Customer accounts receivable Trade Accounts Receivable [Member] Document Type Document Type Accounts, Notes, Loans and Financing Receivable by Receivable Type [Axis] Receivable Type [Axis] ICFR Auditor Attestation Flag ICFR Auditor Attestation Flag March 2019 ASR Agreement March 2019 ASR Agreement [Member] March 2019 ASR Agreement [Member] State and local obligations US States and Political Subdivisions Debt Securities [Member] COMPREHENSIVE INCOME Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract] Contributions to plans in next year Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year Nuclear fuel, net Nuclear Fuel [Member] Evergy Kansas South Inc Evergy Kansas South Inc [Member] Evergy Kansas South Inc [Member] COMMITMENTS AND CONTINGENCIES Commitments and Contingencies Disclosure [Text Block] Related Party [Axis] Related Party [Axis] Senior Notes Due 2025 EMW Senior Notes Series A due 2025 EMW [Member] Senior Notes Series A due 2025 EMW Nuclear decommissioning trust - equity securities Decommissioning Trust Assets - Equity [Member] Decommissioning Trust Assets - Equity [Member] Regulatory assets Regulatory Assets, Current PENSION PLANS AND POST-RETIREMENT BENEFITS Retirement Benefits [Text Block] Kansas state statutory income tax rate thru 2020 Kansas State Statutory Income Tax Rate Thru 2020 Kansas state statutory corporate income tax rate in effect thru 2020 Prairie Wind Transmission, LLC Prairie Wind Transmission, LLC [Member] Prairie Wind Transmission, LLC [Member] Level 3 Fair Value, Inputs, Level 3 [Member] Repurchase of common stock (in shares) Stock Repurchased During Period, Shares Net gain (loss) arising during period, net of tax Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, after Tax Decrease in net deferred income tax liabilities for revaluation of deferred income tax assets and liabilities in rate base Increase Decrease In Net Deferred Income Tax Liabilities For Revaluation Of Regulated Deferred Income Tax Assets And Liabilities Increase (decrease) in net deferred income tax liabilities for revaluation of regulated deferred income tax assets and liabilities Emerging markets bond fund Emerging Markets Bond Fund [Member] Emerging Markets Bond Fund [Member] Statistical Measurement [Domain] Statistical Measurement [Domain] LIABILITIES AND EQUITY Liabilities and Equity [Abstract] Distributions to shareholders of noncontrolling interests Noncontrolling Interest, Decrease from Distributions to Noncontrolling Interest Holders Changes in other liabilities Increase (Decrease) in Other Noncurrent Liabilities Deferred income taxes Deferred Income Tax Liabilities, Net Security Exchange Name Security Exchange Name Annual revenue increase (decrease) approved Public Utilities, Approved Rate Increase (Decrease), Amount Debt Instrument, debt to capitalization ratio (no more than) Debt Instrument, Covenant, Debt To Capitalization Ratio, Maximum Debt Instrument, Covenant, Debt to Capitalization Ratio, Maximum Proceeds from investment in corporate-owned life insurance Proceeds from investment in corporate-owned life insurance Proceeds from Life Insurance Policy Domestic Geographic Distribution, Domestic [Member] Proceeds from long-term debt Proceeds from Issuance of Long-term Debt INCOME FROM OPERATIONS Operating Income (Loss) Increase in Wholesale Revenues Increase in Wholesale Revenues Increase in Wholesale Revenues Total Current Liabilities Liabilities, Current Other Other Nonoperating Income (Expense), Other Other Nonoperating Income (Expense), Other Electric plant in service Electric Plant In Service [Member] Electric Plant In Service [Member] Reclassification out of Accumulated Other Comprehensive Income Reclassification out of Accumulated Other Comprehensive Income [Member] Prepaid expenses and other assets Prepaid Expense and Other Assets, Current International Geographic Distribution, Foreign [Member] Accounts receivable pledged as collateral Transfers Accounted for as Secured Borrowings, Assets, Carrying Amount CASH, CASH EQUIVALENTS AND RESTRICTED CASH: Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect [Abstract] Commitments and Contingencies (Note 10) Commitments and Contingencies Valuation allowance Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Percent Senior Notes Series C due 2036 EMW SeniorNotesSeriesCDue2036EMW [Member] Senior Notes Series C Due 2036 EMW Repurchase of common stock under repurchase plan Payments for Repurchase of Common Stock ASSETS Assets [Abstract] Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Investment, Name [Axis] Investment, Name [Axis] Accounting Policies [Abstract] Accounting Policies [Abstract] Nuclear decommissioning trust: Decommissioning Trust Assets [Member] Decommissioning Trust Assets [Member] Accrued taxes Taxes Payable, Current Entity Address, State or Province Entity Address, State or Province Due to Related Parties, Current Due to Related Parties, Current Accounts payable Accounts Payable, Current Income Earnings Per Share Reconciliation [Abstract] Missouri Public Service Commission MissouriPublicServiceCommission [Member] Information related to the Public Service Commission of the State of Missouri. Senior Notes Due 2021 Senior Notes Due 2021 [Member] Senior Notes Due 2021. Retained earnings Retained Earnings (Accumulated Deficit) Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items] Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Line Items] Right-of-use assets under operating leases Operating Lease, Right-of-Use Asset Net loss on derivative hedging instruments Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax Percentage of Bondable Property Allowed PercentageofBondablePropertyAllowed PercentageofBondablePropertyAllowed Transmission Electric Utility Customer Class Transmission [Member] Transmission customer class from which revenues are generated by the use of KCP&L's and GMO's transmission network by the SPP on behalf of other power providers [Member] EQUITY: Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Schedule of Fair Value of Assets and Liabilities Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Evergy Missouri West Evergy Missouri West Inc [Member] Evergy Missouri West Inc [Member] Accounts receivable pledged as collateral Accounts receivable pledged as collateral Increase Decrease In Accounts Receivable Pledged As Collateral The increase (decrease) during the reporting period in the amount due within one year (or one business cycle) from customers for the credit sale of goods and services where those amounts have been pledged as collateral. Customer [Axis] Customer [Axis] State Current State and Local Tax Expense (Benefit) Shares, Outstanding Beginning balance (in shares) Ending balance (in shares) Shares, Outstanding Plant to be retired, net Plant To Be Retired [Member] Plant To Be Retired [Member] Regulatory liabilities Regulatory Liability, Noncurrent U.S. Treasury US Treasury and Government [Member] Borrowings From Mid-November Through Mid-June Borrowings From Mid November Through Mid June [Member] Borrowings From Mid November Through Mid June [Member] Decrease in net deferred income tax liabilities for tax gross-up adjustment for ratemaking purposes due to tax reform Increase (Decrease) in Net Deferred Income Tax Liabilities For Tax Gross-Up Adjustment For Ratemaking Purposes Due To Tax Reform Increase (decrease) in net deferred income tax liabilities for tax gross-up adjustment for ratemaking purposes due to tax reform Derivative hedging activity Other Comprehensive Income (Loss), Net of Tax [Abstract] Common stock - par value (in dollars per share) Common Stock, Par or Stated Value Per Share Other Other Liabilities, Noncurrent Other investing activities Payments for (Proceeds from) Other Investing Activities Public Utilities, Recovery Mechanism's Sharing Percentage for Fuel Cost Public Utilities, Recovery Mechanism's Sharing Percentage for Fuel Cost Public Utilities, Recovery Mechanism's Sharing Percentage for Fuel Cost Federal