounts of unrecognized tax benefits at the beginning and end of the period; the total amount(s) of: (3) unrecognized tax benefits that, if recognized, would affect the effective tax rate, and (4) interest and penalties recognized in each of the income statement and balance sheet; (5) for positions for which it is reasonably possible that the total amounts unrecognized will significantly change within 12 months of the reporting date the: (i) nature of the uncertainty, (ii) nature of the event that could occur that would cause the change, and (iii) an estimate of the range of the reasonably possible change or a statement that an estimate of the range cannot be made; and (6) a description of tax years that remain subject to examination by major tax jurisdictions.

+ References+ Details

Employee Benefit Plans (Tables)

12 Months Ended

Dec. 31, 2011

Schedule Of Benefit Obligations In Excess Of Fair Value Of Plan Assets And Assumptions Used For Benefit Obligation



	Pension Benefits						Post-retirement Benefits
As of December 31,	2011			2010			2011			2010
	(Dollars in Thousands)
Pension Plans With a Projected Benefit Obligation In Excess of Plan Assets:
Projected benefit obligation	$	876,308		$	747,460		$	—		$	—
Fair value of plan assets	481,077			432,233			—			—

Pension Plans With an Accumulated Benefit Obligation In Excess of Plan Assets:
Accumulated benefit obligation	$	750,263		$	635,541		—			—
Fair value of plan assets	481,077			432,233			—			—

Post-retirement Plans With an Accumulated Post-retirement Benefit Obligation In Excess of Plan Assets:
Accumulated post-retirement benefit obligation	—			—			$	150,078		$	137,759
Fair value of plan assets	—			—			91,858			86,984

Weighted-Average Actuarial Assumptions used to Determine Net Periodic Benefit Obligation:
Discount rate	4.50		%	5.35		%	4.25		%	5.00		%
Compensation rate increase	4.00		%	4.00		%	—			—

Net Periodic Costs For Pension And Post-Retirement Benefit Plans

The following tables summarize the status of our pension and post-retirement benefit plans.



	Pension Benefits						Post-retirement Benefits
As of December 31,	2011			2010			2011			2010
	(In Thousands)
Change in Benefit Obligation:
Benefit obligation, beginning of year	$	747,460		$	662,495		$	137,759		$	128,998
Service cost	16,076			13,926			1,803			1,526
Interest cost	40,045			39,391			6,793			7,083
Plan participants’ contributions	—			—			3,390			3,292
Benefits paid	(31,107		)	(29,690		)	(10,114		)	(11,090		)
Actuarial losses (gains)	94,161			60,662			5,246			7,950
Amendments	—			676			4,451			—
Other (a)	9,673			—			750			—
Benefit obligation, end of year	$	876,308		$	747,460		$	150,078		$	137,759

Change in Plan Assets:
Fair value of plan assets, beginning of year	$	432,233		$	404,243		$	86,984		$	74,114
Actual return on plan assets	27,819			33,359			(174		)	9,849
Employer contributions	50,000			22,400			10,793			10,512
Plan participants’ contributions	—			—			3,244			3,147
Part D reimbursements	—			—			—			317
Benefits paid	(28,975		)	(27,769		)	(9,739		)	(10,955		)
Other (a)	—			—			750			—
Fair value of plan assets, end of year	$	481,077		$	432,233		$	91,858		$	86,984

Funded status, end of year	$	(395,231	)	$	(315,227	)	$	(58,220	)	$	(50,775	)

Amounts Recognized in the Balance Sheets Consist of:
Current liability	$	(2,741	)	$	(2,030	)	$	(115	)	$	(91	)
Noncurrent liability	(392,490		)	(313,197		)	(58,105		)	(50,684		)
Net amount recognized	$	(395,231	)	$	(315,227	)	$	(58,220	)	$	(50,775	)

Amounts Recognized in Regulatory Assets Consist of:
Net actuarial loss	$	397,691		$	323,924		$	18,178		$	8,458
Prior service cost	4,606			5,819			18,991			17,065
Transition obligation	—			—			4,236			8,148
Net amount recognized	$	402,297		$	329,743		$	41,405		$	33,671

_______________


(a)	Other includes the $9.7 million reclassification of a contractual obligation related to the legal settlement with a former executive officer and $0.8 million of proceeds received as a result of the Early Retiree Reinsurance Program.

Schedule Of Amounts To Be Amortized From Regulatory Assets To Net Periodic Cost

We estimate that we will amortize the following amounts from regulatory assets into net periodic cost in 2012.



	Pension Benefits		Post-retirement Benefits
	(In Thousands)

Actuarial loss	$	32,782	$	1,509
Prior service cost	613		2,524
Transition obligation	—		3,911
Total	$	33,395	$	7,944

Schedule of Health Care Cost Trend Rates

For measurement purposes, the assumed annual health care cost growth rates were as follows.



	As of December 31,
	2011	2010

Health care cost trend rate assumed for next year	8.0%	8.0%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate)	5.0%	5.0%

Year that the rate reaches the ultimate trend rate	2018	2018

Schedule of Effect of One-Percentage-Point Change in Assumed Health Care Cost Trend Rates

The health care cost trend rate affects the projected benefit obligation. A 1% change in assumed health care cost growth rates would have effects shown in the following table.



	One-Percentage- Point Increase		One-Percentage- Point Decrease
	(In Thousands)

Effect on total of service and interest cost	$	69	$	(65	)
Effect on post-retirement benefit obligation	1,465		(1,362		)

Schedule of Effect of Significant Unobservable Inputs, Changes in Plan Assets

The following table provides a reconciliation of pension plan assets measured at fair value using significant level 3 inputs for the years ended December 31, 2011 and 2010.



	Domestic Equity		High-yield Bonds			Real Estate Securities			Alternative Funds			Net Balance
	(In Thousands)

Balance as of December 31, 2010	$	11,575	$	1,200		$	16,411		$	25,764		$	54,950
Actual gain (loss) on plan assets:
Relating to assets still held at the reporting date	1,910		—			2,652			(48		)	4,514
Relating to assets sold during the period	—		—			(49		)	—			(49		)
Purchases, issuances and settlements, net	1,890		(1,200		)	(166		)	15,000			15,524
Balance as of December 31, 2011	$	15,375	$	—		$	18,848		$	40,716		$	74,939

Balance as of December 31, 2009	$	9,310	$	22,519		$	14,518		$	—		$	46,347
Actual gain (loss) on plan assets:
Relating to assets still held at the reporting date	75		(3,963		)	2,117			864			(907		)
Relating to assets sold during the period	—		4,325			(77		)	—			4,248
Purchases, issuances and settlements, net	2,190		(21,681		)	(147		)	24,900			5,262
Balance as of December 31, 2010	$	11,575	$	1,200		$	16,411		$	25,764		$	54,950

Schedule of Expected Benefit Payments

Cash Flows

The following table shows the expected cash flows for our pension and post-retirement benefit plans for future years.



Expected Cash Flows	Pension Benefits						Post-retirement Benefits
	To/(From) Trust			To/(From) Company Assets			To/(From) Trust			To/(From) Company Assets
	(In Millions)
Expected contributions:
2012	$	57.4		$	2.7		$	10.8		$	0.1

Expected benefit payments:
2012	$	(29.3	)	$	(2.7	)	$	(7.9	)	$	(0.1	)
2013	(31.1		)	(2.7		)	(8.3		)	(0.1		)
2014	(33.1		)	(2.8		)	(8.7		)	(0.1		)
2015	(35.1		)	(2.8		)	(9.3		)	(0.1		)
2016	(37.8		)	(2.8		)	(9.6		)	(0.1		)
2017 - 2021	(231.9		)	(13.2		)	(51.3		)	(0.7		)

Schedule of Compensation Expense and Income Tax Benefits Related to Stock Compensation Arrangements

The table below shows compensation expense and income tax benefits related to stock-based compensation arrangements that are included in our net income.



	Year Ended December 31,
	2011		2010		2009
	(In Thousands)

Compensation expense	$	8,367	$	11,321	$	5,080
Income tax benefits related to stock-based compensation arrangements	3,309		4,481		2,011

Other Postretirement Benefit Plans, Defined Benefit [Member]

Schedule of Allocation of Plan Assets

The following table provides the fair value of our post-retirement benefit plan assets and the corresponding level of hierarchy as of December 31, 2011 and 2010.



As of December 31, 2011	Level 1		Level 2		Level 3		Total
	(In Thousands)
Assets:
Domestic equity	$	—	$	47,411	$	—	$	47,411
International equity	—		11,500		—		11,500
Core bonds	—		32,192		—		32,192
Cash equivalents	—		755		—		755
Total Assets Measured at Fair Value	$	—	$	91,858	$	—	$	91,858

As of December 31, 2010

Assets:
Domestic equity	$	—	$	45,766	$	—	$	45,766
International equity	—		11,280		—		11,280
Core bonds	—		29,938		—		29,938
Total Assets Measured at Fair Value	$	—	$	86,984	$	—	$	86,984

Pension Benefits [Member]

Schedule of Allocation of Plan Assets

The following table provides the fair value of our pension plan assets and the corresponding level of hierarchy as of December 31, 2011 and 2010.



As of December 31, 2011	Level 1		Level 2		Level 3		Total
	(In Thousands)
Assets:
Domestic equity	$	—	$	121,364	$	15,375	$	136,739
International equity	—		53,943		—		53,943
Core bonds	—		142,700		—		142,700
High-yield bonds	—		38,380		—		38,380
Combination debt/equity fund	—		47,151		—		47,151
Real estate securities	—		—		18,848		18,848
Alternative funds	—		—		40,716		40,716
Cash equivalents	—		2,600		—		2,600
Total Assets Measured at Fair Value	$	—	$	406,138	$	74,939	$	481,077

As of December 31, 2010

Assets:
Domestic equity	$	—	$	117,250	$	11,575	$	128,825
International equity	—		44,834		—		44,834
Core bonds	—		183,361		—		183,361
High-yield bonds	—		28,819		1,200		30,019
Real estate securities	—		—		16,411		16,411
Alternative funds	—		—		25,764		25,764
Cash equivalents	—		3,019		—		3,019
Total Assets Measured at Fair Value	$	—	$	377,283	$	54,950	$	432,233

RSU Awards With Performance Measures [Member]

Schedule of Share-based Compensation, Restricted Stock Units Award Activity, Service Requirements

During the years ended December 31, 2011, 2010 and 2009, our RSU activity for awards with performance measures was as follows:



	As of December 31,
	2011				2010				2009
	Shares		Weighted- Average Grant Date Fair Value		Shares		Weighted- Average Grant Date Fair Value		Shares	Weighted- Average Grant Date Fair Value
	(Shares In Thousands)

Nonvested balance, beginning of year	348.4		$	24.98	—		$	—	—	$	—
Granted	244.4		31.26		366.0		24.96		—	—
Vested	(119.5	)	24.12		(4.5	)	23.32		—	—
Forfeited	(149.1	)	28.72		(13.1	)	24.99		—	—
Nonvested balance, end of year	324.2		28.31		348.4		24.98		—	—

RSU Awards With Only Service Requirements [Member]

Schedule of Share-based Compensation, Restricted Stock Units Award Activity, Service Requirements

During the years ended December 31, 2011, 2010 and 2009, our RSU activity for awards with only service requirements was as follows:



	As of December 31,
	2011				2010				2009
	Shares		Weighted- Average Grant Date Fair Value		Shares		Weighted- Average Grant Date Fair Value		Shares		Weighted- Average Grant Date Fair Value
	(Shares In Thousands)

Nonvested balance, beginning of year	600.4		$	21.50	368.8		$	21.98	727.4		$	20.86
Granted	284.1		26.30		366.4		22.14		83.5		18.33
Vested	(187.3	)	23.50		(118.1	)	24.81		(439.0	)	19.43
Forfeited	(328.7	)	24.37		(16.7	)	22.32		(3.1	)	20.63
Nonvested balance, end of year	368.5		23.83		600.4		21.50		368.8		21.98

Wolf Creek Employee Benefit Plans (Tables)

12 Months Ended

Dec. 31, 2011

Wolf Creek Interim Pension And Post-Retirement Benefit Disclosure [Line Items]

Schedule of Net Periodic Benefit Cost Not yet Recognized

Following is additional information regarding our pension and post-retirement benefit plans.



	Pension Benefits									Post-retirement Benefits
Year Ended December 31,	2011			2010			2009			2011			2010			2009
	(Dollars in Thousands)
Components of Net Periodic Cost (Benefit):
Service cost	$	16,076		$	13,926		$	12,882		$	1,803		$	1,526		$	1,529
Interest cost	40,045			39,391			38,162			6,793			7,083			6,917
Expected return on plan assets	(31,087		)	(38,384		)	(37,826		)	(5,002		)	(5,197		)	(4,756		)
Amortization of unrecognized:
Transition obligation, net	—			—			—			3,911			3,912			3,912
Prior service costs	1,213			2,729			2,668			2,524			2,154			1,580
Actuarial loss/(gain), net	23,659			17,183			14,263			702			321			(38		)
Net periodic cost before regulatory adjustment	49,906			34,845			30,149			10,731			9,799			9,144
Regulatory adjustment	(22,098		)	(12,167		)	(9,188		)	1,344			1,868			2,280
Net periodic cost	$	27,808		$	22,678		$	20,961		$	12,075		$	11,667		$	11,424

Other Changes in Plan Assets and Benefit Obligations Recognized in Regulatory Assets:
Current year actuarial (gain)/loss	$	97,429		$	65,690		$	(34,610	)	$	10,421		$	3,298		$	(26,205	)
Amortization of actuarial (loss)/gain	(23,659		)	(17,183		)	(14,263		)	(702		)	(321		)	38
Current year prior service cost	—			676			48			4,451			—			6,672
Amortization of prior service costs	(1,213		)	(2,729		)	(2,668		)	(2,524		)	(2,154		)	(1,580		)
Current year offset of initial transition asset due to plan change	—			—			—			—			—			(76		)
Amortization of transition obligation	—			—			—			(3,911		)	(3,912		)	(3,912		)
Total recognized in regulatory assets	$	72,557		$	46,454		$	(51,493	)	$	7,735		$	(3,089	)	$	(25,063	)

Total recognized in net periodic cost and regulatory assets	$	100,365		$	69,132		$	(30,532	)	$	19,810		$	8,578		$	(13,639	)

Weighted-Average Actuarial Assumptions used to Determine Net Periodic Cost (Benefit):
Discount rate	5.35		%	5.95		%	6.10		%	5.00		%	5.65		%	6.05		%
Expected long-term return on plan assets	6.50		%	8.25		%	8.25		%	6.00		%	7.75		%	7.75		%
Compensation rate increase	4.00		%	4.00		%	4.00		%	—			—			—

Schedule Of Amounts To Be Amortized From Regulatory Assets To Net Periodic Cost

We estimate that we will amortize the following amounts from regulatory assets into net periodic cost in 2012.



	Pension Benefits		Post-retirement Benefits
	(In Thousands)

Actuarial loss	$	32,782	$	1,509
Prior service cost	613		2,524
Transition obligation	—		3,911
Total	$	33,395	$	7,944

Schedule of Health Care Cost Trend Rates

For measurement purposes, the assumed annual health care cost growth rates were as follows.



	As of December 31,
	2011	2010

Health care cost trend rate assumed for next year	8.0%	8.0%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate)	5.0%	5.0%

Year that the rate reaches the ultimate trend rate	2018	2018

Schedule of Effect of One-Percentage-Point Change in Assumed Health Care Cost Trend Rates

The health care cost trend rate affects the projected benefit obligation. A 1% change in assumed health care cost growth rates would have effects shown in the following table.



	One-Percentage- Point Increase		One-Percentage- Point Decrease
	(In Thousands)

Effect on total of service and interest cost	$	69	$	(65	)
Effect on post-retirement benefit obligation	1,465		(1,362		)

Schedule of Effect of Significant Unobservable Inputs, Changes in Plan Assets

The following table provides a reconciliation of pension plan assets measured at fair value using significant level 3 inputs for the years ended December 31, 2011 and 2010.



	Domestic Equity		High-yield Bonds			Real Estate Securities			Alternative Funds			Net Balance
	(In Thousands)

Balance as of December 31, 2010	$	11,575	$	1,200		$	16,411		$	25,764		$	54,950
Actual gain (loss) on plan assets:
Relating to assets still held at the reporting date	1,910		—			2,652			(48		)	4,514
Relating to assets sold during the period	—		—			(49		)	—			(49		)
Purchases, issuances and settlements, net	1,890		(1,200		)	(166		)	15,000			15,524
Balance as of December 31, 2011	$	15,375	$	—		$	18,848		$	40,716		$	74,939

Balance as of December 31, 2009	$	9,310	$	22,519		$	14,518		$	—		$	46,347
Actual gain (loss) on plan assets:
Relating to assets still held at the reporting date	75		(3,963		)	2,117			864			(907		)
Relating to assets sold during the period	—		4,325			(77		)	—			4,248
Purchases, issuances and settlements, net	2,190		(21,681		)	(147		)	24,900			5,262
Balance as of December 31, 2010	$	11,575	$	1,200		$	16,411		$	25,764		$	54,950

Schedule of Expected Benefit Payments

Cash Flows

The following table shows the expected cash flows for our pension and post-retirement benefit plans for future years.



Expected Cash Flows	Pension Benefits						Post-retirement Benefits
	To/(From) Trust			To/(From) Company Assets			To/(From) Trust			To/(From) Company Assets
	(In Millions)
Expected contributions:
2012	$	57.4		$	2.7		$	10.8		$	0.1

Expected benefit payments:
2012	$	(29.3	)	$	(2.7	)	$	(7.9	)	$	(0.1	)
2013	(31.1		)	(2.7		)	(8.3		)	(0.1		)
2014	(33.1		)	(2.8		)	(8.7		)	(0.1		)
2015	(35.1		)	(2.8		)	(9.3		)	(0.1		)
2016	(37.8		)	(2.8		)	(9.6		)	(0.1		)
2017 - 2021	(231.9		)	(13.2		)	(51.3		)	(0.7		)

Wolf Creek [Member]

Wolf Creek Interim Pension And Post-Retirement Benefit Disclosure [Line Items]

Schedule Of Benefit Obligation Fair Value Of Plan Assets Amounts Recognized In Balance Sheet Benefit Obligations In Excess Of Fair Value Of Plan Assets And Assumptions Used For Benefit Obligation [Table Text Block]

The following tables summarize the status of KGE's 47% share of the Wolf Creek pension and post-retirement benefit plans.



	Pension Benefits						Post-retirement Benefits
As of December 31,	2011			2010			2011			2010
	(In Thousands)
Change in Benefit Obligation:
Benefit obligation, beginning of year	$	131,460		$	111,033		$	10,144		$	9,574
Service cost	4,957			4,144			165			179
Interest cost	7,370			6,941			458			519
Plan participants’ contributions	—			—			614			554
Benefits paid	(3,033		)	(2,799		)	(979		)	(1,045		)
Actuarial losses (gains)	20,642			12,141			(360		)	363
Other (a)	—			—			87			—
Benefit obligation, end of year	$	161,396		$	131,460		$	10,129		$	10,144

Change in Plan Assets:
Fair value of plan assets, beginning of year	$	76,086		$	62,516		$	—		$	—
Actual return on plan assets	(2,578		)	10,082			—			—
Employer contributions	10,009			6,044			369			—
Plan participants' contribution	—			—			614			—
Benefits paid	(2,790		)	(2,556		)	(979		)	—
Fair value of plan assets, end of year	$	80,727		$	76,086		$	4		$	—

Funded status, end of year	$	(80,669	)	$	(55,374	)	$	(10,125	)	$	(10,144	)

Amounts Recognized in the Balance Sheets Consist of:
Current liability	$	(243	)	$	(256	)	$	(609	)	$	(689	)
Noncurrent liability	(80,426		)	(55,118		)	(9,516		)	(9,455		)
Net amount recognized	$	(80,669	)	$	(55,374	)	$	(10,125	)	$	(10,144	)

Amounts Recognized in Regulatory Assets Consist of:
Net actuarial loss	$	65,273		$	39,735		$	3,208		$	3,796
Prior service cost	31			47			—			—
Transition obligation	—			52			58			115
Net amount recognized	$	65,304		$	39,834		$	3,266		$	3,911

	Pension Benefits						Post-retirement Benefits
As of December 31,	2011			2010			2011			2010
	(Dollars in Thousands)
Pension Plans With a Projected Benefit Obligation In Excess of Plan Assets:
Projected benefit obligation	$	161,396		$	131,460		$	—		$	—
Fair value of plan assets	80,727			76,086			—			—

Pension Plans With an Accumulated Benefit Obligation In Excess of Plan Assets:
Accumulated benefit obligation	$	128,633		$	106,684		$	—		$	—
Fair value of plan assets	80,727			76,086			—			—

Post-retirement Plans With an Accumulated Post-retirement Benefit Obligation In Excess of Plan Assets:
Accumulated post-retirement benefit obligation	$	—		$	—		$	10,129		$	10,144
Fair value of plan assets	—			—			4			—

Weighted-Average Actuarial Assumptions used to Determine Net Periodic Benefit Obligation:
Discount rate	4.55		%	5.45		%	4.10		%	4.90		%
Compensation rate increase	4.00		%	4.00		%	—			—

_______________


(a)	Includes proceeds received as a result of the Early Retiree Reinsurance Program.

Schedule of Net Periodic Benefit Cost Not yet Recognized

Following is additional information regarding KGE's 47% share of the Wolf Creek pension and other post-retirement benefit plans.



	Pension Benefits									Post-retirement Benefits
Year Ended December 31,	2011			2010			2009			2011			2010			2009
	(Dollars in Thousands)
Components of Net Periodic Cost (Benefit):
Service cost	$	4,957		$	4,144		$	3,643		$	165		$	179		$	188
Interest cost	7,370			6,941			6,401			458			519			538
Expected return on plan assets	(5,904		)	(5,453		)	(4,976		)	—			—			—
Amortization of unrecognized:
Transition obligation, net	52			57			57			58			58			58
Prior service costs	16			29			43			—			—			—
Actuarial loss, net	3,586			2,636			2,538			227			276			257
Net periodic cost before regulatory adjustment	10,077			8,354			7,706			908			1,032			1,041
Regulatory adjustment	(2,546		)	(1,498		)	(945		)	—			—			—
Net periodic cost	$	7,531		$	6,856		$	6,761		$	908		$	1,032		$	1,041

Other Changes in Plan Assets and Benefit Obligations Recognized in Regulatory Assets:
Current year actuarial (gain)/loss	$	29,124		$	7,514		$	(3,407	)	$	(360	)	$	363		$	708
Amortization of actuarial loss	(3,586		)	(2,636		)	(2,538		)	(227		)	(276		)	(257		)
Amortization of prior service cost	(16		)	(29		)	(43		)	—			—			—
Amortization of transition obligation	(52		)	(57		)	(57		)	(58		)	(58		)	(58		)
Total recognized in regulatory assets	$	25,470		$	4,792		$	(6,045	)	$	(645	)	$	29		$	393

Total recognized in net periodic cost and regulatory assets	$	33,001		$	11,648		$	716		$	263		$	1,061		$	1,434

Weighted-Average Actuarial Assumptions used to Determine Net Periodic Cost:
Discount rate	5.45		%	6.05		%	6.15		%	4.90		%	5.50		%	6.05		%
Expected long-term return on plan assets	7.50		%	8.00		%	8.00		%	—			—			—
Compensation rate increase	4.00		%	4.00		%	4.00		%	—			—			—

Schedule Of Amounts To Be Amortized From Regulatory Assets To Net Periodic Cost

We estimate that we will amortize the following amounts from regulatory assets into net periodic cost in 2012.



	Pension Benefits		Post-retirement Benefits
	(In Thousands)

Actuarial loss	$	5,368	$	233
Prior service cost	6		—
Transition obligation	—		58
Total	$	5,374	$	291

Schedule of Health Care Cost Trend Rates

For measurement purposes, the assumed annual health care cost growth rates were as follows.



	As of December 31,
	2011		2010

Health care cost trend rate assumed for next year	8.0	%	8.0	%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate)	5.0	%	5.0	%

Year that the rate reaches the ultimate trend rate	2018		2018

Schedule of Effect of One-Percentage-Point Change in Assumed Health Care Cost Trend Rates

The health care cost trend rate affects the projected benefit obligation. A 1% change in assumed health care cost growth rates would have effects shown in the following table.



	One-Percentage- Point Increase			One-Percentage- Point Decrease
	(In Thousands)

Effect on total of service and interest cost	$	(8	)	$	8
Effect on post-retirement benefit obligation	(107		)	103

Schedule of Allocation of Plan Assets

The following table provides the fair value of KGE's 47% share of Wolf Creek's pension plan assets and the corresponding level of hierarchy as of December 31, 2011 and 2010.



As of December 31, 2011	Level 1		Level 2		Level 3		Total
	(In Thousands)
Assets:
Domestic equity	$	30,753	$	—	$	—	$	30,753
International equity	9,953		8,070		—		18,023
Core bonds	—		17,877		—		17,877
High-yield bonds	4,102		—		—		4,102
Real estate securities	—		—		3,630		3,630
Commodities	—		4,377		—		4,377
Cash equivalents	—		1,965		—		1,965
Total Assets Measured at Fair Value	$	44,808	$	32,289	$	3,630	$	80,727

As of December 31, 2010

Assets:
Domestic equity	$	31,492	$	—	$	—	$	31,492
International equity	9,036		9,597		—		18,633
Core bonds	—		14,156		—		14,156
High-yield bonds	3,319		—		—		3,319
Real estate securities	—		—		3,160		3,160
Commodities	—		4,558		—		4,558
Cash equivalents	1		767		—		768
Total Assets Measured at Fair Value	$	43,848	$	29,078	$	3,160	$	76,086

Schedule of Effect of Significant Unobservable Inputs, Changes in Plan Assets




	Real Estate Securities
	(In Thousands)

Balance as of December 31, 2010	$	3,160
Actual gain (loss) on plan assets:
Relating to assets still held at the reporting date	500
Relating to assets sold during the period	2
Purchases, issuances and settlements, net	(32		)
Balance as of December 31, 2011	$	3,630

Balance as of December 31, 2009	$	2,416
Actual gain (loss) on plan assets:
Relating to assets still held at the reporting date	393
Relating to assets sold during the period	(2		)
Purchases, issuances and settlements, net	353
Balance as of December 31, 2010	$	3,160

Schedule of Expected Benefit Payments

The following table shows our expected cash flows for KGE's 47% share of Wolf Creek's pension and post-retirement benefit plans for future years.



Expected Cash Flows	Pension Benefits						Post-retirement Benefits
	To/(From) Trust			To/(From) Company Assets			To/(From) Trust		To/(From) Company Assets
	(In Millions)
Expected contributions:
2012	$	11.5		$	0.2		$	—	$	0.6

Expected benefit payments:
2012	$	(3.4	)	$	(0.2	)	$	—	$	(0.6	)
2013	(3.9		)	(0.2		)	—		(0.7		)
2014	(4.4		)	(0.2		)	—		(0.7		)
2015	(5.1		)	(0.2		)	—		(0.7		)
2016	(5.9		)	(0.2		)	—		(0.8		)
2017 - 2021	(43.3		)	(1.0		)	—		(4.0		)

Variable Interest Entities (Tables)

12 Months Ended

Dec. 31, 2011

Variable Interest Entities [Abstract]

Assets And Liabilities In Relation To VIEs

We have recorded the following assets and liabilities on our consolidated balance sheets related to the VIEs described above.



	As of December 31,
	2011		2010
	(In Thousands)
Assets:
Property, plant and equipment of variable interest entities, net	$	333,494	$	345,037
Regulatory assets (a)	4,915		3,963

Liabilities:
Current maturities of long-term debt of variable interest entities	$	28,114	$	30,155
Accrued interest (b)	4,448		5,064
Long-term debt of variable interest entities, net	249,283		278,162

_______________

(a) Included in long-term regulatory assets on our consolidated balance sheets.

(b) Included in accrued interest on our consolidated balance sheets.

Operating Leases, Minimum Annual Rental Payments

+ Details

Leases (Tables)

12 Months Ended

Dec. 31, 2011

Leases [Abstract]

Rental expense and estimated future commitments under operating leases are as follows.



Year Ended December 31,	Total Operating Leases
	(In Thousands)
Rental expense:
2009	$	38,096
2010 (a)	15,464
2011	17,577

Future commitments:
2012	$	16,247
2013	13,919
2014	11,820
2015	9,721
2016	8,393
Thereafter	17,520
Total future commitments	$	77,620

Assets Recorded Under Capital Leases



	As of December 31,
	2011			2010
	(In Thousands)
Vehicles	$	14,241		$	12,504
Computer equipment	1,720			5,551
Power plant	40,048			—
Accumulated amortization	(6,485		)	(8,744		)
Total capital leases	$	49,524		$	9,311

Capital Leases, Minimum Annual Rental Payments



Year Ended December 31,	Total Capital Leases
	(In Thousands)

2012	$	5,452
2013	5,200
2014	5,203
2015	4,987
2016	4,127
Thereafter	67,830
	92,799
Amounts representing imputed interest	(43,275		)
Present value of net minimum lease payments under capital leases	49,524
Less: Current portion	2,471
Total long-term obligation under capital leases	$	47,053

Quarterly Results (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2011

Quarterly Financial Information Disclosure [Abstract]

Schedule of Quarterly Financial Information

Our business is seasonal in nature and, in our opinion, comparisons between the quarters of a year do not give a true indication of overall trends and changes in operations.



2011	First		Second		Third (a)		Fourth
	(In Thousands, Except Per Share Amounts)

Revenues (b)	$	481,720	$	524,892	$	678,152	$	486,228
Net income (b)	32,957		45,525		136,392		21,306
Net income attributable to common stock (b)	31,342		43,887		134,708		19,335

Per Share Data (b):

Basic:
Earnings available	$	0.27	$	0.38	$	1.15	$	0.16

Diluted:
Earnings available	$	0.27	$	0.38	$	1.14	$	0.16

Cash dividend declared per common share	$	0.32	$	0.32	$	0.32	$	0.32
Market price per common share:
High	$	26.60	$	27.98	$	27.29	$	29.05
Low	$	25.05	$	25.58	$	22.63	$	25.02

_______________

(a)


(b)	Items are computed independently for each of the periods presented and the sum of the quarterly amounts may not equal the total for the year.



2010	First		Second		Third (a)		Fourth
	(In Thousands, Except Per Share Amounts)

Revenues (b)	$	459,830	$	495,181	$	644,437	$	456,723
Net income (b)	31,682		54,530		115,863		6,550
Net income attributable to common stock (b)	30,438		53,069		114,502		4,919

Per Share Data (b):

Basic:
Earnings available	$	0.27	$	0.47	$	1.02	$	0.04

Diluted:
Earnings available	$	0.27	$	0.47	$	1.01	$	0.04

Cash dividend declared per common share	$	0.31	$	0.31	$	0.31	$	0.31
Market price per common share:
High	$	22.78	$	23.93	$	24.64	$	25.90
Low	$	20.56	$	21.08	$	21.22	$	24.21

________________


(a)	In the third quarter of 2010, net income and net income attributable to common stock increased due principally to warmer than normal weather in our service territory. As measured by cooling degree days, the weather during the third quarter of 2010 was 20% warmer than the 20-year average.


(b)	Items are computed independently for each of the periods presented and the sum of the quarterly amounts may not equal the total for the year.

Summary Of Significant Accounting Policies (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011 M	Dec. 31, 2010	Dec. 31, 2009
Property, Plant and Equipment [Line Items]
Public Utilities, Deferred Maintenance Cost, Amortization Period	18
Average annual composite basis using group rates	3.00%	2.90%	3.00%
Unbilled revenue	$ 54,000,000	$ 53,800,000
Gain on sale of non-utility investment	(7,246,000)	0	0
Nuclear Fuel [Member]
Property, Plant and Equipment [Line Items]
Accumulated amortization	44,800,000	48,000,000
Fuel and purchased power expense	$ 24,600,000	$ 29,200,000	$ 20,100,000

Summary Of Significant Accounting Policies (Fuel Inventory And Supplies) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Public Utilities, Inventory [Line Items]
Total	$ 229,118	$ 206,867
Fuel Inventory [Member]
Public Utilities, Inventory [Line Items]
Public Utilitiy Inventory	86,408	79,938
Supplies [Member]
Public Utilities, Inventory [Line Items]
Public Utilitiy Inventory	$ 142,710	$ 126,929

Summary Of Significant Accounting Policies (Allowance For Funds Used During Construction) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Accounting Policies [Abstract]
Borrowed funds	$ 5,589	$ 4,295	$ 4,857
Equity funds	5,550	3,104	5,031
Total	$ 11,139	$ 7,399	$ 9,888
Average AFUDC rates	3.60%	2.60%	4.20%

Total increase in earnings in the period representing the cost of equity (based on assumed rate of return) and/or borrowed funds (based on interest rate) used to finance construction of regulated assets, which is expected to be recovered through rate adjustments.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 71

-Paragraph 15

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 90

-Paragraph 8

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 92

-Paragraph 8, 9, 12

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 980

-SubTopic 360

-Section 25

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6500269&loc=d3e45485-110386

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 980

-SubTopic 340

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6499975&loc=d3e44278-110382

+ Details

Summary Of Significant Accounting Policies (Depreciable Lives of PP&E) (Details)	12 Months Ended
	Dec. 31, 2011 Minimum [Member]	Dec. 31, 2010 Maximum [Member]	Dec. 31, 2011 Fossil Fuel Plant [Member] Minimum [Member]	Dec. 31, 2010 Fossil Fuel Plant [Member] Maximum [Member]	Dec. 31, 2011 Nuclear Plant [Member] Minimum [Member]	Dec. 31, 2010 Nuclear Plant [Member] Maximum [Member]	Dec. 31, 2011 Other Plant in Service [Member] Minimum [Member]	Dec. 31, 2010 Other Plant in Service [Member] Maximum [Member]
Regulatory Assets [Line Items]
Generating facilities, estimated useful life			P7Y	P78Y	P33Y	P62Y	P19Y	P20Y
Transmission facilities, estimated useful life	P15Y	P67Y
Distribution facilities, estimated useful life	P15Y	P70Y
Other, estimated useful life	P6Y	P28Y

Summary Of Significant Accounting Policies (Cash Surrender Value of Life Insurance) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Accounting Policies [Abstract]
Cash surrender value of policies	$ 1,345,443	$ 1,280,615
Borrowings against policies	(1,208,389)	(1,144,248)
Corporate-owned life insurance, net	$ 137,054	$ 136,367

Carrying amount as of the balance sheet date of amounts which could be received based on the terms of the insurance contract upon surrendering life policies owned by the entity.

+ References+ Details

This item represents the amount that could be realized under a life insurance contract or contracts owned by the Entity as of the date of the statement of financial position. Such Entity-owned life insurance policies are commonly known as corporate-owned life insurance (COLI) or bank-owned life insurance (BOLI).