tax credits Effective Income Tax Rate Reconciliation, Tax Credit, Other, Percent Stock compensation expense APIC, Share-based Payment Arrangement, Increase for Cost Recognition Related party transaction Related Party Transaction, Amounts of Transaction Total revenue from contracts with customers Revenue from Contract with Customer, Excluding Assessed Tax Measurement Frequency [Domain] Measurement Frequency [Domain] Inventory [Line Items] Inventory [Line Items] Schedule of Common Stock Repurchase Program Schedule of Repurchase Agreements [Table Text Block] Dividends Payable [Line Items] Dividends Payable [Line Items] Regulatory Liability [Domain] Regulatory Liability [Domain] Restriction on payment of dividends (at least) Restriction on Payment Of Dividends, Minimum Ratio Of Equity To Capitalization Restriction on Payment of Dividends, Minimum Ratio of Equity to Capitalization Contributions to plans remainder of year Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year Settlement and special termination benefits Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] Statement [Line Items] Statement [Line Items] Increase of Natural Gas and Purchased Power Costs, Gross Increase of Natural Gas and Purchased Power Costs, Gross Increase of Natural Gas and Purchased Power Costs, Gross Fixed income funds Fixed Income Funds [Member] Class of Stock [Domain] Class of Stock [Domain] BASIC AND DILUTED EARNINGS PER AVERAGE COMMON SHARE OUTSTANDING ATTRIBUTABLE TO EVERGY, INC. (see Note 1) Earnings Per Share, Basic and Diluted [Abstract] Debt instrument, term Debt Instrument, Term Accrued interest Interest Payable, Current Entity Voluntary Filers Entity Voluntary Filers Length of Settlement Fair Value, Investments, Entities that Calculate Net Asset Value, Settlement Term Fair Value, Investments, Entities that Calculate Net Asset Value, Settlement Term Regulatory Proceedings [Line Items] Public Utilities, General Disclosures [Line Items] Statement [Table] Statement [Table] Write-offs Accounts Receivable, Allowance for Credit Loss, Writeoff Interest cost Defined Benefit Plan, Interest Cost Statistical Measurement [Axis] Statistical Measurement [Axis] Due from (to) related parties Related Party Transaction, Due from (to) Related Party, Current Credit Facility [Axis] Credit Facility [Axis] Net deferred income taxes and credits Deferred Income Taxes and Tax Credits Federal or state tax rate change Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent Purchase power agreement Purchase Power Agreement [Member] Discloses the amount included in retail electric rates from customers in excess of costs incurred under purchase power agreements. Class of Warrant or Right, Exercise Price of Warrants or Rights Class of Warrant or Right, Exercise Price of Warrants or Rights Property, plant and equipment, adjustment Property, Plant And Equipment, Adjustment Property, Plant And Equipment, Adjustment Regulatory asset representing differences between pension and post retirement costs for GAAP and for ratemaking RegulatoryAssetLiabilityRepresentingDifferencesBetweenPensionAndPostRetirementCostsForGAAPAndForRatemaking Regulatory asset (liability) that represents the differences between pension and post-retirement costs under GAAP and pension and post-retirement costs for ratemaking that will be recovered or refunded in rates, as appropriate, over future periods. Earnings Per Share, Basic and Diluted Earnings Per Share, Basic and Diluted Annual transmissions revenue estimated amount of increase (decrease) over prior year Public Utilities Estimated Annual Transmissions Revenue Increase (Decrease) Over Prior Year Amount Public utilities, estimated annual transmissions revenue amount of increase (decrease) over prior year Entity Small Business Entity Small Business RSU With Performance Measures Restricted Stock Units With Performance Measures [Member] Restricted Stock Units With Performance Measures [Member] Principles of Consolidation Consolidation, Policy [Policy Text Block] 2018 MPSC OPC MECG Petition 2018MPSCOPCMECGPetition [Member] 2018 MPSC Petition filed by OPC MECG requesting an accounting authority order[Member] Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Compensation expense recognized APIC, Share-based Payment Arrangement, Restricted Stock Unit, Increase for Cost Recognition Prepaid expenses Prepaid Expense, Current Senior Notes Due 2043 EMW Senior Notes Series C due 2043 EMW [Member] Senior Notes Series C due 2043. Issuance of common stock Proceeds from Issuance of Common Stock Asset retirement obligations Asset Retirement Obligation, Current Share Repurchase Program [Domain] Share Repurchase Program [Domain] Pension and post-retirement costs Pension and Other Postretirement Plans Costs [Member] Other receivables Other Receivables, Gross, Current Amendment Flag Amendment Flag Schedule of Earnings Per Share, Basic and Diluted Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] 2021 KCC Winter Weather AAO 2021 KCC Winter Weather AAO [Member] 2021 KCC Winter Weather AAO ordered in February allowing costs to be recovered due to extreme weather conditions, and increases to purchased power cost. Long-term line of credit Long-term Line of Credit Reclassification to expenses, net of tax Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax Cash Flows from Operating Activities Net Cash Provided by (Used in) Operating Activities Accounts, Notes, Loans and Financing Receivable by Billing Status, Type [Axis] Billing Status, Type [Axis] Fuel and purchased power FuelAndPurchasedPower Amount of operating expense for fuel and purchased power used by regulated operation Entity Central Index Key Entity Central Index Key Related Party [Domain] Related Party [Domain] Measurement Frequency [Axis] Measurement Frequency [Axis] Master Credit Facility Line of Credit Facility, Current Borrowing Capacity Fuel inventory and supplies Increase (Decrease) In Energy Related Inventory Increase (Decrease) In Energy Related Inventory Number of reporting units Number of Reporting Units Related Party Transaction [Line Items] Related Party Transaction [Line Items] Income Taxes Payable Income Taxes Payable [Member] Income Taxes Payable [Member] Income tax expense from tax reform Income Tax Expense From Tax Reform, Total Income Tax Expense From Tax Reform, Total Schedule of Carrying Value and Fair Value of Debt Instruments Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block] Expected return on plan assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets Total nuclear decommissioning trust Decommissioning Fund Investments, Fair Value Fair Value Measurement [Domain] Fair Value Measurement [Domain] Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Table] Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Table] Increase of Natural Gas and Purchased Power Costs, Net Increase in Wholesale Revenues Increase of Natural Gas and Purchased Power Costs, Net Increase in Wholesale Revenues The amount of increase of Natural Gas and Purchased Power Costs, Net of the Increase in Wholesale Revenues. Senior Notes Senior Notes Senior Notes [Member] Letters of Credit Standby Letters of Credit [Member] Income taxes receivable Income Taxes Receivable, Current Amortization of nuclear fuel Amortization of Nuclear fuel The noncash expense, not otherwise specified in the taxonomy, charged against earnings in the period to allocate the cost of nuclear fuel over the operating cycle of the nuclear plant. Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Deferral InvestmentTaxCreditDeferral Investment Tax Credit Deferral 2018 Rate Case Proceedings 2018 Rate Case Proceedings [Member] 2018 Rate Case Proceedings [Member] Add: effect of dilutive securities (in shares) Weighted Average Number Diluted Shares Outstanding Adjustment Property, Plant and Equipment, Type [Axis] Long-Lived Tangible Asset [Axis] NAV, number of funds making distributions Fair Value, Investments, Entities That Calculate Net Asset Value, Number Of Funds Making Distributions Fair Value, Investments, Entities that Calculate Net Asset Value, Number Of Funds Making Distributions Intercompany allocations Defined Benefit Plans Intercompany Allocations Net Increase (decrease) in net periodic benefit costs related to intercompany Net allocations. Allowance for credit losses Allowance for credit losses Beginning balance January 1 Ending balance June 30 Accounts Receivable, Allowance for Credit Loss, Current Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Stock compensation Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-based Payment Arrangement, Percent September 2019 ASR Agreement September2019ASRAgreement [Member] September 2019 ASR Agreement [Member] Total electric retail Electric Utility Customer Class Total Electric Retail [Member] Total electric retail customer class from which revenues are generated by the regulated sale of electricity [Member] Non-cash financing transactions: Other Noncash Investing and Financing Items [Abstract] Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest [Member] Senior Notes Series Due 2022 EMW Senior Notes Series Due 2022 EMW [Member] Senior Notes Series Due 2022 EMW [Member] CASH FLOWS FROM (USED IN) FINANCING ACTIVITIES: Net Cash Provided by (Used in) Financing Activities [Abstract] Accumulated other comprehensive loss over the next twelve months Interest Rate Cash Flow Hedge Gain (Loss) to be Reclassified During Next 12 Months, Net Dividends Payable [Table] Dividends Payable [Table] Federal Current Federal Tax Expense (Benefit) Regulatory adjustment Defined Benefit Plan Regulatory Adjustment Net Increase (decrease) in net periodic benefit costs related to regulatory adjustments Net. Stockholders' Equity Note [Abstract] Stockholders' Equity Note [Abstract] Notional amount Derivative, Notional Amount Sale of securities - trusts Proceeds from Decommissioning Trust Fund Assets Decrease in unamortized investment tax credits Increase Decrease In Unamortized Investment Tax Credits Increase (decrease) in unamortized investment tax credits Collateralized note payable Transfers Accounted for as Secured Borrowings, Associated Liabilities, Carrying Amount Line of Credit Facility [Table] Line of Credit Facility [Table] Other Other Assets, Noncurrent Evergy Transmission Company LLC Evergy Transmission Company LLC [Member] Evergy Transmission Company LLC [Member] Issuance of stock, net of issuance costs Stock Issued During Period, Value, New Issues TOTAL ASSETS Assets RELATED PARTY TRANSACTIONS AND RELATIONSHIPS Related Party Transactions Disclosure [Text Block] Schedule of Defined Benefit Plan, Plan with Projected Benefit Obligation in Excess of Plan Assets Defined Benefit Plan, Plan with Projected Benefit Obligation in Excess of Plan Assets [Table Text Block] Unearned compensation UnearnedCompensation [Abstract] UnearnedCompensation Restricted net assets of subsidiaries Amount of Restricted Net Assets for Consolidated and Unconsolidated Subsidiaries Schedule of Net Funded Status Schedule of Net Funded Status [Table Text Block] Foreign governments Debt Security, Government, Non-US [Member] Senior Notes Series A due 2031 EMW SeniorNotesSeriesADue2031EMW [Member] Senior Notes Series A due 2031 EMW Title of 12(b) Security Title of 12(b) Security Public Utilities, Regulatory Proceeding [Axis] Public Utilities, Regulatory Proceeding [Axis] Prior service cost Defined Benefit Plan, Amortization of Prior Service Cost (Credit) Subsidiary of Common Parent Subsidiary of Common Parent [Member] Senior Notes Due 2029 Evergy Senior Notes Due 2029 Evergy [Member] Senior Notes Due 2029 Evergy [Member] Subsequent Event Type [Axis] Subsequent Event Type [Axis] Antidilutive Securities [Axis] Antidilutive Securities [Axis] Geographic Distribution [Axis] Geographic Distribution [Axis] Reclassification out of Accumulated Other Comprehensive Income [Axis] Reclassification out of Accumulated Other Comprehensive Income [Axis] Payments for asset retirement obligations Payments For Asset Retirement Obligations Payments For Asset Retirement Obligations Interest expense Interest Expense Number of shares authorized to be repurchased (in shares) Stock Repurchase Program, Number of Shares Authorized to be Repurchased Other Stockholders' Equity, Other Stockholders' Equity, Other Schedule of Costs of Retirement Plans Schedule of Costs of Retirement Plans [Table Text Block] Schedule of Components of Income Tax Expense (Benefit) Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Long-Term debt fair value adjustment Long-TermDebtFairValueAdjustment [Member] Long-Term debt fair value adjustment recorded in association with the merger. Income Tax Contingency [Line Items] Income Tax Contingency [Line Items] Retirement Plan Type [Axis] Retirement Plan Type [Axis] Public Utilities, Recovery Mechanism Percent for Fuel Cost Public Utilities, Recovery Mechanism Percent for Fuel Cost Public Utilities, Recovery Mechanism Percent for Fuel Cost Schedule of Related Party Transactions, by Related Party [Table] Schedule of Related Party Transactions, by Related Party [Table] Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Level 1 Fair Value, Inputs, Level 1 [Member] Regulated Operations [Abstract] Regulated Operations [Abstract] Equity Securities - Fifth Fund Equity Securities - Fifth Fund [Member] Equity Securities - Fifth Fund [Member] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Loss on derivative hedging instruments Other comprehensive loss Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Accounts payable Increase (Decrease) in Accounts Payable Regulatory Agency [Axis] Regulatory Agency [Axis] Summary of Operating Loss Carryforwards Summary of Operating Loss Carryforwards [Table Text Block] Debt Instrument [Axis] Debt Instrument [Axis] Transmission delivery charge Transmission Delivery Charge [Member] Transmission Delivery Charge [Member] Schedule of Other Nonoperating Income (Expense) Schedule of Other Nonoperating Income (Expense) [Table Text Block] Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Asset Class [Axis] Asset Class [Axis] Adjustments to reconcile income to net cash from operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Customer accounts receivable Accounts Receivable, before Allowance for Credit Loss, Current Revenue from Contract with Customer [Abstract] Revenue from Contract with Customer [Abstract] OTHER ASSETS: Investments And Other Assets [Abstract] Entity Information [Line Items] Entity Information [Line Items] Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] June 2019 ASR Agreement June 2019 ASR Agreement [Member] June 2019 ASR Agreement [Member] Cash Borrowings Cash Borrowings Revolving Credit Facility [Member] Short-term Debt [Line Items] Short-term Debt [Line Items] Issuance of stock compensation and reinvested dividends, net of tax withholding Stock Issued During Period, Value, Dividend Reinvestment Plan And Share-Based Compensation Net Stock Issued During Period, Value, Dividend Reinvestment Plan And Share-Based Compensation Net Cash equivalents Cash Equivalents [Member] Other Effective Income Tax Rate Reconciliation, Other Adjustments, Percent Subsequent Event Subsequent Event [Member] Letters of Credit Letters of Credit Outstanding, Amount Defined benefit pension plans Defined Benefit Pension Plans [Abstract] Defined Benefit Pension Plans [Abstract] Common stock - shares authorized (in shares) Common Stock, Shares Authorized Property, plant and equipment, gross Property, Plant and Equipment, Gross Federal Deferred Federal Income Tax Expense (Benefit) Equity Securities - Fourth Fund Equity Securities - Fourth Fund [Member] Equity Securities - Fourth Fund [Member] Summary of Bad Debt Expense Impaired Financing Receivables [Table Text Block] Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Table] Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Table] FERC 2021 TFR Proceeding FERC 2021 TFR Proceeding [Member] FERC 2021 TFR Proceeding Fair Value Estimate