+ References+ Details

Summary Of Significant Accounting Policies (Reconciliation Of Basic And Diluted EPS) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Accounting Policies [Abstract]
Income from continuing operations	$ 236,180	$ 208,624	$ 141,330
Less: Income attributable to noncontrolling interests	5,941	4,728	0
Income from continuing operations attributable to Westar Energy	230,239	203,896	141,330
Less: Preferred dividends	970	970	970
Income from continuing allocated to RSUs	772	1,259	541
Income from continuing operations attributable to common stock	$ 228,497	$ 201,667	$ 139,819
Weighted average equivalent common shares outstanding - basic	116,890,552	111,629,292	109,647,689
RSUs	188,025	140,077	0
Forward sale agreements	1,211,645	245,496	0
Employee stock options	0	59	481
Weighted average equivalent common shares outstanding - diluted	118,290,222	112,014,924	109,648,170
Basic earnings available from continuing operations	$ 1.95	$ 1.81	$ 1.28
Diluted earnings available from continuing operations	$ 1.93	$ 1.80	$ 1.28

Summary Of Significant Accounting Policies (Supplemental Cash Flow Information) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Cash Paid For (Received From)
Interest on financing activities	$ 145,570	$ 145,463	$ 144,964
Income taxes, net of refunds	(17,519)	(34,980)	(7,870)
Noncash Investing and Financing Transactions
Property, plant and equipment additions	105,435	64,423	21,614
Jeffrey Energy Center (JEC) 8% leasehold interest	0	(108,706)	0
Issuance of common stock for reinvested dividends and compensation plans	15,103	18,777	12,168
Capital lease for JEC 8% leasehold interest	0	(106,423)	0
Assets acquired through capital leases	43,011	910	2,818
Variable Interest Entity, Primary Beneficiary [Member]
Cash Paid For (Received From)
Interest on financing activities	18,167	20,191	0
Noncash Investing and Financing Transactions
Property, plant and equipment additions	0	356,964	0
Debt of VIEs	$ 0	$ 337,951	$ 0

Rate Matters And Regulation (Regulatory Assets and Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Regulatory Assets and Liabilities [Line Items]
Regulatory assets	$ 1,046,090	$ 861,065
Regulatory Liabilities	271,387	267,074
Deferred Regulatory Gain From Sale Leaseback [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory Liabilities	97,541	103,036
Removal Costs [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory Liabilities	82,338	70,342
Retail Energy Cost Adjustment [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory Liabilities	25,225	16,402
La Cygne Dismantling Costs [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory Liabilities	15,680	13,268
Nuclear Decommissioning Costs [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory Liabilities	12,544	25,467
Other Post-retirement Benefit Costs [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory Liabilities	11,125	6,943
Kansas Tax Credits [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory Liabilities	8,497	3,565
Fuel Supply and Energy Contracts [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory Liabilities	6,177	7,800
Ad Valorem Tax [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory Liabilities	0	4,934
Treasury Yield Hedges [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory Liabilities	0	7,711
Other Regulatory Liabilities [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory Liabilities	12,260	7,606
Deferred Employee Benefit Costs [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory assets	560,915	431,016
Deferred Income Tax Charges [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory assets	168,804	172,181
Depreciation [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory assets	76,298	79,770
Debt Reacquisition Costs [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory assets	66,856	73,099
Treasury Yield Hedges [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory assets	33,753	0
Storm Costs [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory assets	25,747	34,741
Wolf Creek Outage [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory assets	25,033	9,637
Asset Retirement Obligation [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory assets	22,196	21,546
Deferred Fuel Costs [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory assets	19,587	0
Energy Efficiency Program Costs [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory assets	16,521	10,980
Disallowed Plant Costs [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory assets	16,236	16,354
Ad Valorem Tax [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory assets	6,622	5,680
Other Regulatory Assets [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory assets	$ 7,522	$ 6,061

Rate Matters And Regulation (Narrative) (Details) (USD $)	0 Months Ended					9 Months Ended	12 Months Ended											12 Months Ended				12 Months Ended				12 Months Ended				12 Months Ended				12 Months Ended
	Oct. 15, 2011	Aug. 19, 2011	Feb. 23, 2011	Oct. 15, 2010	Oct. 15, 2009	Sep. 30, 2011	Dec. 31, 2011	Dec. 30, 2011	Oct. 27, 2011	May 27, 2011	Dec. 31, 2010	Oct. 29, 2010	Jun. 11, 2010	May 25, 2010	May 29, 2009	Mar. 06, 2009	Feb. 06, 2012 New Stipulation Agreement For Increase in Annual Retail Prices [Member]	Dec. 31, 2011 La Cygne Generating Station [Member]	Aug. 25, 2011 2011 General Rate Review [Member]	Jan. 21, 2009 2008 General Rate Review [Member]	Jan. 27, 2010 2009 Abbreviated Rate Review [Member]	Dec. 31, 2011 Retail Energy Cost Adjustment [Member] Y	Dec. 31, 2011 Ad Valorem Tax [Member] Y	Dec. 31, 2011 Other Pension Plans, Postretirement or Supplemental Plans, Defined Benefit [Member]	Dec. 31, 2011 Pension Cost [Member]	Dec. 31, 2011 Deferred Employee Benefit Costs [Member]	Dec. 31, 2010 Deferred Employee Benefit Costs [Member]	Dec. 31, 2011 Storm Costs [Member]	Dec. 31, 2010 Storm Costs [Member]	Dec. 31, 2011 Storm Costs [Member] Minimum [Member] Y	Dec. 31, 2011 Storm Costs [Member] Maximum [Member] Y	Dec. 31, 2011 Nuclear Refueling Outage Deferred Costs [Member] M	Dec. 31, 2010 Nuclear Refueling Outage Deferred Costs [Member]	Dec. 31, 2011 Retail Energy Cost Adjustment [Member] Y	Dec. 31, 2011 Energy Efficiency Program Costs [Member] Y	Dec. 31, 2011 Ad Valorem Tax [Member] Y	Dec. 31, 2010 Ad Valorem Tax [Member]
Regulatory Assets and Liabilities [Line Items]
Regulatory assets							$ 1,046,090,000				$ 861,065,000													$ 512,500,000	$ 48,400,000	$ 560,915,000	$ 431,016,000	$ 25,747,000	$ 34,741,000			$ 25,033,000	$ 9,637,000			$ 6,622,000	$ 5,680,000
Future Amortization Expense, Year One																										47,000,000
Proposed Increase In Annual Retail Revenues																			90,800,000
Regulatory Assets, Outage Period																																18
Regulatory Asset, Amortization Period																														3	5			1	1	1
Ownership Percentage																		50.00%
Environmental upgrades determined by using ratemaking principles		1,200,000,000	1,200,000,000				1,200,000,000
Proposed Increase In Retail Prices																	50,000,000
Expected increase In annual retail revenues																				130,000,000	17,100,000
Expected increase to annual transmission revenues	38,200,000			15,900,000	16,800,000
Environmental costs						600,000,000	600,000,000
Estimated Increase In Annual Retail Revenues For Environmental Costs										10,400,000				13,800,000	32,500,000
Estimated Increase In Annual Retail Revenues For Transmission Costs								17,400,000					6,400,000			31,800,000
Estimated Increase In Annual Retail Revenues For Energy Efficiency									$ 4,900,000			$ 5,800,000
Regulatory Liability, Amortization Period																						1	1

Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management (Narrative) (Details) (USD $)	12 Months Ended						0 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Jul. 21, 2010	Dec. 31, 2011 Cash Flow Hedging [Member]	Dec. 31, 2011 Other Current Liabilities [Member]	Dec. 31, 2010 Other Assets [Member]	Jan. 20, 2012 Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Obligation to return cash collateral	$ 2,900,000	$ 700,000
Notional amount			125,000,000
Right to reclaim cash collateral	0	0
Interest Rate Cash Flow Hedge Liability at Fair Value					34,000,000
Aggregate fair value of derivative instruments with credit-risk-related contingent features	3,100,000	1,600,000
Aggregate fair value of collateral already posted	0	0
Treasury yield hedges						7,700,000
Aggregate fair value additional collateral	500,000	1,600,000
Long-term regulatory assets	922,272,000	787,585,000		33,800,000
Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net	200,000
Settlement cost							$ 27,500,000

Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management (Carrying Values And Fair Values Of Financial Instruments) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 0	$ 61
Equipment financing loan that matured	9,913	0
Carrying Value	2,495,003	2,495,374
Fixed Rate Debt Member
Debt Instrument [Line Items]
Carrying Value	2,373,063	2,373,373
Fair Value	2,623,993	2,570,648
Fixed Rate Debt Of Variable Interest Entities [Member]
Debt Instrument [Line Items]
Carrying Value	275,738	308,317
Fair Value	$ 306,027	$ 341,328

Including current and noncurrent portions, aggregate carrying amount of long-term borrowings as of the balance sheet date before deducting unamortized discount or premiums (if any). May include notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt, which had initial maturities beyond one year or beyond the normal operating cycle, if longer.

+ References+ Details

Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management (Fair Value Of Assets And Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Energy Marketing Contracts, Assets	$ 15,731	$ 22,477
Total Nuclear Decommissioning Trust	130,270	126,990
Total Trading Securities, Assets	40,201	39,412
Total Assets Measured at Fair Value	186,202	196,590
Energy Marketing Contracts, Liabilities		9,680
Total Liabilities Measured at Fair Value	40,378
Level 1 [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	51	44
Total Trading Securities, Assets	169	0
Total Assets Measured at Fair Value	220	2,476
Total Liabilities Measured at Fair Value	0
Level 2 [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	119,193	120,725
Total Trading Securities, Assets	40,032	39,412
Total Assets Measured at Fair Value	161,626	174,106
Total Liabilities Measured at Fair Value	36,500
Level 3 [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	11,026	6,221
Total Trading Securities, Assets	0	0
Total Assets Measured at Fair Value	24,356	20,008
Total Liabilities Measured at Fair Value	3,878
Energy Marketing Contracts [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Energy Marketing Contracts, Assets	15,731	22,477
Energy Marketing Contracts, Liabilities	6,353	9,680
Energy Marketing Contracts [Member] \| Level 1 [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Energy Marketing Contracts, Assets	0	2,432
Energy Marketing Contracts, Liabilities	0	1,888
Energy Marketing Contracts [Member] \| Level 2 [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Energy Marketing Contracts, Assets	2,401	6,258
Energy Marketing Contracts, Liabilities	2,475	5,820
Energy Marketing Contracts [Member] \| Level 3 [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Energy Marketing Contracts, Assets	13,330	13,787
Energy Marketing Contracts, Liabilities	3,878	1,972
Treasury Yield Hedges [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Treasury yield hedges		7,711
Treasury Yield Hedges	34,025
Treasury Yield Hedges [Member] \| Level 1 [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Treasury yield hedges		0
Treasury Yield Hedges	0
Treasury Yield Hedges [Member] \| Level 2 [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Treasury yield hedges		7,711
Treasury Yield Hedges	34,025
Treasury Yield Hedges [Member] \| Level 3 [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Treasury yield hedges		0
Treasury Yield Hedges	0
Domestic Equity [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	57,117	63,453
Total Trading Securities, Assets	21,175	21,207
Domestic Equity [Member] \| Level 1 [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	0	0
Total Trading Securities, Assets	0	0
Domestic Equity [Member] \| Level 2 [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	53,186	60,586
Total Trading Securities, Assets	21,175	21,207
Domestic Equity [Member] \| Level 3 [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	3,931	2,867
Total Trading Securities, Assets	0	0
International Equity [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	22,307	18,966
Total Trading Securities, Assets	4,896	5,128
International Equity [Member] \| Level 1 [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	0	0
Total Trading Securities, Assets	0	0
International Equity [Member] \| Level 2 [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	22,307	18,966
Total Trading Securities, Assets	4,896	5,128
International Equity [Member] \| Level 3 [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	0	0
Total Trading Securities, Assets	0	0
Core Bonds [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	20,171	31,906
Total Trading Securities, Assets	13,961	13,077
Core Bonds [Member] \| Level 1 [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	0	0
Total Trading Securities, Assets	0	0
Core Bonds [Member] \| Level 2 [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	20,171	31,906
Total Trading Securities, Assets	13,961	13,077
Core Bonds [Member] \| Level 3 [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	0	0
Total Trading Securities, Assets	0	0
High-Yield Bonds [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	10,969	9,572
High-Yield Bonds [Member] \| Level 1 [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	0	0
High-Yield Bonds [Member] \| Level 2 [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	10,969	9,267
High-Yield Bonds [Member] \| Level 3 [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	0	305
Emerging Market Bonds [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	5,309
Emerging Market Bonds [Member] \| Level 1 [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	0
Emerging Market Bonds [Member] \| Level 2 [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	5,309
Emerging Market Bonds [Member] \| Level 3 [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	0
Combination Debt and Equity Fund [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	7,251
Combination Debt and Equity Fund [Member] \| Level 1 [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	0
Combination Debt and Equity Fund [Member] \| Level 2 [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	7,251
Combination Debt and Equity Fund [Member] \| Level 3 [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	0
Real Estate Securities [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	7,095	3,049
Real Estate Securities [Member] \| Level 1 [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	0	0
Real Estate Securities [Member] \| Level 2 [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	0	0
Real Estate Securities [Member] \| Level 3 [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	7,095	3,049
Cash Equivalents [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	51	44
Total Trading Securities, Assets	169
Cash Equivalents [Member] \| Level 1 [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	51	44
Total Trading Securities, Assets	169
Cash Equivalents [Member] \| Level 2 [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	0	0
Total Trading Securities, Assets	0
Cash Equivalents [Member] \| Level 3 [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	0	0
Total Trading Securities, Assets	$ 0

Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents Trading Securities which consist of all investments in certain debt and equity securities that are bought and held principally for the purpose of selling them in the near term (thus held for only a short period of time) or for which an entity has elected the fair value option. Trading generally reflects active and frequent buying and selling, and trading securities are generally used with the objective of generating profits on short-term differences in price, but this category of investments may also include items which are not intended to be sold in the near term or for which the fair value option has been elected.

+ References+ Details

Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management (Reconciliations Of Assets And Liabilities At Fair Value) (Details) (USD $)
In Thousands, unless otherwise specified

12 Months Ended

Dec. 31, 2011

Dec. 31, 2010

$ 18,036

$ 15,948

603

^[1]

(2,585)

^[1]

(1,450)

3,311

4,142

7,945

(2,082)

615

614

(6,583)

Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]

20,478

18,036

Energy Marketing Contracts, Net [Member]

11,815

4,310

603

^[1]

(2,585)

^[1]

(1,450)

^[2]

3,311

^[2]

2,993

^[2]

8,148

^[2]

(6,145)

1,022

614

(1,369)

Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]

9,452

11,815

Domestic Equity [Member]

2,867

2,262

^[2]

^[1]

479

608

(23)

589

Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]

3,931

2,867

High-Yield Bonds [Member]

305

5,741

^[1]

367

(305)

(5,803)

Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]

305

Real Estate Securities [Member]

3,049

3,635

^[1]

670

(586)

3,455

(79)

Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]

$ 7,095

$ 3,049

[1]	Unrealized gains and losses included in earnings are reported in revenues.
[2]	Includes changes in the fair value of certain fuel supply and electricity contracts.

Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management (Unrealized Gains And Losses On Financial Statements) (Details) (USD $)
In Thousands, unless otherwise specified

12 Months Ended

Dec. 31, 2011

Dec. 31, 2010

$ (898)

^[1]

$ (1,441)

^[1]

(747)

180

2,783

2,039

Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]

1,138

778

Energy Marketing Contracts, Net [Member]

(898)

^[1]

(1,441)

^[1]

(747)

^[2]

180

^[2]

1,736

^[2]

2,633

^[2]

Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]

1,372

Domestic Equity [Member]

^[1]

456

Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]

456

High-Yield Bonds [Member]

^[1]

(31)

Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]

(31)

Real Estate Securities [Member]

^[1]

591

(586)

$ 591

$ (586)

[1]	Unrealized gains and losses included in earnings are reported in revenues.
[2]	Includes changes in the fair value of certain fuel supply and electricity contracts.

Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management (Investments In Financial Instruments) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	$ 130,270	$ 126,990
Total Trading Securities, Assets	40,201	39,412
Total	186,202	196,590
Domestic Equity [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	57,117	63,453
Total Trading Securities, Assets	21,175	21,207
High-Yield Bonds [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	10,969	9,572
International Equity [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	22,307	18,966
Total Trading Securities, Assets	4,896	5,128
Core Bonds [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	20,171	31,906
Total Trading Securities, Assets	13,961	13,077
Real Estate Securities [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	7,095	3,049
Cash Equivalents [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	51	44
Total Trading Securities, Assets	169
Fair Value [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	11,026	6,221
Total Trading Securities, Assets	40,032	39,412
Total	51,058	45,633
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments	1,914	2,523
Fair Value [Member] \| Domestic Equity [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	3,931	2,867
Total Trading Securities, Assets	21,175	21,207
Fair Value [Member] \| High-Yield Bonds [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	0	305
Fair Value [Member] \| International Equity [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Trading Securities, Assets	4,896	5,128
Fair Value [Member] \| Core Bonds [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Trading Securities, Assets	13,961	13,077
Fair Value [Member] \| Real Estate Securities [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Total Nuclear Decommissioning Trust	7,095	3,049
Decommissioning Trust Assets [Member] \| Fair Value [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments	1,914	2,523
Decommissioning Trust Assets [Member] \| Fair Value [Member] \| Domestic Equity [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments	1,914	2,523
Decommissioning Trust Assets [Member] \| Fair Value [Member] \| High-Yield Bonds [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments	0	0
Decommissioning Trust Assets [Member] \| Fair Value [Member] \| Real Estate Securities [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments	0	0
Trading Securities [Member] \| Fair Value [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments	0	0
Trading Securities [Member] \| Fair Value [Member] \| Domestic Equity [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments	0	0
Trading Securities [Member] \| Fair Value [Member] \| International Equity [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments	0	0
Trading Securities [Member] \| Fair Value [Member] \| Core Bonds [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments	$ 0	$ 0

+ References+ Details

Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management (Fair Value Of Commodity Derivative Instruments) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Derivative instruments not designated as hedging instruments, energy marketing contracts, assets	$ 15,731	$ 22,477
Derivative instruments not designated as hedging instruments, energy marketing contracts, liabilities		9,680
Energy Marketing Contracts [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Derivative instruments not designated as hedging instruments, energy marketing contracts, assets	15,731	22,477
Derivative instruments not designated as hedging instruments, energy marketing contracts, liabilities	6,353	9,680
Current Assets [Member] \| Energy Marketing Contracts [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Derivative instruments not designated as hedging instruments, energy marketing contracts, assets	8,180	13,005
Other Assets [Member] \| Energy Marketing Contracts [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Derivative instruments not designated as hedging instruments, energy marketing contracts, assets	7,551	9,472
Current Liabilities [Member] \| Energy Marketing Contracts [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Derivative instruments not designated as hedging instruments, energy marketing contracts, liabilities	6,353	9,670
Long-Term Liabilities [Member] \| Energy Marketing Contracts [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Derivative instruments not designated as hedging instruments, energy marketing contracts, liabilities		$ 10

Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management (Changes In The Fair Value Of Commodity Derivative Instruments) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Revenues Increase [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Revenues increase (decrease), Net Gain Recognized	$ 1,569	$ 712
Revenues Decrease [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Revenues increase (decrease), Net Loss Recognized	0
Regulatory Assets Increase [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Regulatory assets decrease, Net Loss Recognized	374
Regulatory Liabilities Increase [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Regulatory liabilities (decrease) increase, Net Gain Recognized	0	1,799
Regulatory Assets Decrease [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Regulatory assets decrease, Net Gain Recognized	0	(7,604)
Regulatory Liabilities Decrease [Member]
Financial And Derivative Instruments, Trading Securities, Energy Marketing And Risk Management [Line Items]
Regulatory liabilities (decrease) increase, Net Loss Recognized	$ (1,623)

Financial Investments (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Schedule of Available-for-sale Securities [Line Items]
Unrealized gains (losses)	$ 0.3	$ 4.3	$ 11.3
Fair value of the debt securities in the NDT fund	36.4
Realized gains (losses) on available-for-sale-securities	$ 1.3	$ 13.2	$ (7.8)
Core Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Core bond fund investment limit percent, minimum	80.00%

For an unclassified balance sheet, total of debt securities categorized neither as held-to-maturity nor trading.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 13

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 12

-Subparagraph b

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 22

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 16

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 137

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6379932&loc=d3e22054-111558

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26610-111562

Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 320

-Section 50

-Paragraph 2

-Subparagraph (b)-(g)

-URI http://asc.fasb.org/extlink&oid=6957658&loc=d3e62557-112803

Reference 9: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS115-1/124-1

-Paragraph 15C

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 10: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS115-1/124-1

-Paragraph 15D

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

The net change in the difference between the fair value and the carrying value, or in the comparative fair values, of trading securities held at each balance sheet date, that was included in earnings for the period. Trading securities are bought and held principally for the purpose of selling them in the near term (thus held for only a short period of time) and the change in net unrealized holding gain (loss) is included in earnings for the period.

+ Details

Financial Investments (Costs And Fair Values Of Investments) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Schedule of Available-for-sale Securities [Line Items]
Cost	$ 133,213	$ 123,232
Gross Unrealized Gain	2,168	7,175
Gross Unrealized Loss	(5,111)	(3,417)
Fair Value	130,270	126,990
Available-for-sale Securities, Security Type Allocation Percentage	100.00%	100.00%
Domestic Equity [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost	55,357	58,592
Gross Unrealized Gain	1,760	4,972
Gross Unrealized Loss	0	(111)
Fair Value	57,117	63,453
Available-for-sale Securities, Security Type Allocation Percentage	44.00%	50.00%
International Equity [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost	24,501	17,249
Gross Unrealized Gain	0	1,717
Gross Unrealized Loss	(2,194)	0
Fair Value	22,307	18,966
Available-for-sale Securities, Security Type Allocation Percentage	17.00%	15.00%
Core Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost	19,771	32,054
Gross Unrealized Gain	400	0
Gross Unrealized Loss	0	(148)
Fair Value	20,171	31,906
Available-for-sale Securities, Security Type Allocation Percentage	16.00%	25.00%
High-Yield Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost	11,046	9,086
Gross Unrealized Gain	0	486
Gross Unrealized Loss	(77)	0
Fair Value	10,969	9,572
Available-for-sale Securities, Security Type Allocation Percentage	8.00%	8.00%
Emerging Market Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost	5,301
Gross Unrealized Gain	8
Gross Unrealized Loss	0
Fair Value	5,309
Available-for-sale Securities, Security Type Allocation Percentage	4.00%
Combination Debt and Equity Fund [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost	7,524
Gross Unrealized Gain	0
Gross Unrealized Loss	(273)
Fair Value	7,251
Available-for-sale Securities, Security Type Allocation Percentage	6.00%
Real Estate Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost	9,662	6,207
Gross Unrealized Gain	0	0
Gross Unrealized Loss	(2,567)	(3,158)
Fair Value	7,095	3,049
Available-for-sale Securities, Security Type Allocation Percentage	5.00%	2.00%
Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Cost	51	44
Gross Unrealized Gain	0	0
Gross Unrealized Loss	0	0
Fair Value	$ 51	$ 44
Cash Equivalents [Member] \| Maximum [Member]
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Security Type Allocation Percentage	1.00%	1.00%

This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References+ Details

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents Available-for-sale Securities which consist of all investments in certain debt and equity securities neither classified as trading or held-to-maturity securities. A debt security represents a creditor relationship with an enterprise. Debt securities include, among other items, US Treasury securities, US government securities, municipal securities, corporate bonds, convertible debt, commercial paper, and all securitized debt instruments. An equity security represents an ownership interest in an enterprise or the right to acquire or dispose of an ownership interest in an enterprise at fixed or determinable prices. Equity securities include, among other things, common stock, certain preferred stock, warrant rights, call options, and put options, but do not include convertible debt. An entity may opt to provide the reader with additional narrative text to better understand the nature of investments in debt and equity securities which are categorized as Available-for-sale.

+ References+ Details

This item represents the gross unrealized gains for securities, at a point in time, which are categorized neither as held-to-maturity nor trading securities.

+ References+ Details

Financial Investments (Fair Value And The Gross Unrealized Losses Of the Available-For-Sale Securities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less than 12 Months	$ 40,527	$ 34,773
Gross Unrealized Losses, Less than 12 Months	(2,544)	(259)
Fair Value, 12 Months or Greater	7,095	3,049
Gross Unrealized Losses, 12 Months or Greater	(2,567)	(3,158)
Fair Value, Total	47,622	37,822
Gross Unrealized Losses, Total	(5,111)	(3,417)
International Equity [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less than 12 Months	22,307
Gross Unrealized Losses, Less than 12 Months	(2,194)
Fair Value, 12 Months or Greater	0
Gross Unrealized Losses, 12 Months or Greater	0
Fair Value, Total	22,307
Gross Unrealized Losses, Total	(2,194)
High-Yield Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less than 12 Months	10,969
Gross Unrealized Losses, Less than 12 Months	(77)
Fair Value, 12 Months or Greater	0
Gross Unrealized Losses, 12 Months or Greater	0
Fair Value, Total	10,969
Gross Unrealized Losses, Total	(77)
Combination Debt/Equity Fund [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less than 12 Months	7,251
Gross Unrealized Losses, Less than 12 Months	(273)
Fair Value, 12 Months or Greater	0
Gross Unrealized Losses, 12 Months or Greater	0
Fair Value, Total	7,251
Gross Unrealized Losses, Total	(273)
Domestic Equity [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less than 12 Months		2,867
Gross Unrealized Losses, Less than 12 Months		(111)
Fair Value, 12 Months or Greater		0
Gross Unrealized Losses, 12 Months or Greater		0
Fair Value, Total		2,867
Gross Unrealized Losses, Total		(111)
Core Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less than 12 Months		31,906
Gross Unrealized Losses, Less than 12 Months		(148)
Fair Value, 12 Months or Greater		0
Gross Unrealized Losses, 12 Months or Greater		0
Fair Value, Total		31,906
Gross Unrealized Losses, Total		(148)
Real Estate Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Fair Value, Less than 12 Months	0	0
Gross Unrealized Losses, Less than 12 Months	0	0
Fair Value, 12 Months or Greater	7,095	3,049
Gross Unrealized Losses, 12 Months or Greater	(2,567)	(3,158)
Fair Value, Total	7,095	3,049
Gross Unrealized Losses, Total	$ (2,567)	$ (3,158)

This item represents the excess of amortized cost basis over fair value of securities in a loss position and which are categorized neither as held-to-maturity nor trading securities.

+ References+ Details

This item represents the aggregate fair value of investments in debt and equity securities in an unrealized loss position which are categorized neither as held-to-maturity nor trading securities.

+ References+ Details

This item represents the excess of amortized cost basis over fair value of securities that have been in a loss position for less than twelve months for those securities which are categorized neither as held-to-maturity nor trading securities.

+ References+ Details

This item represents the aggregate fair value of investments in debt and equity securities categorized neither as held-to-maturity nor trading securities that have been in a continuous unrealized loss position for less than twelve months.

+ References+ Details

+ References+ Details

Property, Plant And Equipment (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Public Utility, Property, Plant and Equipment [Line Items]
Construction work in progress	$ 534,003	$ 392,701
Nuclear fuel, net	75,695	78,102
Property, plant and equipment, net	6,411,922	5,964,439
Electricity Plant [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Electric plant in service	8,703,278	8,254,884
Electric plant acquisition adjustment	802,318	802,318
Accumulated depreciation	(3,703,372)	(3,563,566)
Electric plant, net	5,802,224	5,493,636
Variable Interest Entity [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	333,494	345,037
Variable Interest Entity [Member] \| Electricity Generation Plant, Non-Nuclear [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Electric plant in service	543,548	543,593
Accumulated depreciation	$ (210,054)	$ (198,556)

Tangible assets that are held by an entity for use in the production or supply of goods and services, for rental to others, or for administrative purposes and that are expected to provide economic benefit for more than one year; net of accumulated depreciation. Examples include land, buildings, machinery and equipment, and other types of furniture and equipment including, but not limited to, office equipment, furniture and fixtures, and computer equipment and software.

+ References+ Details

Property, Plant And Equipment (Depreciation) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Public Utility, Property, Plant and Equipment [Line Items]
Depreciation	$ 262.6	$ 249.2	$ 228.6
Variable Interest Entity [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Depreciation	$ 9.8	$ 9.7

Jointly Owned Utility Plant, Net Ownership Amount [Abstract]

The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

+ References+ Details

Joint Ownership of Utility Plants Joint Ownership of Utility Plants (Details) (USD $)
In Thousands, unless otherwise specified

12 Months Ended

Dec. 31, 2011

Dec. 31, 2010

Dec. 31, 2011

La Cygne unit 1 [Member]

Dec. 31, 2011

JEC unit 1 [Member]

Dec. 31, 2011

JEC unit 2 [Member]

Dec. 31, 2011

JEC unit 3 [Member]

Dec. 31, 2011

Wolf Creek [Member]

Dec. 31, 2011

State Line [Member]

Dec. 31, 2011

La Cygne Generating Station [Member]

Dec. 31, 2011

Jeffrey Energy Center [Member]

Dec. 31, 2011

La Cygne unit 2 [Member]

Dec. 31, 2011

Variable Interest Entity, Primary Beneficiary [Member]

Dec. 31, 2010

Variable Interest Entity, Primary Beneficiary [Member]

Dec. 31, 2011

Variable Interest Entity, Primary Beneficiary [Member]

La Cygne unit 2 [Member]

Investment

$ 3,633,835

$ 332,862

^[1]

$ 488,180

^[1]

$ 508,327

^[1]

$ 677,277

^[1]

$ 1,515,165

^[2]

$ 112,024

^[3]

Accumulated Depreciation

1,590,157

148,890

^[1]

207,206

^[1]

186,660

^[1]

268,909

^[1]

732,651

^[2]

45,841

^[3]

Construction Work in Progress

164,568

68,724

^[1]

49,755

^[1]

6,770

^[1]

37,740

^[2]

1,579

^[3]

Net MW

3,121

368

^[1]

666

^[1]

667

^[1]

672

^[1]

547

^[2]

201

^[3]

343

Jointly Owned Utility Plant, Proportionate Ownership Share

47.00%

50.00%

^[1]

92.00%

^[1]

92.00%

^[1]

92.00%

^[1]

47.00%

^[2]

40.00%

^[3]

Variable Interest Entity Percentage of Asset Held

50.00%

8.00%

Property, Plant and Equipment, Net

6,411,922

5,964,439

333,494

345,037

392,100

Public Utilities, Property, Plant and Equipment, Accumulated Depreciation

$ 173,100

[1]	Jointly owned with KCPL. Our 8% leasehold interest in JEC that is consolidated as a VIE is reflected in the net megawatts (MW) and ownership percentage provided above, but not in the other amounts in the table.
[2]	Jointly owned with KCPL and Kansas Electric Power Cooperative, Inc.
[3]	Jointly owned with Empire District Electric Company.

+ References+ Details

Short-Term Debt (Details) (USD $)	12 Months Ended							12 Months Ended	0 Months Ended			0 Months Ended
Short-Term Debt (Details) (USD $)	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Sep. 29, 2011	Feb. 18, 2011	Dec. 31, 2011 Commercial Paper and Revolving LIne of Credit [Member]	Dec. 31, 2010 Commercial Paper and Revolving LIne of Credit [Member]	Dec. 31, 2011 Commercial Paper [Member] days	Sep. 29, 2011 Revolving Credit Facility Lender One [Member] Y	Dec. 31, 2011 Revolving Credit Facility Lender One [Member]	Dec. 31, 2010 Revolving Credit Facility Lender One [Member]	Feb. 18, 2011 Bank Syndicates [Member] Y	Dec. 31, 2011 Bank Syndicates [Member]
Short-term Debt [Line Items]
Commercial paper program, Maximum amount outstanding						$ 1,000,000,000		$ 1,000,000,000
Commercial paper program, Maximim maturity period								365
Short-term debt amount outstanding	286,300,000	226,700,000						0
Secured revolving credit facility				730,000,000	270,000,000				730,000,000			270,000,000
Line of credit facility expiration date									September 29, 2016			February 18, 2015
Expected number of years for extending line of credit facility									2			2
Expected extended amount for line of credit									1,000,000,000			400,000,000
Secured revolving credit facility borrowed										286,300,000	226,700,000		0
Issued letters of credit										12,200,000	21,500,000
Weighted average interest rate						1.49%	0.61%
Interest expense on short-term debt	3,900,000	1,900,000	2,200,000
Weighted average amount outstanding	$ 362,946,000	$ 213,041,000
Weighted daily average interest rate, excluding fees	0.82%	0.63%

Long-Term Debt (Details) (USD $)
In Thousands, unless otherwise specified

Dec. 31, 2011

Dec. 31, 2010

Jun. 11, 2009

Unamortized debt discount, Net

$ 2,495,003

$ 2,495,374

(3,894)

^[1]

(4,442)

^[1]

Long-term debt due within one year

(61)

2,491,109

2,490,871

Westar Energy [Member] | Secured Debt [Member]

1,350,000

132,745

133,030

Westar Energy [Member] | Secured Debt [Member] | 6.00% First Mortgage Bonds Due 2014 [Member]

250,000

Westar Energy [Member] | Secured Debt [Member] | 5.15% First Mortgage Bonds Due 2017 [Member]

125,000

Westar Energy [Member] | Secured Debt [Member] | 5.95% First Mortgage Bonds Due 2035 [Member]

125,000

Westar Energy [Member] | Secured Debt [Member] | 5.10% First Mortgage Bonds Due 2020 [Member]

250,000

Westar Energy [Member] | Secured Debt [Member] | 5.875% First Mortgage Bonds Due 2036 [Member]

150,000

Westar Energy [Member] | Secured Debt [Member] | 6.10% First Mortgage Bonds Due 2047 [Member]

150,000

Westar Energy [Member] | Secured Debt [Member] | 8.625% First Mortgage Bonds Due 2018 [Member]

300,000

Westar Energy [Member] | Secured Debt [Member] | Pollution Control Bonds Variable Due 2032, 0.22% as of December 31, 2011; 0.60% as of December 31, 2010 [Member]

45,000

Westar Energy [Member] | Secured Debt [Member] | Pollution Control Bonds Variable Due 2032, 0.24% as of December 31, 2011; 0.54% as of December 31, 2010 [Member]

30,500

Westar Energy [Member] | Secured Debt [Member] | 5.00% Pollution Control Bonds Due 2033 [Member]

57,245

57,530

Westar Energy [Member] | Loans Payable [Member] | 4.36% Equipment Financing Loan Due 2011 [Member]

KGE [Member] | Secured Debt [Member]

625,000

387,258

387,283

KGE [Member] | Secured Debt [Member] | 6.53% First Mortgage Bonds Due 2037 [Member]

175,000

KGE [Member] | Secured Debt [Member] | 6.15% First Mortgage Bonds Due 2023 [Member]

50,000

KGE [Member] | Secured Debt [Member] | 6.64% First Mortgage Bonds Due 2038 [Member]

100,000

KGE [Member] | Secured Debt [Member] | 6.70% First Mortgage Bonds Due 2019 [Member]

300,000

KGE [Member] | Secured Debt [Member] | 5.10% Pollution Control Bonds Due 2023 [Member]

13,318

13,343

KGE [Member] | Secured Debt [Member] | Pollution Control Bonds Variable Due 2027, 0.28% as of December 31, 2011; 0.54% as of December 31, 2010 [Member]

21,940

KGE [Member] | Secured Debt [Member] | 5.30% Pollution Control Bonds Due 2031 [Member]

108,600

KGE [Member] | Secured Debt [Member] | 5.30% Pollution Control Bonds Due 2031 [Member]

18,900

KGE [Member] | Secured Debt [Member] | Pollution Control Bonds Variable Due 2032, 0.28% as of December 31, 2011; 0.54% as of December 31, 2010 [Member]

14,500

KGE [Member] | Secured Debt [Member] | Pollution Control Bonds Variable Due 2032, 0.28% as of December 31, 2011; 0.54% as of December 31, 2010 [Member]

10,000

KGE [Member] | Secured Debt [Member] | 4.85% Pollution Control Bonds Due 2031 [Member]

50,000

KGE [Member] | Secured Debt [Member] | 5.60% Pollution Control Bonds Due 2031 [Member]

50,000

KGE [Member] | Secured Debt [Member] | 6.00% Pollution Control Bonds Due 2031 [Member]

50,000

KGE [Member] | Secured Debt [Member] | 5.00% Pollution Control Bonds Due 2031 [Member]

50,000

Variable Interest Entity [Member]

Unamortized debt discount, Net

275,738

305,896

1,659

^[1]

2,421

^[1]

Long-term debt due within one year

(28,114)

(30,155)

249,283

278,162

Variable Interest Entity [Member] | Variable Interest Entities 7.77% due 2013 [Member]

2,583

^[2]

5,095

^[2]

Variable Interest Entity [Member] | Variable Interest Entities 6.99% due 2014 [Member]

2,094

^[2]

3,237

^[2]

Variable Interest Entity [Member] | Variable Interest Entities 5.92 % due 2019 [Member]

22,748

^[2]

31,171

^[2]

Variable Interest Entity [Member] | Variable Interest Entities 5.647% due 2021 [Member]

$ 248,313

^[2]

$ 266,393

^[2]

[1]	We amortize debt discounts and premiums to interest expense over the term of the respective issues.
[2]	Portions of our payments related to this debt reduce the principal balances each year until maturity.

+ References+ Details

The amount of debt discount (net of debt premium) that was originally recognized at the issuance of the instrument that has yet to be amortized.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 21

-Paragraph 16

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 1A

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28541-108399

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28567-108399

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28555-108399

Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 55

-Paragraph 8

-URI http://asc.fasb.org/extlink&oid=6584090&loc=d3e28878-108400

Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 21

-Paragraph 20

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Represents the current and noncurrent portions of a debt security issued by a state, certain agencies or authorities, a local government, or development corporation to finance the construction of air- or water-pollution control facilities or sewage or solid waste disposal facilities pursuant to federal law. The bonds are backed by the credit of the beneficiary of the financing rather than the credit of the issuer.

+ References+ Details

Long-term Debt Maturities (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011
Debt Instrument [Line Items]
2012	$ 0
2013	0
2014	250,000
2015	0
2016	0
Thereafter	2,245,003
Variable Interest Entity, Primary Beneficiary [Member]
Debt Instrument [Line Items]
2012	28,114
2013	25,941
2014	27,479
2015	27,933
2016	28,309
Thereafter	$ 137,962

Long-term Debt (textuals) (Details) (USD $)	12 Months Ended									0 Months Ended				0 Months Ended
Long-term Debt (textuals) (Details) (USD $)	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2011 Variable Interest Entity [Member]	Dec. 31, 2010 Variable Interest Entity [Member]	Dec. 31, 2009 Variable Interest Entity [Member]	Dec. 31, 2011 KGE [Member] First Mortgage Bond Series [Member]	Dec. 31, 2011 KGE [Member] Secured Debt [Member]	Dec. 31, 2010 KGE [Member] Secured Debt [Member]	Jun. 11, 2009 KGE [Member] Secured Debt [Member] 6.70% First Mortgage Bonds Due 2019 [Member]	Dec. 31, 2011 KGE [Member] Secured Debt [Member] 6.70% First Mortgage Bonds Due 2019 [Member]	Dec. 31, 2010 KGE [Member] Secured Debt [Member] 6.70% First Mortgage Bonds Due 2019 [Member]	Dec. 31, 2011 Westar Energy [Member] First Mortgage Bond Series [Member]	Aug. 03, 2009 Westar Energy [Member] Unsecured senior notes [Member]	Dec. 31, 2011 Westar Energy [Member] Secured Debt [Member]	Dec. 31, 2010 Westar Energy [Member] Secured Debt [Member]
Debt Instrument [Line Items]
Maximum Borrowing Capicity							$ 3,500,000,000
Remaining Borrowing Capacity							436,200,000						1,000,000,000
Assumed Interest Rate For Remaning Borrowing Capacity							4.125%
Long-term Debt, Percentage Bearing Variable Interest, Amount	121,900,000
Repayments of Long-term Debt	371,000	1,695,000	196,821,000	30,159,000	28,610,000	0								145,100,000
Stated interest percentage										6.70%				7.125%
Bond discount yielding percentage										6.725%
Long-term debt	2,495,003,000	2,495,374,000		275,738,000	305,896,000			625,000,000	625,000,000	300,000,000	300,000,000	300,000,000			1,350,000,000	1,350,000,000
net proceeds	0	0	347,507,000							297,500,000
Interest expense on long-term debt	$ 142,600,000	$ 144,100,000	$ 139,600,000	$ 16,800,000	$ 18,700,000

Taxes (Components of Income Tax Expense) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Current income taxes:
Federal	$ (8,575)	$ (32,107)	$ 2,428
State	196	(3,030)	9,975
Deferred income taxes:
Federal	93,089	102,568	46,148
State	21,337	20,305	3,003
Investment tax credit amortization	(2,703)	(2,704)	(2,704)
Income tax expense from continuing operations	103,344	85,032	58,850
Current income taxes:
Federal	0	0	(25,528)
State	0	0	(10,418)
Deferred income taxes:
Federal	0	0	(20,549)
Income tax expense from discontinued operations	0	0	(56,495)
Total income tax expense	$ 103,344	$ 85,032	$ 2,355

Taxes (Deferred Tax Assets and Liabilities in Balance Sheet) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Income Tax Disclosure [Abstract]
Current deferred tax assets	$ 394	$ 30,248
Non-current deferred tax liabilities	1,110,463	1,102,625
Net deferred tax liabilities	$ 1,110,069	$ 1,072,377

For entities that net deferred tax assets and tax liabilities, represents the unclassified net amount of deferred tax assets and liabilities as of the balance sheet date, which result from applying the applicable enacted tax rate to net temporary differences and carryforwards pertaining to assets or liabilities. A temporary difference is a difference between the tax basis of an asset or liability and its carrying amount in the financial statements prepared in accordance with generally accepted accounting principles that will reverse in ensuing periods.

+ References+ Details

For entities that net deferred tax assets and tax liabilities, represents the net amount of deferred tax assets (after reduction for valuation allowance) and liabilities as of the balance sheet date, which result from applying the applicable enacted tax rate to net temporary differences and carryforwards pertaining to assets or liabilities that are classified as current in the financial statements, or that are expected to reverse in the next twelve months (or normal operating cycle, if longer). A temporary difference is a difference between the tax basis of an asset or liability and its carrying amount in the financial statements prepared in accordance with generally accepted accounting principles that will reverse in ensuing periods. In a classified statement of financial position, an enterprise separates deferred tax liabilities and assets into a current amount and a noncurrent amount. Deferred tax liabilities and assets are classified as current or noncurrent based on the classification of the related asset or liability for financial reporting. A deferred tax liability or asset that is not related to an asset or liability for financial reporting, including deferred tax assets related to carryforwards, are classified according to the expected reversal date of the temporary difference.

+ References+ Details

For entities that net deferred tax assets and tax liabilities, represents the net amount of deferred tax assets (after reduction for valuation allowance) and liabilities as of the balance sheet date, which result from applying the applicable enacted tax rate to net temporary differences and carryforwards pertaining to assets or liabilities that are classified as noncurrent in the financial statements, or that are expected to reverse after the next twelve months (or beyond the normal operating cycle, if longer). A temporary difference is a difference between the tax basis of an asset or liability and its carrying amount in the financial statements prepared in accordance with generally accepted accounting principles that will reverse in ensuing periods. In a classified statement of financial position, an enterprise separates deferred tax liabilities and assets into a current amount and a noncurrent amount. Deferred tax liabilities and assets are classified as current or noncurrent based on the classification of the related asset or liability for financial reporting. A deferred tax liability or asset that is not related to an asset or liability for financial reporting, including deferred tax assets related to carryforwards, are classified according to the expected reversal date of the temporary difference.

+ References+ Details

Taxes (Schedule of Deferred Tax Assets and Liabilities) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Deferred Tax Assets, Net [Abstract]
Deferred employee benefit costs	$ 202,687,000	$ 155,400,000
Business tax credit carryforward	159,163,000	134,629,000
Net operating loss carryforward	84,365,000	0
Deferred regulatory gain on sale-leaseback	42,962,000	45,381,000
Deferred state income taxes	42,209,000	14,215,000
Alternative minimum tax carryforward	36,471,000	34,270,000
Deferred compensation	28,286,000	40,401,000
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Accrued Liabilities	16,912,000	35,714,000
Disallowed costs	12,717,000	13,357,000
Capital loss carryforward	12,554,000	3,527,000
Other	13,031,000	33,577,000
Total gross deferred tax assets	651,357,000	510,471,000
Less: Valuation allowance	13,712,000	59,415,000
Deferred tax assets	637,645,000	451,056,000
Deferred tax liabilities:
Accelerated depreciation	1,088,727,000	920,229,000
Deferred employee benefit costs	202,687,000	161,035,000
Acquisition premium	187,934,000	195,947,000
Amounts due from customers for future income taxes, net	168,804,000	172,181,000
Deferred state income taxes	39,512,000	16,577,000
Debt reacquisition costs	21,683,000	23,864,000
Pension expense tracker	14,600,000	8,446,000
Storm costs	10,176,000	13,733,000
Other	13,591,000	11,421,000
Total deferred tax liabilities	1,747,714,000	1,523,433,000
Net deferred tax liabilities	1,110,069,000	1,072,377,000
Capital loss carryforwards	31,700,000
Decrease in valuation allowance	(45,700,000)
Minimum [Member]
Deferred tax liabilities:
Tax credit carryforward period (in years)	10
Maximum [Member]
Deferred tax liabilities:
Tax credit carryforward period (in years)	16
Deferred Tax Asset, Capital Loss [Member]
Deferred Tax Assets, Net [Abstract]
Less: Valuation allowance	12,500,000
Deferred Tax Asset, Loss on Other Investments [Member]
Deferred Tax Assets, Net [Abstract]
Less: Valuation allowance	1,200,000
Deferred Tax Asset, State Investment Tax Credits [Member]
Deferred Tax Assets, Net [Abstract]
Less: Valuation allowance		51,900,000
Internal Revenue Service (IRS) [Member]
Deferred Tax Assets, Net [Abstract]
Business tax credit carryforward	29,700,000
Deferred tax liabilities:
Operating Loss Carryforwards	206,600,000
State and Local Jurisdiction [Member]
Deferred Tax Assets, Net [Abstract]
Business tax credit carryforward	$ 129,500,000

Taxes (Effective Income Tax Reconciliation) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Nov. 30, 2009
Effective Income Tax Rate, Continuing Operations, Tax Rate Reconciliation [Abstract]
Statutory federal income tax rate from continuing operations	35.00%	35.00%	35.00%
Corporate-owned life insurance policies	(4.50%)	(6.10%)	(8.20%)
State income taxes	4.10%	3.80%	4.30%
Production tax credits	(2.90%)	(3.40%)	(3.00%)
Accelerated depreciation flow through and amortization	1.80%	2.60%	3.70%
Amortization of federal investment tax credits	(0.80%)	(0.90%)	(1.40%)
AFUDC equity	(0.60%)	(0.40%)	(0.90%)
Capital loss utilization	(0.50%)	(0.70%)	(0.40%)
Liability for unrecognized income tax benefits	0.00%	(0.20%)	0.20%
Other	(1.20%)	(0.70%)	0.10%
Effective income tax rate from continuing operations	30.40%	29.00%	29.40%
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Tax Settlement Payment To Former Subsidiary	$ 0	$ 0	$ 22,750,000
Refund from tax examination				34,900,000
Results of discontinued operations, net of tax	0	0	33,745,000
Protection One [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Tax Settlement Payment To Former Subsidiary			$ (22,800,000)

Taxes (Unrecognized Tax Benefits) (Details) (USD $)	12 Months Ended
Taxes (Unrecognized Tax Benefits) (Details) (USD $)	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized income tax benefits at January 1	$ 1,888,000	$ 8,357,000	$ 38,980,000
Additions based on tax positions related to the current year	967,000	608,000	2,254,000
Additions for tax positions of prior years	939,000	2,323,000	0
Reductions for tax positions of prior years	(563,000)	(1,241,000)	(25,722,000)
Settlements	(748,000)	(8,159,000)	(7,155,000)
Unrecognized income tax benefits at December 31	2,483,000	1,888,000	8,357,000
Tax loss and credit carryforwards	200,000	1,000,000	23,700,000
The amounts of unrecognized income tax benefits that, if recognized, would favorably impact our effective income tax rate	1,200,000	1,300,000	2,100,000
Reversal interest expense previously recorded for income tax uncertainties	200,000	1,000,000	2,400,000
Accrued interest related to unrecognized income tax benefits	200,000	400,000
Penalties accrued	0	0
Taxes other than income taxes	$ 1,500,000	$ 3,600,000

Employee Benefit Plans (Funded Status) (Details) (USD $)
In Thousands, unless otherwise specified

12 Months Ended

Dec. 31, 2011

Dec. 31, 2010

Dec. 31, 2009

Pension Benefits [Member]

$ 747,460

$ 662,495

16,076

13,926

12,882

40,045

39,391

38,162

(31,107)

(29,690)

94,161

60,662

Amendments

676

9,673

^[1]

Expected return on plan assets

876,308

747,460

662,495

(31,087)

(38,384)

(37,826)

Transition obligation, net

Prior service costs

1,213

2,729

2,668

Actuarial loss, net

23,659

17,183

14,263

Regulatory adjustment

(22,098)

(12,167)

(9,188)

Net periodic cost

27,808

22,678

20,961

432,233

404,243

27,819

33,359

50,000

22,400

Part D Reimbursements

28,975

27,769

^[1]

481,077

432,233

404,243

Amounts Recognized in the Balance Sheets Consist of:

(395,231)

(315,227)

(2,741)

(2,030)

(392,490)

(313,197)

Amounts Recognized in Regulatory Assets Consist of:

(395,231)

(315,227)

397,691

323,924

4,606

5,819

402,297

329,743

Post-Retirement Benefits [Member]

137,759

128,998

1,803

1,526

1,529

6,793

7,083

6,917

3,390

3,292

(10,114)

(11,090)

5,246

7,950

Amendments

4,451

750

^[1]

Expected return on plan assets

150,078

137,759

128,998

(5,002)

(5,197)

(4,756)

Transition obligation, net

3,911

3,912

Prior service costs

2,524

2,154

1,580

Actuarial loss, net

702

321

(38)

Regulatory adjustment

1,344

1,868

2,280

Net periodic cost

12,075

11,667

11,424

86,984

74,114

(174)

9,849

10,793

10,512

(3,244)

(3,147)

Part D Reimbursements

317

9,739

10,955

750

^[1]

91,858

86,984

74,114

Amounts Recognized in the Balance Sheets Consist of:

(58,220)

(50,775)

(115)

(91)

(58,105)

(50,684)

Amounts Recognized in Regulatory Assets Consist of:

(58,220)

(50,775)

18,178

8,458

18,991

17,065

4,236

8,148

$ 41,405

$ 33,671

[1]	Other includes the $9.7 million reclassification of a contractual obligation related to the legal settlement with a former executive officer and $0.8 million of proceeds received as a result of the Early Retiree Reinsurance Program.

Employee Benefit Plans (Plans With a Projected Benefit Obligation and Accumulated Benefit Obligation in Excess of Plan Assets) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plans with Benefit Obligations in Excess of Plan Assets, Aggregate Benefit Obligation	$ 876,308	$ 747,460
Defined Benefit Plan, Plans with Benefit Obligations in Excess of Plan Assets, Aggregate Fair Value of Plan Assets	481,077	432,233
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Aggregate Accumulated Benefit Obligation	750,263	635,541
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Aggregate Fair Value of Plan Assets	481,077	432,233
Discount rate	4.50%	5.35%
Compensation rate increase	4.00%	4.00%
Post-Retirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Aggregate Accumulated Benefit Obligation	150,078	137,759
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Aggregate Fair Value of Plan Assets	$ 91,858	$ 86,984
Discount rate	4.25%	5.00%
Compensation rate increase	0.00%	0.00%

If aggregate disclosures are presented, the aggregate pension accumulated benefit obligation for pension plans with accumulated benefit obligations in excess of plan assets as of the measurement date of each statement of financial position presented.

+ References+ Details

If aggregate disclosures are presented, the aggregate fair value of plan assets for pension plans with accumulated benefit obligations in excess of plan assets as of the measurement date of each statement of financial position presented.