of Fair Value Measurement [Member] Income Statement [Abstract] Income Statement [Abstract] AOCI AOCI Attributable to Parent [Member] Alternative investments fund Alternative investments fund Alternative Investment Fund [Member] Alternative Investment Fund [Member] Total long-term obligations under operating leases Operating Lease, Liability, Noncurrent Prepaid expenses and other current assets Increase (Decrease) in Prepaid Expense and Other Assets Regulatory Asset, Amortization Period Regulatory Asset, Amortization Period Change in unrecognized pension expense, net of tax Change in unrecognized pension expense, net of tax Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax Variable Interest Entities Variable Interest Entity, Primary Beneficiary [Member] Interest of VIEs Interest Paid, Including Capitalized Interest, Operating and Investing Activities Debt instrument, debt default, threshold Debt Instrument, Debt Default, Threshold Debt Instrument, Debt Default, Threshold 2021 MPSC Winter Weather 2021 MPSC Winter Weather [Member] 2021 MPSC Winter Weather AAO applied for in June requesting recovery and refund of extraordinary costs and revenues. Residential Electric Utility Customer Class Residential [Member] Residential customer class from which revenues are generated by the regulated sale of electricity [Member] CURRENT ASSETS: Assets, Current [Abstract] Non-service cost component of net benefit cost Non Service Cost Component Of Net Benefit Cost Non Service Cost Component Of Net Benefit Cost Stock to be Sold and Issued Under Securities Purchase Agreement, Shares StockToBeSoldAndIssuedUnderSecuritiesPurchaseAgreement,Shares Equity impact of the number of shares to be issued and sold under the securities purchase agreement. Jointly Owned Electricity Generation Plant Iatan No 1 And 2 Jointly Owned Electricity Generation Plant Iatan No 1 And 2 [Member] Jointly Owned Electricity Generation Plant Iatan No 1 And 2 [Member] Stock repurchased and retired during period under repurchase plan, value Stock Repurchased And Retired During Period Under Repurchase Plan Value Equity impact of the value of stock that has been repurchased and retired during the period under the repurchase plan. The excess of the purchase price over par value can be charged against retained earnings (once the excess is fully allocated to additional paid in capital). AOCI - Net gains (losses) on cash flow hedges AOCI Including Portion Attributable to Noncontrolling Interest [Member] Public Utilities, Requested Refund Increase (Decrease), Amount Public Utilities, Requested Refund Increase (Decrease), Amount Public Utilities, Requested Refund Increase (Decrease), Amount Defined benefit plan basis point change in discount rate DefinedBenefitPlanChangeInDiscountRate DefinedBenefitPlanChangeInDiscountRate Schedule of Defined Benefit Plan, Assumptions Defined Benefit Plan, Assumptions [Table Text Block] Consolidated Entities [Axis] Consolidated Entities [Axis] COMPREHENSIVE INCOME COMPREHENSIVE INCOME Comprehensive Income (Loss), Net of Tax, Attributable to Parent Schedule of Effective Income Tax Rate Reconciliation Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] Proceeds from settlement of interest rate swap Proceeds from Derivative Instrument, Investing Activities Counterparty Name [Domain] Counterparty Name [Domain] Additions to property, plant and equipment Payments to Acquire Property, Plant, and Equipment City Area Code City Area Code Legal Entity [Axis] Legal Entity [Axis] Document Period End Date Document Period End Date LONG-TERM DEBT Long-term Debt [Text Block] Due from Related Parties, Current Due from Related Parties, Current GOODWILL Goodwill and Intangible Assets Disclosure [Text Block] Effect of: Effect Of [Abstract] Effect Of [Abstract] Unbilled Unbilled Revenues [Member] Equity in earnings of equity method investees, net of income taxes Equity in earnings of equity method investees, net of income taxes Income (Loss) from Equity Method Investments Stock repurchase program, authorized amount Stock Repurchase Program, Authorized Amount Warrant to be Issued Under Securities Purchase Agreement for Potential Shares, Maximum WarrantToBeIssuedUnderSecuritiesPurchaseAgreementforPotentialShares,Maximum Maximum number of potential shares granted based on warrant. NET INCOME Net income NET INCOME (LOSS) Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Related party receivables Accounts Receivable, Related Parties, Current Disaggregation of Revenue Disaggregation of Revenue [Table Text Block] INCOME BEFORE INCOME TAXES Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Industrial steam and other Electric Utility Customer Class Industrial Steam [Member] Industrial steam customer class from which revenues are generated by the regulated sale of industrial steam to GMO's steam customers [Member] Other Evergy Other Evergy [Member] Other Evergy [Member] Operating Loss Carryforwards [Table] Operating Loss Carryforwards [Table] Reclassification out of Accumulated Other Comprehensive Income [Domain] Reclassification out of Accumulated Other Comprehensive Income [Domain] Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] AEP Transmission Holding Company, LLC AEP Transmission Holding Company, LLC [Member] AEP Transmission Holding Company, LLC Schedule of Fuel Inventory and Supplies Schedule of Inventory, Current [Table Text Block] Public Utilities Requested Increase of Recovery Public Utilities, Requested Recovery Increase (Decrease), Amount Public Utilities Requested Increase of Recovery Nuclear decommissioning trust - debt securities Decommissioning Trust Assets - Debt [Member] Decommissioning Trust Assets - Debt [Member] Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] Revenues Probable Of Refund RevenuesProbableOfRefund [Member] Discloses the estimated amount of regulatory liability arising from revenues related to Sibley Station that are deemed probable of refund. Repurchase of common stock under repurchase plan Stock Repurchased During Period, Value Non-cash compensation Share-based Payment Arrangement, Noncash Expense Short-term debt, net Proceeds from (Repayments of) Short-term Debt SHORT-TERM BORROWINGS AND SHORT-TERM BANK LINES OF CREDIT Short-term Debt [Text Block] Summary of Related Tax Benefit Amounts Summary of Tax Credit Carryforwards [Table Text Block] Entity [Domain] Entity [Domain] Other financing activities Proceeds from (Payments for) Other Financing Activities Issuance of restricted common stock (in shares) Stock Issued During Period, Shares, Restricted Stock Award, Gross Cover [Abstract] Cover [Abstract] Less:  comprehensive income attributable to noncontrolling interest Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest Regulatory Asset [Domain] Regulatory Asset [Domain] Stock repurchased and retired during period (in shares) Stock Repurchased and Retired During Period, Shares Operating Expenses and Capital Costs Billed Operating Expenses And Capital Costs Billed [Member] Operating Expenses and Capital Costs Billed [Member] Issuance of stock compensation and reinvested dividends, net of tax withholding (in shares) Stock Issued During Period, Shares, Dividend Reinvestment Plan And Share-Based Compensation Net Stock Issued During Period, Shares, Dividend Reinvestment Plan And Share-Based Compensation Net Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Debt securities Debt Securities [Member] Service cost Defined Benefit Plan, Service Cost Kansas property tax surcharge Kansas Property Tax Surcharge [Member] Discloses the amount of regulatory asset arising from the Kansas property tax surcharge not included in rate base and amortized over various periods. Net money pool lending Proceeds from Collection of Advance to Affiliate Asset retirement obligations Asset Retirement Obligations, Noncurrent Borrowing From Mid June Through Expiration Borrowing From Mid June Through Mid November [Member] Borrowing From Mid June Through Mid November [Member] Accrued