+ References+ Details

Employee Benefit Plans (Net Periodic Costs And Other Changes Recognized in Regulatory Assets) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Pension Benefits [Member]
Components of Net Periodic Cost (Benefit):
Service cost	$ 16,076	$ 13,926	$ 12,882
Interest cost	40,045	39,391	38,162
Expected return on plan assets	(31,087)	(38,384)	(37,826)
Transition obligation, net	0	0	0
Prior service costs	1,213	2,729	2,668
Actuarial loss/(gain), net	23,659	17,183	14,263
Net periodic cost before regulatory adjustment	49,906	34,845	30,149
Regulatory adjustment	(22,098)	(12,167)	(9,188)
Net periodic cost	27,808	22,678	20,961
Other Changes in Plan Assets and Benefit Obligations Recognized in Regulatory Assets:
Current year actuarial (gain)/loss	97,429	65,690	(34,610)
Amortization of actuarial (loss)/gain	(23,659)	(17,183)	(14,263)
Current year prior service cost	0	676	48
Amortization of prior service costs	(1,213)	(2,729)	(2,668)
Current year offset of initial transition asset due to plan change	0	0	0
Amortization of transition obligation	0	0	0
Total recognized in regulatory assets	72,557	46,454	(51,493)
Total recognized in net periodic cost and regulatory assets	100,365	69,132	(30,532)
Discount rate	5.35%	5.95%	6.10%
Expected long-term return on plan assets	6.50%	8.25%	8.25%
Compensation rate increase	4.00%	4.00%	4.00%
Post-Retirement Benefits [Member]
Components of Net Periodic Cost (Benefit):
Service cost	1,803	1,526	1,529
Interest cost	6,793	7,083	6,917
Expected return on plan assets	(5,002)	(5,197)	(4,756)
Transition obligation, net	3,911	3,912	3,912
Prior service costs	2,524	2,154	1,580
Actuarial loss/(gain), net	702	321	(38)
Net periodic cost before regulatory adjustment	10,731	9,799	9,144
Regulatory adjustment	1,344	1,868	2,280
Net periodic cost	12,075	11,667	11,424
Other Changes in Plan Assets and Benefit Obligations Recognized in Regulatory Assets:
Current year actuarial (gain)/loss	10,421	3,298	(26,205)
Amortization of actuarial (loss)/gain	(702)	(321)	38
Current year prior service cost	4,451	0	6,672
Amortization of prior service costs	(2,524)	(2,154)	(1,580)
Current year offset of initial transition asset due to plan change	0	0	(76)
Amortization of transition obligation	(3,911)	(3,912)	(3,912)
Total recognized in regulatory assets	7,735	(3,089)	(25,063)
Total recognized in net periodic cost and regulatory assets	$ 19,810	$ 8,578	$ (13,639)
Discount rate	5.00%	5.65%	6.05%
Expected long-term return on plan assets	6.00%	7.75%	7.75%
Compensation rate increase	0.00%	0.00%	0.00%

Employee Benefit Plans (Textual) (Details) (USD $)	12 Months Ended					12 Months Ended						12 Months Ended
Employee Benefit Plans (Textual) (Details) (USD $)	Dec. 31, 2011 Y bonds	Dec. 31, 2010	Dec. 31, 2009	Nov. 17, 2011	Dec. 31, 2011 Level 2 [Member]	Dec. 31, 2011 Pension Plans, Defined Benefit [Member]	Dec. 31, 2011 Other Postretirement Benefit Plans, Defined Benefit [Member]	Dec. 31, 2011 KGE [Member]	Dec. 31, 2011 Long Term Incentive and Share Award [Member]	May 19, 2011 Long Term Incentive and Share Award [Member]	May 18, 2011 Long Term Incentive and Share Award [Member]	Dec. 31, 2010 Stock Options [Member]	Dec. 31, 2011 Long Term Incentive and Share Award Plan Executive Stock For Compensation Program [Member]	Dec. 31, 2010 Long Term Incentive and Share Award Plan Executive Stock For Compensation Program [Member]	Dec. 31, 2009 Long Term Incentive and Share Award Plan Executive Stock For Compensation Program [Member]	Dec. 31, 2011 RSU Awards With Performance Measures [Member]	Dec. 31, 2010 RSU Awards With Performance Measures [Member]	Dec. 31, 2011 RSU Awards With Only Service Requirements [Member]	Dec. 31, 2010 RSU Awards With Only Service Requirements [Member]	Dec. 31, 2009 RSU Awards With Only Service Requirements [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan, Cost Recognized	$ 7,000,000	$ 7,400,000	$ 6,500,000
Share-based Compensation Arrangement by Share-based Payment Award, Plan Modification, Incremental Compensation Cost	2,800,000
Percentage of RSU Award, Minimum	0.00%
Percentage of RSU Award, Maximum	200.00%
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized																3,300,000		4,200,000
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Minimum	24.50%	25.20%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Maximum	28.50%	30.10%
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Minimum	0.10%	0.30%
Defined Benefit Plan, Target Allocation Percentage of Assets, Debt Securities						44.00%	35.00%
Plan Asset Allocation Restrictions, Maximum Allocation To The Common Stock Of One Corporation						5.00%	5.00%
Defined Benefit Plan, Net Periodic Benefit Cost			1,900,000
Subsidiary Interest in Defined Benefit Plans								47.00%
Interest Rate Yield Curve Basis, Number of Contributing Bonds	500
Interest Rate Yield Curve Basis, Maturities On Contributing Bonds, Minimum	0
Interest Rate Yield Curve Basis, Maturities On Contributing Bonds, Maximum	30
Defined Benefit Plan Target Allocation Percentage Of Assets Of Any One Issuer	10.00%
Defined Benefit Plan Target Allocation Percentage Of Assets Of Any One Industry	25.00%
Defined Benefit Plan, Target Allocation Percentage of Assets, Equity Securities						42.00%	65.00%
Defined Benefit Plan, Target Allocation Percentage of Assets, Real Estate						14.00%
US Government Securities, at Carrying Value					14,100,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized										8,250,000	5,000,000
Share-based Compensation Arrangement by Share-based Payment Award, Shares Purchased for Award									4,500,000
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate, Maximum	1.30%	1.40%
Employee Service Share-based Compensation, Nonvested Awards, Total Compensation Cost Not yet Recognized, Period for Recognition																1.7		1.9
Share-based Compensation Award Fair Value, Vested During Period		0														3,600,000	0	4,800,000	2,700,000	8,800,000
Temporary Equity, Carrying Amount	$ 0	$ 3,465,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period												0
Common Stock Dividends, Shares													4,757	6,627	7,106
Common stock, issued	125,698,396	112,128,068		8,500,000									67,426	1,198	563

Employee Benefit Plans (Estimated Amounts From Regulatory Assets Into Net Periodic Cost in 2012) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Estimated Future Change in Regulatory Assets, Reclassification, Pension and Other Postretirement Benefit Plans, Net Gain (Loss) Recognized in Net Periodic Benefit Cost	$ 32,782
Estimated Future Change in Regulatory Assets, Amortization, Pension and Other Postretirement Benefit Plans, Net Prior Service Cost (Credit) Recognized in Net Periodic Benefit Cost	613
Estimated Future Change in Regulatory Assets, Reclassification, Pension and Other Postretirement Benefit Plans, Net Transition Asset (Obligation), Recognized in Net Periodic Benefit Cost	0
Estimated Future Change in Regulatory Assets, Pension and Other Postretirement Benefit Plans, Adjustment, before Tax	33,395
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Estimated Future Change in Regulatory Assets, Reclassification, Pension and Other Postretirement Benefit Plans, Net Gain (Loss) Recognized in Net Periodic Benefit Cost	1,509
Estimated Future Change in Regulatory Assets, Amortization, Pension and Other Postretirement Benefit Plans, Net Prior Service Cost (Credit) Recognized in Net Periodic Benefit Cost	2,524
Estimated Future Change in Regulatory Assets, Reclassification, Pension and Other Postretirement Benefit Plans, Net Transition Asset (Obligation), Recognized in Net Periodic Benefit Cost	3,911
Estimated Future Change in Regulatory Assets, Pension and Other Postretirement Benefit Plans, Adjustment, before Tax	$ 7,944

Employee Benefit Plans (Assumed Annual Health Care Cost Growth Rates) (Details)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Health Care Cost Trend Rate Assumed for Next Fiscal Year	8.00%	8.00%
Defined Benefit Plan, Ultimate Health Care Cost Trend Rate	5.00%	5.00%
Defined Benefit Plan, Year that Rate Reaches Ultimate Trend Rate	2018	2018

The assumed health care cost trend rate for the next year used to measure the expected cost of benefits covered by the plan (gross eligible charges). This is based upon the annual rate of change in the cost of health care benefits currently provided by the postretirement benefit plan, due to factors other than changes in the composition of the plan population by age and dependency status.

+ References+ Details

Employee Benefit Plans (One Percentage Change In Assumed Health Care Cost Growth Rates Effects) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Effect of One Percentage Point Increase on Service and Interest Cost Components	$ 69
Defined Benefit Plan, Effect of One Percentage Point Decrease on Service and Interest Cost Components	(65)
Defined Benefit Plan, Effect of One Percentage Point Increase on Accumulated Postretirement Benefit Obligation	1,465
Defined Benefit Plan, Effect of One Percentage Point Decrease on Accumulated Postretirement Benefit Obligation	$ (1,362)

Employee Benefit Plans (Fair Value of Plan Assets) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	$ 91,858	$ 86,984	$ 74,114
Other Postretirement Benefit Plans, Defined Benefit [Member] \| Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Other Postretirement Benefit Plans, Defined Benefit [Member] \| Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	91,858	86,984
Other Postretirement Benefit Plans, Defined Benefit [Member] \| Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Other Postretirement Benefit Plans, Defined Benefit [Member] \| Private Equity Funds, Domestic [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	47,411	45,766
Other Postretirement Benefit Plans, Defined Benefit [Member] \| Private Equity Funds, Domestic [Member] \| Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Other Postretirement Benefit Plans, Defined Benefit [Member] \| Private Equity Funds, Domestic [Member] \| Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	47,411	45,766
Other Postretirement Benefit Plans, Defined Benefit [Member] \| Private Equity Funds, Domestic [Member] \| Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Other Postretirement Benefit Plans, Defined Benefit [Member] \| Private Equity Funds, Foreign [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	11,500	11,280
Other Postretirement Benefit Plans, Defined Benefit [Member] \| Private Equity Funds, Foreign [Member] \| Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Other Postretirement Benefit Plans, Defined Benefit [Member] \| Private Equity Funds, Foreign [Member] \| Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	11,500	11,280
Other Postretirement Benefit Plans, Defined Benefit [Member] \| Private Equity Funds, Foreign [Member] \| Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Other Postretirement Benefit Plans, Defined Benefit [Member] \| Core Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	32,192	29,938
Other Postretirement Benefit Plans, Defined Benefit [Member] \| Core Bonds [Member] \| Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Other Postretirement Benefit Plans, Defined Benefit [Member] \| Core Bonds [Member] \| Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	32,192	29,938
Other Postretirement Benefit Plans, Defined Benefit [Member] \| Core Bonds [Member] \| Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Other Postretirement Benefit Plans, Defined Benefit [Member] \| Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	755
Other Postretirement Benefit Plans, Defined Benefit [Member] \| Cash Equivalents [Member] \| Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0
Other Postretirement Benefit Plans, Defined Benefit [Member] \| Cash Equivalents [Member] \| Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	755
Other Postretirement Benefit Plans, Defined Benefit [Member] \| Cash Equivalents [Member] \| Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	481,077	432,233	404,243
Pension Plans, Defined Benefit [Member] \| Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Pension Plans, Defined Benefit [Member] \| Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	406,138	377,283
Pension Plans, Defined Benefit [Member] \| Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	74,939	54,950
Pension Plans, Defined Benefit [Member] \| Private Equity Funds, Domestic [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	136,739	128,825
Pension Plans, Defined Benefit [Member] \| Private Equity Funds, Domestic [Member] \| Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Pension Plans, Defined Benefit [Member] \| Private Equity Funds, Domestic [Member] \| Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	121,364	117,250
Pension Plans, Defined Benefit [Member] \| Private Equity Funds, Domestic [Member] \| Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	15,375	11,575
Pension Plans, Defined Benefit [Member] \| Private Equity Funds, Foreign [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	53,943	44,834
Pension Plans, Defined Benefit [Member] \| Private Equity Funds, Foreign [Member] \| Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Pension Plans, Defined Benefit [Member] \| Private Equity Funds, Foreign [Member] \| Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	53,943	44,834
Pension Plans, Defined Benefit [Member] \| Private Equity Funds, Foreign [Member] \| Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Pension Plans, Defined Benefit [Member] \| Core Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	142,700	183,361
Pension Plans, Defined Benefit [Member] \| Core Bonds [Member] \| Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Pension Plans, Defined Benefit [Member] \| Core Bonds [Member] \| Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	142,700	183,361
Pension Plans, Defined Benefit [Member] \| Core Bonds [Member] \| Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Pension Plans, Defined Benefit [Member] \| High-Yield Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	38,380	30,019
Pension Plans, Defined Benefit [Member] \| High-Yield Bonds [Member] \| Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Pension Plans, Defined Benefit [Member] \| High-Yield Bonds [Member] \| Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	38,380	28,819
Pension Plans, Defined Benefit [Member] \| High-Yield Bonds [Member] \| Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	1,200
Pension Plans, Defined Benefit [Member] \| Combination Debt Equity Fund Member
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	47,151
Pension Plans, Defined Benefit [Member] \| Combination Debt Equity Fund Member \| Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0
Pension Plans, Defined Benefit [Member] \| Combination Debt Equity Fund Member \| Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	47,151
Pension Plans, Defined Benefit [Member] \| Combination Debt Equity Fund Member \| Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0
Pension Plans, Defined Benefit [Member] \| Real Estate Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	18,848	16,411
Pension Plans, Defined Benefit [Member] \| Real Estate Bonds [Member] \| Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Pension Plans, Defined Benefit [Member] \| Real Estate Bonds [Member] \| Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Pension Plans, Defined Benefit [Member] \| Real Estate Bonds [Member] \| Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	18,848	16,411
Pension Plans, Defined Benefit [Member] \| Alternative Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	40,716	25,764
Pension Plans, Defined Benefit [Member] \| Alternative Funds [Member] \| Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Pension Plans, Defined Benefit [Member] \| Alternative Funds [Member] \| Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Pension Plans, Defined Benefit [Member] \| Alternative Funds [Member] \| Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	40,716	25,764
Pension Plans, Defined Benefit [Member] \| Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	2,600	3,019
Pension Plans, Defined Benefit [Member] \| Cash Equivalents [Member] \| Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	0	0
Pension Plans, Defined Benefit [Member] \| Cash Equivalents [Member] \| Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	2,600	3,019
Pension Plans, Defined Benefit [Member] \| Cash Equivalents [Member] \| Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Fair Value of Plan Assets	$ 0	$ 0

Assets, usually stocks, bonds, and other investments, that have been segregated and restricted (usually in a trust) to provide benefits, at their fair value as of the measurement date. Plan assets include amounts contributed by the employer (and by employees for a contributory plan) and amounts earned from investing the contributions, less benefits paid. If a plan has liabilities other than for benefits, those non-benefit obligations may be considered as reductions of plan assets.

+ References+ Details

Employee Benefit Plans (Changes in Level 3 Plan Assets Measured at Fair Value on a Recurring Basis) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Defined Benefit Plan Disclosure [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	$ 20,478	$ 18,036	$ 15,948
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases, Sales, Issuances, Settlements		(6,583)
Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	74,939	54,950	46,347
Defined Benefit Plan, Actual Return on Plan Assets Still Held	4,514	(907)
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period	(49)	4,248
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases, Sales, Issuances, Settlements	15,524	5,262
Alternative Funds [Member] \| Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	40,716	25,764	0
Defined Benefit Plan, Actual Return on Plan Assets Still Held	(48)	864
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period	0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases, Sales, Issuances, Settlements	15,000	24,900
Domestic Equity Securities [Member] \| Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	15,375	11,575	9,310
Defined Benefit Plan, Actual Return on Plan Assets Still Held	1,910	75
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period	0	0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases, Sales, Issuances, Settlements	1,890	2,190
High-Yield Bonds [Member] \| Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	0	1,200	22,519
Defined Benefit Plan, Actual Return on Plan Assets Still Held	0	(3,963)
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period	0	4,325
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases, Sales, Issuances, Settlements	(1,200)	(21,681)
Real Estate [Member] \| Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	18,848	16,411	14,518
Defined Benefit Plan, Actual Return on Plan Assets Still Held	2,652	2,117
Defined Benefit Plan, Actual Return on Plan Assets Sold During Period	(49)	(77)
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases, Sales, Issuances, Settlements	$ (166)	$ (147)

Employee Benefit Plans (Expected Cash Flows Related To Pension and Post-Retirement Benefit Plans) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011
Plan Trust [Member] \| Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
2012	$ 57.4
2012	(29.3)
2013	(31.1)
2014	(33.1)
2015	(35.1)
2016	(37.8)
2017 - 2021	(231.9)
Plan Trust [Member] \| Post-Retirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
2012	10.8
2012	(7.9)
2013	(8.3)
2014	(8.7)
2015	(9.3)
2016	(9.6)
2017 - 2021	(51.3)
Company Assets [Member] \| Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
2012	2.7
2012	(2.7)
2013	(2.7)
2014	(2.8)
2015	(2.8)
2016	(2.8)
2017 - 2021	(13.2)
Company Assets [Member] \| Post-Retirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
2012	0.1
2012	(0.1)
2013	(0.1)
2014	(0.1)
2015	(0.1)
2016	(0.1)
2017 - 2021	$ (0.7)

Employee Benefit Plans (Compensation expense and income tax benefits related to stock-based compensation arrangements included in net income) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Defined Benefit Plan Disclosure [Line Items]
Allocated Share-based Compensation Expense	$ 8,367	$ 11,321	$ 5,080
Employee Service Share-based Compensation, Tax Benefit from Compensation Expense	$ 3,309	$ 4,481	$ 2,011

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References+ Details

Employee Benefit Plans (RSU activity for awards) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
RSU Awards With Performance Measures [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Nonvested balance, beginning of year	348,400	0	0
Granted	244,400	366,000	0
Vested	(119,500)	(4,500)	0
Forfeited	(149,100)	(13,100)	0
Nonvested balance, end of year	324,200	348,400	0
Weighted Average Grant Date Fair Value, beginning of year	$ 24.98	$ 0.00	$ 0.00
Grants in Period, Weighted Average Grant Date Fair Value	$ 31.26	$ 24.96	$ 0.00
Vested in Period, Weighted Average Grant Date Fair Value	$ 24.12	$ 23.32	$ 0.00
Forfeited in Period, Weighted Average Grant Date Fair Value	$ 28.72	$ 24.99	$ 0.00
Weighted Average Grant Date Fair Value, end of year	$ 28.31	$ 24.98	$ 0.00
RSU Awards With Only Service Requirements [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested [Roll Forward]
Nonvested balance, beginning of year	600,400	368,800	727,400
Granted	284,100	366,400	83,500
Vested	(187,300)	(118,100)	(439,000)
Forfeited	(328,700)	(16,700)	(3,100)
Nonvested balance, end of year	368,500	600,400	368,800
Weighted Average Grant Date Fair Value, beginning of year	$ 21.50	$ 21.98	$ 20.86
Grants in Period, Weighted Average Grant Date Fair Value	$ 26.30	$ 22.14	$ 18.33
Vested in Period, Weighted Average Grant Date Fair Value	$ 23.50	$ 24.81	$ 19.43
Forfeited in Period, Weighted Average Grant Date Fair Value	$ 24.37	$ 22.32	$ 20.63
Weighted Average Grant Date Fair Value, end of year	$ 23.83	$ 21.50	$ 21.98