taxes Increase (Decrease) in Accrued Taxes Payable Amortization of deferred refueling outage Amortization Of Deferred Refueling Outage Costs Amortization Of Deferred Refueling Outage Costs Retained earnings restrictions Equity Restrictions Total Operating Expenses Costs and Expenses Equity Components [Axis] Equity Components [Axis] Derivative hedging activity, net of tax Derivative hedging activity, net of tax Derivative hedging activity, net of tax Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax Remaining Amounts of Regulatory Assets for which No Return on Investment During Recovery Period is Provided Remaining Amounts of Regulatory Assets for which No Return on Investment During Recovery Period is Provided Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Receivables [Abstract] Receivables [Abstract] Fuel recovery mechanisms Deferred Fuel Costs [Member] Consolidated Entities [Domain] Consolidated Entities [Domain] Lease liability recorded in other current liabilities Operating Lease, Liability, Current Other retail Electric Utility Customer Class Other Retail [Member] Other retail customer class from which revenues are generated by the regulated sale of electricity [Member] Supplemental Cash Flow Information Schedule of Cash Flow, Supplemental Disclosures [Table Text Block] Issuance of restricted common stock AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationRestrictedStockUnitsIssuance Adjustments To Additional Paid In Capital Share Based Compensation Restricted Stock Units Issuance Schedule of Short-term Debt [Table] Schedule of Short-term Debt [Table] Right-of-use assets obtained in exchange for new finance lease liabilities Right-of-Use Asset Obtained in Exchange for Finance Lease Liability Less: Net income attributable to noncontrolling interests Net Income (Loss) Attributable to Noncontrolling Interest Shares Delivered (in shares) Settlement Of Accelerated Share Repurchase Agreement, Shares Settlement Of Accelerated Share Repurchase Agreement, Shares Class of Financing Receivable [Domain] Class of Financing Receivable [Domain] Recognized net actuarial (gain) loss Defined Benefit Plan, Amortization of Gain (Loss) Kansas Corporation Commission Kansas Corporation Commission [Member] Information related to the State Corporation Commission of the State of Kansas. La Cygne Station La Cygne Station [Member] La Cygne Station [Member] Schedule of Amounts Recognized in Balance Sheet Schedule of Amounts Recognized in Balance Sheet [Table Text Block] Entity Interactive Data Current Entity Interactive Data Current Net periodic benefit costs (income) Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Schedule of Allocation of Plan Assets Schedule of Allocation of Plan Assets [Table Text Block] FAIR VALUE MEASUREMENTS Fair Value Disclosures [Text Block] CASH FLOWS FROM (USED IN) OPERATING ACTIVITIES: Net Cash Provided by (Used in) Operating Activities [Abstract] Regulatory assets Regulatory Assets, Noncurrent SHAREHOLDERS' EQUITY Stockholders' Equity Note Disclosure [Text Block] Core bond fund Core Bond Fund [Member] Core Bond Fund [Member] Length of settlement Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Liquidating Investment, Remaining Period Decrease in net deferred income tax liabilities due to tax reform Increase Decrease In Net Deferred Income Tax Liabilities Due to Tax Reform Increase/Decrease In Net Deferred Income Tax Liabilities Due to Tax Reform Accounts, Notes, Loans and Financing Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] Billed Billed Revenues [Member] Customer [Domain] Customer [Domain] Actuarial (gain) loss Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Including Portion Attributable to Noncontrolling Interest [Member] Entity Registrant Name Entity Registrant Name Subsequent Event Type [Domain] Subsequent Event Type [Domain] Class of Warrant or Right [Domain] Class of Warrant or Right [Domain] Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Assets Assets, Fair Value Disclosure [Abstract] Allowance for equity funds used during construction Increase (Decrease) in Allowance for Equity Funds Used During Construction Total Other Assets Regulated Entity, Other Assets, Noncurrent Non-qualified benefit obligations UnfundedAccumulatedBenefitObligationForNonQualifiedPlans The unfunded accumulated benefit obligation related to non-qualified benefit plans. Transmission line length Transmission Line Length Transmission Line Length Regulatory liabilities Regulatory Liability, Current Number of segments Number of Reportable Segments Components of Income Tax Expense (Benefit), Continuing Operations [Abstract] Components of Income Tax Expense (Benefit), Continuing Operations [Abstract] Retirement Plan Type [Domain] Retirement Plan Type [Domain] Regulatory assets Regulatory Assets High-yield bond fund High-Yield Bond Fund [Member] High-Yield Bond Fund [Member] Amortization of corporate-owned life insurance Amortization Of Corporate Owned Life Insurance Amortization Of Corporate Owned Life Insurance Net gain arising during period Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, before Tax Collateralized short-term borrowings, net Collateralized short-term debt, net Proceeds From (Payments For) Issuance Of Collateralized Debt Net Proceeds From (Payments For) Issuance Of Collateralized Debt Net Equity securities Equity Securities [Member] Stock Canceled During Period, Value Stock Canceled During Period, Value Stock Canceled During Period, Value Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Receivables, net of allowance for credit losses of $20.0 and $19.3, respectively Receivables, net of allowance for credit losses of $7.6 and $7.5, respectively Receivables, net of allowance for credit losses of $8.7 and $8.1, respectively Total Accounts Receivable, after Allowance for Credit Loss, Current RATE MATTERS AND REGULATION Public Utilities Disclosure [Text Block] Ownership interest Noncontrolling Interest, Ownership Percentage by Parent Depreciation and amortization Depreciation, Depletion and Amortization, Nonproduction Income from corporate-owned life insurance Income from corporate-owned life insurance Income From Corporate Owned Life Insurance Income From Corporate Owned Life Insurance Restricted Stock Units (RSUs), Service Requirements Restricted Stock Units (RSUs), Service Requirements [Member] Restricted Stock Units (RSUs), Service Requirements [Member] Summary Of Accounting Policies [Table] Summary Of Accounting Policies [Table] Summary Of Accounting Policies [Table] Repayment of borrowings against cash surrender value of corporate-owned life insurance Repayments Of Borrowings Against Corporate Owned Life Insurance Repayments Of Borrowings Against Corporate Owned Life Insurance State Tax Reform [Line Items] Operating Loss Carryforwards [Line Items] Entity Address, Postal Zip Code Entity Address, Postal Zip Code Amortization Investment Tax Credit Amortization The amount deducted from an entities' taxes, reflecting a percentage of an amount invested in certain assets spread over the useful life of those assets; the part related to the amortization of investment tax credits. Goodwill Goodwill Goodwill August 2018 ASR Agreement August 2018 ASR Agreement [Member] August 2018 ASR Agreement [Member] Document Transition Report Document Transition Report Deferred income taxes Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract] Warrant Warrant [Member] Derivative hedging activity Derivative Hedging Activity [Abstract] Derivative Hedging Activity [Abstract] Payment for settlement of interest rate swap accounted for as a cash flow hedge Payment for settlement of interest rate swap accounted for as a cash flow hedge Payments for Hedge, Financing Activities Dividends declared on common stock (in dollars per share) Common Stock, Dividends, Per Share, Declared Debt issued Debt Instrument, Face Amount Level 2 Fair Value, Inputs, Level 2 [Member] Other assets Other Assets, Current Document Quarterly Report Document Quarterly Report Current income taxes Current Income Tax Expense (Benefit), Continuing Operations [Abstract] Asset Class [Domain] Asset Class [Domain] Total Assets Assets, Fair Value Disclosure Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Non-cash investing transactions: Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] NAV, number of funds Fair Value, Investments, Entities That Calculate Net Asset Value, Number Of Funds Fair Value, Investments, Entities that Calculate Net Asset Value, Number Of Funds Jeffrey Energy Center Jeffrey Energy Center [Member] Jeffrey Energy Center [Member] Senior Notes Due 2033 EMW Senior Notes Series B due 2033 EMW [Member] Senior Notes Series B due 2033 EMW. Entities [Table] Entities [Table] Credit Facility [Domain] Credit Facility [Domain] Diluted (in shares) Diluted average number of common shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Diluted Basic earnings per common share (in dollars per share) Earnings Per Share, Basic Regulatory Proceedings [Table] Public Utilities General Disclosures [Table] OTHER INCOME (EXPENSE): Other Income and Expenses [Abstract] Entity File Number Entity File Number Senior Notes Series B due 2033 EMW SeniorNotesSeriesB3.01PercentDue2033EMW [Member] Senior Notes Series B 3.01 percent due 2033 EMW Debt Disclosure [Abstract] Debt Disclosure [Abstract] Pension and post-retirement liability Liability, Defined Benefit Plan, Noncurrent Fuel inventory and supplies Fuel inventory and supplies Energy Related Inventory Recoveries of prior write-offs Accounts Receivable, Allowance for Credit Loss, Recovery Inventory, Current [Table] Inventory, Current [Table] Geographic Distribution [Domain] Geographic Distribution [Domain] Jointly Owned Utility Plant [Domain] Jointly Owned Utility Plant [Domain] Purchase of securities - trusts Payments to Acquire Investments to be Held in Decommissioning Trust Fund Unsecured Debt Unsecured Debt [Member] Net Cash Provided by (Used in) Financing Activities, Total Cash Flows from Financing Activities Net Cash Provided by (Used in) Financing Activities Retirements of long-term debt Retirements of long-term debt Repayments of Long-term Debt Maximum amount of outstanding principal under receivables agreement Maximum Amount Of Outstanding Principal Under Receivables Agreement Maximum amount of outstanding principal under receivables agreement Annual estimated loss contingency portion not accrued (up to) Annual Estimated Loss Contingency Portion Not Accrued Annual estimated amount of revenues collected related to Sibley Station that Evergy does not believe will be required to be refunded. Counterparty Name [Axis] Counterparty Name [Axis] Common stock - 600,000,000 shares authorized, without par value 229,296,214 and 226,836,670 shares issued, stated value Common stock Common Stock, Value, Issued Goodwill and Intangible Assets Disclosure [Abstract] Goodwill and Intangible Assets Disclosure [Abstract] Document Fiscal Year Focus Document Fiscal Year Focus Document Annual Report Document Annual Report Flow through depreciation for plant-related differences EffectiveIncomeTaxRateReconciliationEffectOfRegulatoryTreatmentBookTaxDifferences Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to the effect of regulatory treatment of book and tax differences. Commercial Paper Commercial Paper [Member] Current maturities of long-term debt Long-term Debt, Current Maturities Schedule of Receivables Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Entity Current Reporting Status Entity Current Reporting Status Funded by trusts containing assets SegregatedAssetsForNonQualifiedBenefitPlans SegregatedAssetsForNonQualifiedBenefitPlans CostsProbableofRefund CostsProbableofRefund [Member] Discloses the estimated amount of regulatory assets arising from costs related to the February 2021 winter weather event that are probable of refund. Retirement Benefits [Abstract] Retirement Benefits [Abstract] Related Party Transaction [Axis] Related Party Transaction [Axis] Receivable [Domain] Receivable [Domain] Wolf Creek Jointly Owned Nuclear Power Plant [Member] Changes In Uncertain Tax Positions, Net EffectiveIncomeTaxRateReconciliationChangesInUncertainTaxPositionsNet Effective Income Tax Rate Reconciliation, Changes In Uncertain Tax Positions, Net Total rabbi trust Rabbi Trust, Fair Value Disclosure Rabbi Trust, Fair Value Disclosure Number of customers served Number Of Customers Served Number Of Customers Served Owned generating capacity and renewable purchased power Owned Generating Capacity And Renewable Purchased Power Owned Generating Capacity and Renewable Purchased Power Earnings Per Share Earnings Per Share, Policy [Policy Text Block] COMPREHENSIVE INCOME Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Borrowings From Mid October Through Mid June Borrowings From Mid October Through Mid June [Member] Borrowings From Mid October Through Mid June [Member] Noncontrolling Interests Stockholders' Equity Attributable to Noncontrolling Interest Maximum Amount Of First Mortgage Bonds Authorized Maximum Amount Of First Mortgage Bonds Authorized The maximum amount of First Mortgage Bonds authorized to be issued under the mortgage and deed of trust. Wholesale Electric Utility Customer Class Wholesale [Member] Wholesale customer class from which revenues are generated by the sale of wholesale power and capacity when the power is not required for customers within service territory [Member] CASH FLOWS FROM (USED IN) INVESTING ACTIVITIES: Net Cash Provided by (Used in) Investing Activities [Abstract] Common stock - shares issued (in shares) Common Stock, Shares, Issued Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Number of active wholly owned subsidiaries Number Of Wholly Owned Subsidiaries Number Of Wholly Owned Subsidiaries NAV, number of extensions Fair Value, Investments, Entities That Calculate Net Asset Value, Number Of Extensions Fair Value, Investments, Entities that Calculate Net Asset Value, Number Of Extensions Other Other Revenue Revenue other than from contracts with customers. Public Utilities, Regulatory Proceeding [Domain] Public Utilities, Regulatory Proceeding [Domain] Operating and maintenance Utilities Operating Expense, Maintenance and Operations Schedule of Defined Benefit Plans Disclosures [Table] Schedule of Defined Benefit Plans Disclosures [Table] Long-term debt, net Long-term Debt, Excluding Current Maturities Non-controlling interest Effective Income Tax Rate Reconciliation, Noncontrolling Interest Income (Loss), Percent Regulatory liabilities Regulatory Liabilities Fuel inventory Energy Related Inventory, Coal Schedule of Fair Value Recurring Gain (Loss) Included in Earnings Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Table Text Block] Share Repurchase Program [Axis] Share Repurchase Program [Axis] Basis of Presentation Basis of Presentation and Significant Accounting Policies [Text Block] Accounts receivable Increase (Decrease) in Accounts Receivable Debt Instrument [Line Items] Debt Instrument [Line Items] Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Total Evergy, Inc. Shareholders' Equity Stockholders' Equity Attributable to Parent Stock issuance costs Payments of Stock Issuance Costs Restricted Stock Units With Service Requirements Restricted Stock Units With Service Requirements [Member] Restricted Stock Units With Service Requirements Related Party Transaction, Due from (to) Related Party, Current [Abstract] Related Party Transaction, Due from (to) Related Party, Current [Abstract] Retirements of long-term debt of variable interest entities Retirements of Long Term Debt Of VIEs Retirements of Long Term Debt Of VIEs TOTAL LIABILITIES AND EQUITY Liabilities and Equity AFUDC equity EffectiveIncomeTaxRateReconciliationAFUDCEquity Effective Income Tax Rate Reconciliation, AFUDC Equity Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax TAXES Income Tax Disclosure [Text Block] Total Long-Term Liabilities Liabilities, Noncurrent