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

+ References+ Details

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

+ References+ Details

The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

+ References+ Details

The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

+ References+ Details

Wolf Creek Employee Benefit Plans (Net Periodic Costs For Pension And Post-Retirement Benefit Plans) (Details) (USD $)
In Thousands, unless otherwise specified

12 Months Ended

Dec. 31, 2011

Dec. 31, 2010

Dec. 31, 2009

Wolf Creek [Member]

$ 80,727

$ 76,086

Pension Benefits [Member]

747,460

662,495

16,076

13,926

12,882

40,045

39,391

38,162

31,107

29,690

94,161

60,662

9,673

^[1]

876,308

747,460

662,495

432,233

404,243

27,819

33,359

50,000

22,400

28,975

27,769

481,077

432,233

404,243

Amounts Recognized in Regulatory Assets Consist of:

(395,231)

(315,227)

2,741

2,030

Pension and Other Postretirement Defined Benefit Plans, Liabilities

392,490

313,197

(395,231)

(315,227)

Amounts Recognized in Regulatory Assets Consist of:

397,691

323,924

4,606

5,819

Defined Benefit Plan, Amounts Recognized in Regulatory Assets

402,297

329,743

Projected benefit obligation

(876,308)

(747,460)

Defined Benefit Plan, Plans with Benefit Obligations in Excess of Plan Assets, Aggregate Fair Value of Plan Assets

481,077

432,233

(750,263)

(635,541)

Weighted-Average Actuarial Assumptions used to Determine Net Periodic Benefit Obligation:

481,077

432,233

Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase

4.50%

5.35%

4.00%

4.00%

Pension Benefits [Member] | Wolf Creek [Member]

131,460

111,033

4,957

4,144

3,643

7,370

6,941

6,401

(3,033)

(2,799)

20,642

12,141

^[1]

161,396

131,460

111,033

76,086

62,516

(2,578)

10,082

10,009

6,044

(2,790)

(2,556)

80,727

76,086

62,516

Amounts Recognized in Regulatory Assets Consist of:

(80,669)

(55,374)

(243)

(256)

Pension and Other Postretirement Defined Benefit Plans, Liabilities

(80,426)

(55,118)

(80,669)

(55,374)

Amounts Recognized in Regulatory Assets Consist of:

65,273

39,735

Defined Benefit Plan, Amounts Recognized in Regulatory Assets

65,304

39,834

Projected benefit obligation

161,396

131,460

Defined Benefit Plan, Plans with Benefit Obligations in Excess of Plan Assets, Aggregate Fair Value of Plan Assets

80,727

76,086

128,633

106,684

Weighted-Average Actuarial Assumptions used to Determine Net Periodic Benefit Obligation:

80,727

76,086

Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase

4.55%

5.45%

4.00%

4.00%

Post-Retirement Benefits [Member]

137,759

128,998

1,803

1,526

1,529

6,793

7,083

6,917

(3,390)

(3,292)

10,114

11,090

5,246

7,950

750

^[1]

150,078

137,759

128,998

86,984

74,114

(174)

9,849

10,793

10,512

3,244

3,147

9,739

10,955

91,858

86,984

74,114

Amounts Recognized in Regulatory Assets Consist of:

(58,220)

(50,775)

115

Pension and Other Postretirement Defined Benefit Plans, Liabilities

58,105

50,684

(58,220)

(50,775)

Amounts Recognized in Regulatory Assets Consist of:

18,178

8,458

18,991

17,065

Defined Benefit Plan, Amounts Recognized in Regulatory Assets

4,236

8,148

41,405

33,671

(150,078)

(137,759)

Weighted-Average Actuarial Assumptions used to Determine Net Periodic Benefit Obligation:

91,858

86,984

Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase

4.25%

5.00%

0.00%

0.00%

Post-Retirement Benefits [Member] | Wolf Creek [Member]

10,144

9,574

165

179

188

458

519

538

614

554

(979)

(1,045)

(360)

363

^[1]

10,129

10,144

9,574

369

614

(979)

Amounts Recognized in Regulatory Assets Consist of:

(10,125)

(10,144)

(609)

(689)

Pension and Other Postretirement Defined Benefit Plans, Liabilities

(9,516)

(9,455)

(10,125)

(10,144)

Amounts Recognized in Regulatory Assets Consist of:

3,208

3,796

Defined Benefit Plan, Amounts Recognized in Regulatory Assets

115

3,266

3,911

10,129

10,144

Weighted-Average Actuarial Assumptions used to Determine Net Periodic Benefit Obligation:

$ 4

$ 0

Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase

4.10%

4.90%

0.00%

0.00%

[1]	Other includes the $9.7 million reclassification of a contractual obligation related to the legal settlement with a former executive officer and $0.8 million of proceeds received as a result of the Early Retiree Reinsurance Program.

Wolf Creek Employee Benefit Plans Wolf Creek Employee Benefit Plans (Additional Information on Pension And Post-Retirement Benefit Plans) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Pension Benefits [Member]
Components of Net Periodic Cost (Benefit):
Service cost	$ 16,076	$ 13,926	$ 12,882
Interest cost	40,045	39,391	38,162
Expected return on plan assets	(31,087)	(38,384)	(37,826)
Transition obligation, net	0	0	0
Prior service costs	1,213	2,729	2,668
Actuarial loss, net	23,659	17,183	14,263
Net periodic cost before regulatory adjustment	49,906	34,845	30,149
Regulatory adjustment	(22,098)	(12,167)	(9,188)
Net periodic cost	27,808	22,678	20,961
Other Changes in Plan Assets and Benefit Obligations Recognized in Regulatory Assets:
Current year actuarial (gain)/loss	97,429	65,690	(34,610)
Amortization of actuarial loss	(23,659)	(17,183)	(14,263)
Amortization of prior service costs	(1,213)	(2,729)	(2,668)
Amortization of transition obligation	0	0	0
Total recognized in regulatory assets	72,557	46,454	(51,493)
Total recognized in net periodic cost and regulatory assets	100,365	69,132	(30,532)
Weighted-Average Actuarial Assumptions used to Determine Net Periodic Cost (Benefit):
Discount rate	5.35%	5.95%	6.10%
Expected long-term return on plan assets	6.50%	8.25%	8.25%
Compensation rate increase	4.00%	4.00%	4.00%
Pension Benefits [Member] \| Wolf Creek [Member]
Components of Net Periodic Cost (Benefit):
Service cost	4,957	4,144	3,643
Interest cost	7,370	6,941	6,401
Expected return on plan assets	(5,904)	(5,453)	(4,976)
Transition obligation, net	52	57	57
Prior service costs	16	29	43
Actuarial loss, net	3,586	2,636	2,538
Net periodic cost before regulatory adjustment	10,077	8,354	7,706
Regulatory adjustment	(2,546)	(1,498)	(945)
Net periodic cost	7,531	6,856	6,761
Other Changes in Plan Assets and Benefit Obligations Recognized in Regulatory Assets:
Current year actuarial (gain)/loss	29,124	7,514	(3,407)
Amortization of actuarial loss	(3,586)	(2,636)	(2,538)
Amortization of prior service costs	(16)	(29)	(43)
Amortization of transition obligation	(52)	(57)	(57)
Total recognized in regulatory assets	25,470	4,792	(6,045)
Total recognized in net periodic cost and regulatory assets	33,001	11,648	716
Weighted-Average Actuarial Assumptions used to Determine Net Periodic Cost (Benefit):
Discount rate	5.45%	6.05%	6.15%
Expected long-term return on plan assets	7.50%	8.00%	8.00%
Compensation rate increase	4.00%	4.00%	4.00%
Post-Retirement Benefits [Member]
Components of Net Periodic Cost (Benefit):
Service cost	1,803	1,526	1,529
Interest cost	6,793	7,083	6,917
Expected return on plan assets	(5,002)	(5,197)	(4,756)
Transition obligation, net	3,911	3,912	3,912
Prior service costs	2,524	2,154	1,580
Actuarial loss, net	702	321	(38)
Net periodic cost before regulatory adjustment	10,731	9,799	9,144
Regulatory adjustment	1,344	1,868	2,280
Net periodic cost	12,075	11,667	11,424
Other Changes in Plan Assets and Benefit Obligations Recognized in Regulatory Assets:
Current year actuarial (gain)/loss	10,421	3,298	(26,205)
Amortization of actuarial loss	(702)	(321)	38
Amortization of prior service costs	(2,524)	(2,154)	(1,580)
Amortization of transition obligation	(3,911)	(3,912)	(3,912)
Total recognized in regulatory assets	7,735	(3,089)	(25,063)
Total recognized in net periodic cost and regulatory assets	19,810	8,578	(13,639)
Weighted-Average Actuarial Assumptions used to Determine Net Periodic Cost (Benefit):
Discount rate	5.00%	5.65%	6.05%
Expected long-term return on plan assets	6.00%	7.75%	7.75%
Compensation rate increase	0.00%	0.00%	0.00%
Post-Retirement Benefits [Member] \| Wolf Creek [Member]
Components of Net Periodic Cost (Benefit):
Service cost	165	179	188
Interest cost	458	519	538
Expected return on plan assets	0	0	0
Transition obligation, net	58	58	58
Prior service costs	0	0	0
Actuarial loss, net	227	276	257
Net periodic cost before regulatory adjustment	908	1,032	1,041
Regulatory adjustment	0	0	0
Net periodic cost	908	1,032	1,041
Other Changes in Plan Assets and Benefit Obligations Recognized in Regulatory Assets:
Current year actuarial (gain)/loss	(360)	363	708
Amortization of actuarial loss	(227)	(276)	(257)
Amortization of prior service costs	0	0	0
Amortization of transition obligation	(58)	(58)	(58)
Total recognized in regulatory assets	(645)	29	393
Total recognized in net periodic cost and regulatory assets	$ 263	$ 1,061	$ 1,434
Weighted-Average Actuarial Assumptions used to Determine Net Periodic Cost (Benefit):
Discount rate	4.90%	5.50%	6.05%
Expected long-term return on plan assets	0.00%	0.00%	0.00%
Compensation rate increase	0.00%	0.00%	0.00%

Wolf Creek Employee Benefit Plans Wolf Creek Employee Benefit Plans (Estimated Amounts From Regulatory Assets Into Net Periodic Cost in 2012) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011
Pension Benefits [Member]
Actuarial loss	$ 32,782
Prior service cost	613
Transition obligation	0
Estimated Future Change in Regulatory Assets, Pension and Other Postretirement Benefit Plans, Adjustment, before Tax	33,395
Pension Benefits [Member] \| Wolf Creek [Member]
Actuarial loss	5,368
Prior service cost	6
Transition obligation	0
Estimated Future Change in Regulatory Assets, Pension and Other Postretirement Benefit Plans, Adjustment, before Tax	5,374
Post-Retirement Benefits [Member]
Actuarial loss	1,509
Prior service cost	2,524
Transition obligation	3,911
Estimated Future Change in Regulatory Assets, Pension and Other Postretirement Benefit Plans, Adjustment, before Tax	7,944
Post-Retirement Benefits [Member] \| Wolf Creek [Member]
Actuarial loss	233
Prior service cost	0
Transition obligation	58
Estimated Future Change in Regulatory Assets, Pension and Other Postretirement Benefit Plans, Adjustment, before Tax	$ 291

Wolf Creek Employee Benefit Plans Wolf Creek Employee Benefit Plans (Assumed Annual Health Care Cost Growth Rates) (Details)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Health care cost trend rate assumed for next year	8.00%	8.00%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate)	5.00%	5.00%
Year that the rate reaches the ultimate trend rate	2018	2018
Wolf Creek [Member]
Health care cost trend rate assumed for next year	8.00%	8.00%
Rate to which the cost trend rate is assumed to decline (the ultimate trend rate)	5.00%	5.00%
Year that the rate reaches the ultimate trend rate	2018	2018

+ References+ Details

Wolf Creek Employee Benefit Plans Wolf Creek Employee Benefit Plans (One Percentage Change In Assumed Health Care Cost Growth Rates Effects) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011
Effect on total of service and interest cost from one-percentage-point increase	$ 69
Effect on total of service and interest cost from one-percentage-point decrease	(65)
Effect on post-retirement benefit obligation from one-percentage-point increase	1,465
Effect on post-retirement benefit obligation from one-percentage-point decrease	(1,362)
Wolf Creek [Member]
Effect on total of service and interest cost from one-percentage-point increase	(8)
Effect on total of service and interest cost from one-percentage-point decrease	8
Effect on post-retirement benefit obligation from one-percentage-point increase	(107)
Effect on post-retirement benefit obligation from one-percentage-point decrease	$ 103

Wolf Creek Employee Benefit Plans Wolf Creek Employee Benefit Plans (Fair Value of Plan Assets) (Details) (Wolf Creek [Member], USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Fair value of pension plan assets	$ 80,727	$ 76,086
Level 1
Fair value of pension plan assets	44,808	43,848
Level 2
Fair value of pension plan assets	32,289	29,078
Level 3
Fair value of pension plan assets	3,630	3,160
Domestic Equity Securities [Member]
Fair value of pension plan assets	30,753	31,492
Domestic Equity Securities [Member] \| Level 1
Fair value of pension plan assets	30,753	31,492
Domestic Equity Securities [Member] \| Level 2
Fair value of pension plan assets	0	0
Domestic Equity Securities [Member] \| Level 3
Fair value of pension plan assets	0	0
International Equity Securities [Member]
Fair value of pension plan assets	18,023	18,633
International Equity Securities [Member] \| Level 1
Fair value of pension plan assets	9,953	9,036
International Equity Securities [Member] \| Level 2
Fair value of pension plan assets	8,070	9,597
International Equity Securities [Member] \| Level 3
Fair value of pension plan assets	0	0
Core Bonds [Member]
Fair value of pension plan assets	17,877	14,156
Core Bonds [Member] \| Level 1
Fair value of pension plan assets	0	0
Core Bonds [Member] \| Level 2
Fair value of pension plan assets	17,877	14,156
Core Bonds [Member] \| Level 3
Fair value of pension plan assets	0	0
High-yield bonds
Fair value of pension plan assets	4,102	3,319
High-yield bonds \| Level 1
Fair value of pension plan assets	4,102	3,319
High-yield bonds \| Level 2
Fair value of pension plan assets	0	0
High-yield bonds \| Level 3
Fair value of pension plan assets	0	0
Real Estate [Member]
Fair value of pension plan assets	3,630	3,160
Real Estate [Member] \| Level 1
Fair value of pension plan assets	0	0
Real Estate [Member] \| Level 2
Fair value of pension plan assets	0	0
Real Estate [Member] \| Level 3
Fair value of pension plan assets	3,630	3,160
Commodities
Fair value of pension plan assets	4,377	4,558
Commodities \| Level 1
Fair value of pension plan assets	0	0
Commodities \| Level 2
Fair value of pension plan assets	4,377	4,558
Commodities \| Level 3
Fair value of pension plan assets	0	0
Commodities
Fair value of pension plan assets	1,965	768
Commodities \| Level 1
Fair value of pension plan assets	0	1
Commodities \| Level 2
Fair value of pension plan assets	1,965	767
Commodities \| Level 3
Fair value of pension plan assets	$ 0	$ 0

+ References+ Details

Wolf Creek Employee Benefit Plans Wolf Creek Employee Benefit Plans (Changes in Level 3 Plan Assets Measured at Fair Value on a Recurring Basis) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at period start		$ 15,948
Purchases, issuances and settlements		(6,583)
Balance at period end	20,478	18,036
Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at period start	54,950	46,347
Actual gain (loss) on plan assets relating to assets still held at the reporting date	4,514	(907)
Actual gain (loss) on plan assets relating to assets sold during the period	(49)	4,248
Purchases, issuances and settlements	15,524	5,262
Balance at period end	74,939	54,950
Real Estate [Member] \| Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at period start	16,411	14,518
Actual gain (loss) on plan assets relating to assets still held at the reporting date	2,652	2,117
Actual gain (loss) on plan assets relating to assets sold during the period	(49)	(77)
Purchases, issuances and settlements	(166)	(147)
Balance at period end	18,848	16,411
Real Estate [Member] \| Level 3 \| Wolf Creek [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at period start	3,160	2,416
Actual gain (loss) on plan assets relating to assets still held at the reporting date	500	393
Actual gain (loss) on plan assets relating to assets sold during the period	2	(2)
Purchases, issuances and settlements	(32)	353
Balance at period end	$ 3,630	$ 3,160

Wolf Creek Employee Benefit Plans Wolf Creek Employee Benefit Plans (Expected Cash Flows Related To Pension and Post-Retirement Benefit Plans) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011
To/(From) Trust \| Pension Benefits [Member]
Expected contributions:
2012	$ 57.4
Expected benefit payments:
2012	(29.3)
2013	(31.1)
2014	(33.1)
2015	(35.1)
2016	(37.8)
2017 - 2021	(231.9)
To/(From) Trust \| Pension Benefits [Member] \| Wolf Creek [Member]
Expected contributions:
2012	11.5
Expected benefit payments:
2012	(3.4)
2013	(3.9)
2014	(4.4)
2015	(5.1)
2016	(5.9)
2017 - 2021	(43.3)
To/(From) Trust \| Post-Retirement Benefits [Member]
Expected contributions:
2012	10.8
Expected benefit payments:
2012	(7.9)
2013	(8.3)
2014	(8.7)
2015	(9.3)
2016	(9.6)
2017 - 2021	(51.3)
To/(From) Trust \| Post-Retirement Benefits [Member] \| Wolf Creek [Member]
Expected contributions:
2012	0
Expected benefit payments:
2012	0
2013	0
2014	0
2015	0
2016	0
2017 - 2021	0
To/(From) Company Assets \| Pension Benefits [Member]
Expected contributions:
2012	2.7
Expected benefit payments:
2012	(2.7)
2013	(2.7)
2014	(2.8)
2015	(2.8)
2016	(2.8)
2017 - 2021	(13.2)
To/(From) Company Assets \| Pension Benefits [Member] \| Wolf Creek [Member]
Expected contributions:
2012	0.2
Expected benefit payments:
2012	(0.2)
2013	(0.2)
2014	(0.2)
2015	(0.2)
2016	(0.2)
2017 - 2021	(1.0)
To/(From) Company Assets \| Post-Retirement Benefits [Member]
Expected contributions:
2012	0.1
Expected benefit payments:
2012	(0.1)
2013	(0.1)
2014	(0.1)
2015	(0.1)
2016	(0.1)
2017 - 2021	(0.7)
To/(From) Company Assets \| Post-Retirement Benefits [Member] \| Wolf Creek [Member]
Expected contributions:
2012	0.6
Expected benefit payments:
2012	(0.6)
2013	(0.7)
2014	(0.7)
2015	(0.7)
2016	(0.8)
2017 - 2021	$ (4.0)

Wolf Creek Employee Benefit Plans (Details Textual) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011 bonds Y	Dec. 31, 2010	Dec. 31, 2009
Defined Contribution Plan, Cost Recognized	$ 7.0	$ 7.4	$ 6.5
Number of contributing bonds used as basis for interest rate tield curve	500
Maturities on contributing bonds used as basis for interest rate tield curve, minimum	0
Maturities on contributing bonds used as basis for interest rate tield curve, maximum	30
KGE [Member]
Subsidiary's interest, percentage	47.00%
Wolf Creek [Member]
Defined Contribution Plan, Cost Recognized	$ 1.3	$ 1.1	$ 1.1
Number of contributing bonds used as basis for interest rate tield curve	500
Maturities on contributing bonds used as basis for interest rate tield curve, minimum	0
Maturities on contributing bonds used as basis for interest rate tield curve, maximum	30
Maximum allocation to international equity securities	25.00%
Maximum allocation to the common stock of one corporation	5.00%
Maximum allocation to any one corporation's outstanding common stock	1.00%
Target allocation of plan assets to international equity securities	22.00%
Target allocation of plan assets to domestic equity securities	43.00%
Target allocation of plan assets to debt securities	25.00%
Target allocation of plan assets to real estate securities	5.00%
Target allocation of plan assets to commodity investments	5.00%

Commitments And Contingencies (Details) (USD $)	0 Months Ended		1 Months Ended	5 Months Ended	9 Months Ended	12 Months Ended
Commitments And Contingencies (Details) (USD $)	Aug. 19, 2011	Feb. 23, 2011	Jun. 30, 2010	May 31, 2010	Sep. 30, 2011	Dec. 31, 2011 MW facilities agreements Y sites Criteria_Pollutants States phases	Dec. 31, 2010	Dec. 31, 2009
Commitments And Contingencies [Line Items]
Unexpended Commitments						$ 560,600,000
Aggregate Amount of Required Payments [Abstract]
2012						263,076,000
2013						72,121,000
2014						54,113,000
Thereafter						21,491,000
Total amount committed						410,801,000
Federal Clean Air Act [Abstract]
Number of National Ambient Air Quality Standards						6
Review period interval by the EPA						5
Environmental Projects [Abstract]
Environmental costs					600,000,000	600,000,000
Environmental upgrades of jointly owned utility plant	1,200,000,000	1,200,000,000				1,200,000,000
Air Emissions [Abstract]
Number of states required to comply with regulations						28
Number of states required to comply with seasonal regulations						5
Renewable Energy Standard [Abstract]
Capacity Of Qualifying Wind Generation Facilities						300
Supply agreement duration, years						20
Future Capacity Of Wind Generation Facilities						370
Number of sites with remediation liability						7
Number of sites shared for remediation liability						5
Remediation liability						3,800,000
Maximum Environmental Remediation Liability For Former Missouri Manufactured Gas Sites			2,500,000	7,500,000
EPA Lawsuit [Abstract]
Preliminary estimate of the cost of selective catalytic reduction (SCR)						240,000,000
FERC Investigation [Abstract]
Loss Contingency, Estimate of Possible Loss						500,000
Nuclear Decommissioning [Abstract]
Site study frequency						3
Number of nuclear decommissioning phases						2
Estimated Decommissioning Costs						296,200,000
Previously Estimated Decommissioning Costs						279,000,000
Decommissioning Fund Investments						3,200,000	3,100,000	2,900,000
Total Nuclear Decommissioning Trust						130,270,000	126,990,000
Fee for Future Disposal						3,100,000	4,000,000	3,700,000
Number of insurance types for nuclear insurance						4
Nuclear insurance						3,200,000,000
Nuclear Liability Insurance - Full Limit of Public Liability						12,600,000,000
Nuclear Liability Insurance - Maximum Available Commercial Insurance						375,000,000
Nuclear Liability Insurance - Industry-Wide Retrospective Assessment Program						12,200,000,000
Nuclear Liability Insurance - Owners of Wolf Creek Subject to Insurance Amount Maximum						117,500,000
Nuclear Liability Insurance - Westar Portion of Wolf Creek Subject to Insurance Amount Maximum						55,200,000
Nuclear Liability Insurance - Owners of Wolf Creek Subject to Insurance Amount, Per Incident						17,500,000
Nuclear Liability Insurance - Westar Portion of Wolf Creek Subject to Insurance Amount, Per Incident						8,200,000
Nuclear Liability Insurance - Owners Property Insurance, Maximum						2,800,000,000
Nuclear Liability Insurance - Westar Portion of Owners Property Insurance, Maximum						1,300,000,000
Nuclear Liability Insurance - Owners Accidental Nuclear Outage Insurance, Maximum						30,900,000
Nuclear Liability Insurance - Westar Portion of Owners Accidental Nuclear Outage Insurance, Maximum						14,500,000
Number of Wind Generation Facilities						2
Capacity of wind generation facilities, megawatts						146
Agreements with Third Party						2
Future Purchase Cost, Year One						31,700,000
Future Purchase Cost, Year Two						68,200,000
2011 Through 2015 Generation Capacity Peak Demand [Member]
Renewable Energy Standard [Abstract]
Renewable energy generation capacity, percentage						10.00%
2016 Through 2019 Generation Capacity Peak Demand [Member]
Renewable Energy Standard [Abstract]
Renewable energy generation capacity, percentage						15.00%
2020 And Thereafter Generation Capacity Peak Demand [Member]
Renewable Energy Standard [Abstract]
Renewable energy generation capacity, percentage						20.00%
Preliminary Unjust Profits [Member]
FERC Investigation [Abstract]
Unjust profits through alleged activities						14,300,000
Revised Unjust Profits [Member]
FERC Investigation [Abstract]
Unjust profits through alleged activities						3,000,000
Alleged Transmission Service Costs [Member]
FERC Investigation [Abstract]
Unjust profits through alleged activities						3,200,000
Further Revised Unjust Profits [Member]
FERC Investigation [Abstract]
Unjust profits through alleged activities						900,000
Potential GHGE Missions Restrictions 1 [Member]
Greenhouse Gases [Abstract]
GHG emission						75,000
Potential GHGE Missions Restrictions 2 [Member]
Greenhouse Gases [Abstract]
GHG emission						100,000
Revised Alleged Transmission Service Costs [Member]
FERC Investigation [Abstract]
Unjust profits through alleged activities						800,000
Minimum [Member]
Air Emissions [Abstract]
Period to Comply With Regulations						4 years
Period to submit implementation plan						12
Maximum [Member]
Air Emissions [Abstract]
Period to Comply With Regulations						5 years
Period to submit implementation plan						18
Uranium Concentrates [Member]
Nuclear Decommissioning [Abstract]
Long-term Purchase Commitment, Amount						38,400,000
Conversion [Member]
Nuclear Decommissioning [Abstract]
Long-term Purchase Commitment, Amount						5,800,000
Enrichment [Member]
Nuclear Decommissioning [Abstract]
Long-term Purchase Commitment, Amount						116,100,000
Fabrication [Member]
Nuclear Decommissioning [Abstract]
Long-term Purchase Commitment, Amount						43,000,000
Coal and Coal Transportation [Member]
Nuclear Decommissioning [Abstract]
Long-term Purchase Commitment, Amount						886,000,000
Natural Gas Transportation [Member]
Nuclear Decommissioning [Abstract]
Long-term Purchase Commitment, Amount						$ 145,900,000

Asset Retirement Obligations (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Beginning ARO	$ 125,999	$ 119,519
Liabilities incurred	0	0
Liabilities settled	(1,027)	(738)
Accretion expense	7,623	7,218
Ending ARO	142,508	125,999
KGE ownership share	47.00%
Regulatory liability	271,387	267,074
Increase in nuclear decommissioning ARO liability	9,913	0
Costs of Plant Assets Disposal Not Legal Retirement Obligations [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Regulatory liability	$ 82,300	$ 70,300

The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.

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Variable Interest Entity [Line Items]

Amount of accretion expense recognized during the period that is associated with an asset retirement obligation. Accretion expense measures and incorporates changes due to the passage of time into the carrying amount of the liability.

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Legal Proceedings (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended
	Jul. 31, 2011	May 31, 2011	Sep. 30, 2011	Dec. 31, 2010
Legal Proceedings [Abstract]
Employee related accrued liabilities				$ 80.6
Legal fees and expenses				8.3
Settlements of employee related accrued liabilities		21.0
Settlements of legal fees and expenses	3.1	5.3
Settlements of employee related contractual obligation and other claims	36.0
Reversal of previously accrued liabilities			$ 22.0

Common and Preferred Stock (Details) (USD $)	0 Months Ended	12 Months Ended
Common and Preferred Stock (Details) (USD $)	Nov. 17, 2011	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Nov. 30, 2010 M	Apr. 30, 2010 Y
Common Stock [Line Items]
Common stock, authorized		275,000,000	150,000,000
Common stock, issued	8,500,000	125,698,396	112,128,068
Proceeds from Issuance or Sale of Equity	$ 197,300,000	$ 294,942,000	$ 54,651,000	$ 4,587,000
Shares Borrowed Under Forward Contracts					8,500,000
Commissions Paid, Percenatage of Sales Price of Shares Sold					3.50%	1.00%
Forward Contract Indexed to Issuer's Equity, Settlement Period					18	1
Sale of Stock, Price Per Share					$ 25.54
Forward Sale Agreement, Period						3
Forward Sale Agreement, Maximum Amount Authorized						500,000,000
Forward Sale Agreement, Maximum Shares Authorized						22,000,000
Direct Stock Purchase Plan And Other Stock-Based Plans [Member]
Common Stock [Line Items]
Shares, Issued		800,000	700,000	800,000
DSPP [Member]
Common Stock [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant		2,000,000	2,600,000
Forward Sale Agreement Entered In April 2010 [Member]
Common Stock [Line Items]
Common stock, issued		4,200,000	1,200,000
Proceeds from Issuance or Sale of Equity		$ 91,900,000	$ 26,400,000
Shares Borrowed Under Forward Contracts						5,400,000
Base Allotment [Member]
Common Stock [Line Items]
Shares Borrowed Under Forward Contracts					7,500,000
Over Allotment Option [Member]
Common Stock [Line Items]
Shares Borrowed Under Forward Contracts					1,000,000

Common and Preferred Stock (Details 2) (USD $)	12 Months Ended
Common and Preferred Stock (Details 2) (USD $)	Dec. 31, 2011 M	Dec. 31, 2010
Review Period Interval for Dividend Payment	12
Temporary Equity, Shares Outstanding	214,363	214,363
Preferred Stock, Value, Issued	$ 21,436,000	$ 21,436,000
Capital Required for Capital Adequacy	10,500,000
Redeemable Preferred Stock [Member]
Preferred Stock Redemption Premium	1,131,000
Temporary Equity, Redemption Value	22,567,000
Temporary Equity, Shares Outstanding	214,363,000
Preferred Stock, Value, Issued		21,436,000
Redeemable Preferred Stock Rate One [Member]
Preferred Stock, Call Price	1.08
Preferred Stock Redemption Premium	973,000
Temporary Equity, Redemption Value	13,134,000
Preferred Stock, Dividend Rate, Percentage	4.50%
Temporary Equity, Shares Outstanding	121,613,000
Preferred Stock, Value, Issued		12,161,000
Redeemable Preferred Stock Rate Two [Member]
Preferred Stock, Call Price	1.015
Preferred Stock Redemption Premium	82,000
Temporary Equity, Redemption Value	5,579,000
Preferred Stock, Dividend Rate, Percentage	4.25%
Temporary Equity, Shares Outstanding	54,970,000
Preferred Stock, Value, Issued		5,497,000
Redeemable Preferred Stock Rate Three [Member]
Preferred Stock, Call Price	1.02
Preferred Stock Redemption Premium	76,000
Temporary Equity, Redemption Value	3,854,000
Preferred Stock, Dividend Rate, Percentage	5.00%
Temporary Equity, Shares Outstanding	37,780,000
Preferred Stock, Value, Issued		$ 3,778,000
Minimum [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Investment Redemption, Notice Period	30
Maximum [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Investment Redemption, Notice Period	60
Dividends Paid Condition One [Member] \| Minimum [Member]
Payment as Percentage of Net Income	50.00%
Dividends Paid Condition Two [Member] \| Minimum [Member]
Capitalization Ratio	20.00%
Dividends Paid Condition Two [Member] \| Maximum [Member]
Capitalization Ratio	25.00%
Payment as Percentage of Net Income	75.00%
Dividends Restrictions Condition Three [Member]
Capitalization Ratio	25.00%

Variable Interest Entities (Assets And Liabilities In Relation To VIEs) (Details) (USD $)
In Thousands, unless otherwise specified

Dec. 31, 2011

Dec. 31, 2010

$ 6,411,922

$ 5,964,439

1,046,090

861,065

Long-term debt of variable interest entities, net

77,437

^[1]

77,771

^[1]

2,491,109

2,490,871

Variable Interest Entity, Primary Beneficiary [Member]

Variable Interest Entity [Line Items]

333,494

345,037

4,915

^[2]

3,963

^[2]

28,114

30,155

Long-term debt of variable interest entities, net

4,448

^[1]

5,064

^[1]

$ 249,283

$ 278,162

[1]	Included in accrued interest on our consolidated balance sheets.
[2]	Included in long-term regulatory assets on our consolidated balance sheets.

Carrying value as of the balance sheet date of [accrued] interest payable on all forms of debt, including trade payables, that has been incurred and is unpaid. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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Leases (Details) (USD $) In Millions, unless otherwise specified	0 Months Ended	12 Months Ended
	Apr. 28, 2011	Dec. 31, 2011	Jun. 30, 2011
Leases [Line Items]
Lease Expiration Date	May 2039	May 2013 and November 2014
Capital lease			$ 40.0
Minimum [Member]
Leases [Line Items]
Lease term in years		1
Maximum [Member]
Leases [Line Items]
Lease term in years		20,000
Vehicles [Member] \| Minimum [Member]
Leases [Line Items]
Lease term in years		2
Vehicles [Member] \| Maximum [Member]
Leases [Line Items]
Lease term in years		8
Computer Equipment [Member] \| Minimum [Member]
Leases [Line Items]
Lease term in years		4
Computer Equipment [Member] \| Maximum [Member]
Leases [Line Items]
Lease term in years		5

Leases Leases (Operating Leases, Minimum Annual Rental Payments) (Details) (USD $)
In Thousands, unless otherwise specified

12 Months Ended

Dec. 31, 2011

Dec. 31, 2010

Dec. 31, 2009

Rental expense:

Rental expense

$ 17,577

$ 15,464

^[1]

$ 38,096

Future commitments:

16,247

13,919

11,820

9,721

8,393

17,520

Total future commitments

$ 77,620

[1]	In 2010, we began consolidating certain trusts that hold assets we lease as VIEs as discussed in Note 17, “Variable Interest Entities.” This eliminated the lease accounting we previously reported for these assets and, as a result, rental expense decreased significantly from 2009 to 2010.

Leases (Assets Recorded Under Capital Leases) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Leases [Line Items]
Accumulated amortization	$ (6,485)	$ (8,744)
Total capital leases	49,524	9,311
Vehicles [Member]
Leases [Line Items]
Capital leased assets gross	14,241	12,504
Computer Equipment [Member]
Leases [Line Items]
Capital leased assets gross	1,720	5,551
Power Supply Agreement [Member]
Leases [Line Items]
Capital leased assets gross	$ 40,048	$ 0

Property, plant, or equipment held under lease agreements classified as an asset.

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The total charge for the use of long-lived depreciable assets subject to a lease meeting the criteria for capitalization.

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Leases (Capital Leases, Minimum Annual Rental Payments) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011
Leases [Abstract]
2012	$ 5,452
2013	5,200
2014	5,203
2015	4,987
2016	4,127
Thereafter	67,830
Total future commitments	92,799
Amounts representing imputed interest	(43,275)
Present value of net minimum lease payments under capital leases	49,524
Less: current portion	2,471
Total long-term obligation under capital leases	$ 47,053

Discontinued Operations (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Discontinued operations, net of tax	$ 0	$ 0	$ 33,745
Other settlement costs	0	0	22,750
Protection One [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Other settlement costs			$ (22,800)

This element represents the overall income (loss) from a disposal group that is classified as a component of the entity, net of income tax, reported as a separate component of income before extraordinary items before deduction or consideration of the amount which may be allocable to noncontrolling interests, if any. Includes the following (net of tax): income (loss) from operations during the phase-out period, gain (loss) on disposal, provision (or any reversals of earlier provisions) for loss on disposal, and adjustments of a prior period gain (loss) on disposal.