Entity Address, City or Town Entity Address, City or Town COLI policies Effective Income Tax Rate Reconciliation, Nondeductible Expense, Life Insurance, Percent Portion at Fair Value Measurement [Member] Portion at Fair Value Measurement [Member] Accrued compensation and benefits Employee-related Liabilities, Current Fair Value Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Evergy Inc Money Pool Evergy Inc Money Pool [Member] Transactions related to the Evergy Inc Money Pool, an internal financing arrangement between Evergy Inc, Evergy Metro and Evergy Missouri West. Equity funds Other Equity Fund [Member] Other Equity Fund Property, plant and equipment additions Non Cash Property Plant And Equipment Additions, Gross Non-cash property, plant and equipment additions, Gross Antidilutive securities excluded from computation of earnings per share, amount Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Total Current Income Tax Expense (Benefit) Line of Credit Facility [Line Items] Line of Credit Facility [Line Items] Refund percent on earnings over approved return on equity Public Utilities, Refund Percent On Earnings Over Approved Return On Equity Public Utilities, Refund Percent On Earnings Over Approved Return On Equity Other Other Noncash Income (Expense) Income tax benefit Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, Tax Officer compensation limitation EffectiveIncomeTaxRateReconciliationOfficerCompensationLimitation Officer compensation limitation Equity Component [Domain] Equity Component [Domain] Weighted Average Interest Rate on Short-Term Borrowings Line of Credit Facility, Interest Rate at Period End Cash dividends paid Payments of Dividends Schedule of Expected Benefit Payments Schedule of Expected Benefit Payments [Table Text Block] Schedule of Fair Value Investments, Entities that Calculate NAV Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Table Text Block] PROPERTY, PLANT AND EQUIPMENT, NET Property, plant and equipment, net Property, Plant and Equipment, Net Construction work in progress Construction in Progress [Member] Entity Tax Identification Number Entity Tax Identification Number Other Other Trust Assets [Member] Other assets within the trust fund. Warrants and Rights Outstanding, Term Warrants and Rights Outstanding, Term Investment in corporate-owned life insurance Investment in corporate-owned life insurance Payment to Acquire Life Insurance Policy, Investing Activities Net income attributable to Evergy, Inc. Net Income (Loss) Attributable to Parent Repayment of term loan facility Repayment of term loan facility The cash outflow for a term loan borrowing having a initial term of repayment within one year. Receivables Billing Status [Domain] Receivables Billing Status [Domain] Changes in working capital items: Increase (Decrease) in Operating Capital [Abstract] Other Other Liabilities, Current Distributions to shareholders of noncontrolling interests Payments to Noncontrolling Interests Transmission line electrical potential Transmission Line Electrical Potential Transmission Line Electrical Potential Investment, Name [Domain] Investment, Name [Domain] Total other comprehensive income (loss) Other Comprehensive Income (Loss), Net of Tax Regulatory Asset [Axis] Regulatory Asset [Axis] ORGANIZATION AND BASIS OF PRESENTATION Organization, Consolidation and Presentation of Financial Statements Disclosure and Significant Accounting Policies [Text Block] Related party payables Accounts Payable, Related Parties, Current Taxes other than income tax Taxes, Miscellaneous Consolidation of noncontrolling interests Noncontrolling Interest, Increase From Consolidation Net Noncontrolling Interest, Increase From Consolidation Net Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] Total Current Assets Assets, Current Current Fiscal Year End Date Current Fiscal Year End Date Schedule of Deferred Income Tax Assets and Liabilities Schedule of Deferred Tax Assets and Liabilities [Table Text Block] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] NAV Fair Value Measured at Net Asset Value Per Share [Member] State income taxes Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent Other income Other Nonoperating Income Combination debt/equity/other fund Debt Equity Other Fund [Member] Debt Equity Other Fund [Member] Evergy, Inc. Shareholders' Equity: Evergy, Inc. Shareholders' Equity: Stockholders' Equity Attributable to Parent [Abstract] Net periodic benefit costs before regulatory adjustment and intercompany allocations Net Period Benefit Costs Before Regulatory Adjustment And Intercompany Allocations The total amount of net periodic benefit cost for defined benefit plans for the period before regulatory adjustment and intercompany allocations. Periodic benefit costs include the following components: service cost, interest cost, expected return on plan assets, gain (loss), prior service cost or credit, transition asset or obligation, and gain (loss) due to settlements or curtailments. Document Fiscal Period Focus Document Fiscal Period Focus U.S. Agency US Government Corporations and Agencies Securities [Member] Issuance of restricted common stock Stock Issued During Period, Value, Restricted Stock Award, Gross Amortization of net losses included in net periodic benefit costs, net of tax Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, after Tax Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items] Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items] Evergy, Inc. Evergy Evergy [Member] Evergy [Member] Contributions by employer Defined Benefit Plan, Plan Assets, Contributions by Employer Stock to be Sold and Issued Under Securities Purchase Agreement, Value StockToBeSoldandIssuedUnderSecuritiesPurchaseAgreement,Value Equity impact of the value of stock that was sold and issued under the securities purchase agreement. Cash paid for (received from): Supplemental Cash Flow Information [Abstract] Effective Income Tax Rate Reconciliation, Percent [Abstract] Effective Income Tax Rate Reconciliation, Percent [Abstract] Entity Filer Category Entity Filer Category Common Stock Common Stock Common Stock [Member] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Property, Plant and Equipment, Type [Domain] Long-Lived Tangible Asset [Domain] AdditionalPrincipalFirstMortgageBondsAvailableToBeIssued AdditionalPrincipalFirstMortgageBondsAvailableToBeIssued Principal amount of additional first mortgage bonds available to be issued under th most restrictive mortgage provisions. Notes payable and commercial paper Short-term Bank Loans and Notes Payable Summary of Property, Plant and Equipment Property, Plant and Equipment [Table Text Block] Income Tax Receivable Income Tax Receivable [Member] Income Tax Receivable [Member] Secured Debt Secured Debt [Member] Available Borrowings Line of Credit Facility, Remaining Borrowing Capacity Issuance of stock, net of issuance costs (in shares) Stock Issued During Period, Shares, New Issues RECEIVABLES Loans Notes Trade And Other Receivables Disclosure And Transfers And Servicing Of Financial Asset [Text Block] Includes disclosure of claims held for amounts due a company. Examples include trade accounts receivables, notes receivables, loans receivables. Also provides the disclosures pertaining to a transferor's continuing involvement in financial assets that it has transferred in a securitization or asset-backed financing arrangements. Schedule of Health Care Cost Trend Rates Schedule of Health Care Cost Trend Rates [Table Text Block] Interest rate Interest rate Debt Instrument, Interest Rate, Stated Percentage Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table] Credit loss expense Accounts Receivable, Credit Loss Expense (Reversal) Commercial Electric Utility Customer Class Commercial [Member] Commercial customer class from which revenues are generated by the regulated sale of electricity [Member] Federal Energy Regulatory Commission Federal Energy Regulatory Commission [Member] Federal Energy Regulatory Commission [Member] Accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment Schedule of Related Party Receivables and Payables Schedule of Related Party Transactions [Table Text Block] Regulatory Liability, Amortization Period Regulatory Liability, Amortization Period Related Party Transactions [Abstract] Related Party Transactions [Abstract] Supplies Energy Related Inventory, Supplies Energy Related Inventory, Supplies NET CHANGE IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect Total Other Income (Expense), Net Total Other Expense, Net Nonoperating Income (Expense) Borrowings against cash surrender value of corporate-owned life insurance Proceeds From Borrowings Against Corporate Owned Life Insurance Proceeds From Borrowings Against Corporate Owned Life Insurance Real estate securities fund Real estate securities fund Real Estate Funds [Member] Proceeds from term loan facility Proceeds from term loan facility The cash inflow from a term loan having initial term of repayment within one year. Investment Tax Credits InvestmentTaxCredits [Abstract] Investment Tax Credits Issuance of stock for compensation and reinvested dividends Stock Issued Basic (in shares) Weighted average equivalent common shares outstanding - basic (in shares) Weighted Average Number of Shares Outstanding, Basic OPERATING EXPENSES: Costs and Expenses [Abstract] Ownership [Axis] Ownership [Axis] SPP network transmission costs SPPNetworkTransmissionCosts Cost incurred for SPP transmission costs Cash and cash equivalents Cash and Cash Equivalents [Member] Unamortized investment tax credits Accumulated Deferred Investment Tax Credit Amortization of federal investment tax credits Effective Income Tax Rate Reconciliation, Tax Credit, Investment, Percent State Deferred State and Local Income Tax Expense (Benefit) Ownership [Domain] Ownership [Domain] Book Value Reported Value Measurement [Member] FERC 2019 TFR Proceeding FERC 2019 TFR Proceeding [Member] FERC 2019 TFR Proceeding Net money pool lending Payments for Advance to Affiliate Entity Well-known Seasoned Issuer Entity Well-known Seasoned Issuer REVENUE Revenue from Contract with Customer [Text Block] Interest, net of amount capitalized Interest Paid, Excluding Capitalized Interest, Operating Activities Dividends payable Dividends Payable Ownership percentage Equity Method Investment, Ownership Percentage Other current liabilities Increase (Decrease) in Other Current Liabilities Borrowing From Mid June Through Mid October Borrowing From Mid June Through Mid October [Member] Borrowing From Mid June Through Mid October Total Equity Beginning balance Ending balance Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Right-of-use assets obtained in exchange for new operating lease liabilities Right-of-Use Asset Obtained in Exchange for Operating Lease Liability Long-term debt Long-term Debt, Fair Value OPERATING REVENUES Revenues Revenues Class of Stock [Axis] Class of Stock [Axis] Fuel Inventory and Supplies Inventory, Policy [Policy Text Block] Income tax expense Income tax expense (benefit) Income tax expense Income Tax Expense (Benefit) Income taxes, net of refunds Income Taxes Paid, Net Stock Canceled During Period Shares Net Stock Canceled During Period Shares Net Stock Canceled During Period Shares Net Beginning of period End of period Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Schedule of Maturities of Long-Term Debt Schedule of Maturities of Long-term Debt [Table Text Block] Income tax benefit Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, Tax Diluted earnings per common share (in dollars per share) Earnings Per Share, Diluted Variable Interest Entity [Line Items] Variable Interest Entity [Line Items] Local Phone Number Local Phone Number Schedule of Short-term Debt Schedule of Short-term Debt [Table Text Block] Industrial Electric Utility Customer Class Industrial [Member] Industrial customer class from which revenues are generated by the regulated sale of electricity [Member] Deferred Customer Programs [Member] Deferred Customer Programs [Member] Discloses the amount of regulatory asset arising from deferred customer program. Schedule of Debt Schedule of Debt [Table Text Block] November 2018 ASR Agreement November 2018 ASR Agreement [Member] November 2018 ASR Agreement [Member] Prior service cost Accumulated Defined Benefit Plans Adjustment, Net Prior Service Including Portion Attributable to Noncontrolling Interest [Member] Long-term debt gross Long-term debt gross Long-term Debt, Gross Nuclear decommissioning trust fund Decommissioning Fund Investments Total self-insured health plan trust Self Insured Health Plan Trust Fair Value Disclosure The fair value of investments held in a trust for KCP&L's self-insurance health plan. Entity Address, Address Line One Entity Address, Address Line One Related Party Transaction [Domain] Related Party Transaction [Domain] Changes in other assets Increase (Decrease) in Other Operating Assets Entity Emerging Growth Company Entity Emerging Growth Company Total Deferred Income Tax Expense (Benefit) Rabbi trust: Rabbi trusts - equity securities Rabbi Trusts [Member] Rabbi Trusts [Member] Line of credit, maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Consolidated Entity Excluding Variable Interest Entities (VIE) Consolidated Entity Excluding Variable Interest Entities (VIE) [Member] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items] Class of Financing Receivable [Axis] Class of Financing Receivable [Axis] Maximum Maximum [Member] Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Non-controlling interests Noncontrolling Interest [Member] Investment earnings Investment earnings Gain (Loss) on Investments Dividends declared on common stock Dividends, Common Stock, Cash Approved return on equity, percentage Public Utilities, Approved Return on Equity, Percentage Analog meter unrecovered investment Analog Meter Unvrecovered Investment [Member] Discloses the deferral of unrecovered investment of retired analog meters. Unfunded Commitments Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments Retained earnings Retained Earnings [Member] Measurement Basis [Axis] Measurement Basis [Axis] Effective income tax rate Effective Income Tax Rate Reconciliation, Percent Unrealized gain (losses) Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss) Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Schedule of Net Benefit Costs Schedule of Net Benefit Costs [Table Text Block] Cash Flows used in Investing Activities Net Cash Provided by (Used in) Investing Activities Increase of Energy Marketing Margins Increase of Energy Marketing Margins Increase of energy marketing/trading margins Evergy Metro Evergy Metro Evergy Metro Evergy Metro Inc [Member] Evergy Metro Inc [Member] Summary Of Accounting Policies [Line Items] Summary Of Accounting Policies [Line Items] [Line Items] for Summary Of Accounting Policies [Table] Other expense Other expense Other Nonoperating Expense LONG-TERM LIABILITIES: Liabilities, Noncurrent [Abstract] FERC 2020 TFR Proceeding FERC 2020 TFR Proceeding [Member] FERC 2020 TFR Proceeding [Member] Corporate bonds Corporate Debt Securities [Member] Post-Retirement Benefits Other Postretirement Benefits Plan [Member] Trading Symbol Trading Symbol Other receivables, contracts with customers Other Receivables, Contracts With Customers The amount of other receivables resulting from contracts with customers. AVERAGE COMMON SHARES OUTSTANDING Common Shares Outstanding Weighted Average Number of Shares Outstanding Reconciliation [Abstract] Jointly owned utility plant, proportionate ownership share Jointly Owned Utility Plant, Proportionate Ownership Share Regulatory Liability [Axis] Regulatory Liability [Axis] Jointly Owned Utility Plant [Axis] Jointly Owned Utility Plant [Axis] Evergy Kansas Central Evergy Kansas Central Inc [Member] Utility operating in Kansas. 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