Nuclear decommissioning trust fund Decommissioning Fund Investments Cash paid for (received from): Supplemental Cash Flow Information [Abstract] Customer [Domain] Customer [Domain] Federal statutory income tax rate Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent Evergy Kansas South Inc Evergy Kansas South Inc [Member] Evergy Kansas South Inc [Member] Earnings Per Share Earnings Per Share, Policy [Policy Text Block] State Current State and Local Tax Expense (Benefit) Fair Value Hierarchy and NAV [Domain] Fair Value Hierarchy and NAV [Domain] Senior Notes Due 2025 EMW Senior Notes Series A due 2025 EMW [Member] Senior Notes Series A due 2025 EMW Net income attributable to Evergy, Inc. Net Income (Loss) Attributable to Parent Consolidated Entities [Axis] Consolidated Entities [Axis] Nuclear decommissioning trust - equity securities Decommissioning Trust Assets - Equity [Member] Decommissioning Trust Assets - Equity [Member] Interest cost Defined Benefit Plan, Interest Cost Accrued compensation and benefits Employee-related Liabilities, Current Accounts, Notes, Loans and Financing Receivable by Receivable Type [Axis] Receivable Type [Axis] Statistical Measurement [Domain] Statistical Measurement [Domain] Prairie Wind Transmission, LLC Prairie Wind Transmission, LLC [Member] Prairie Wind Transmission, LLC [Member] Schedule of Maturities of Long-Term Debt Schedule of Maturities of Long-term Debt [Table Text Block] Dividends declared on common stock Dividends, Common Stock, Cash Security Exchange Name Security Exchange Name Emerging markets bond fund Emerging Markets Bond Fund [Member] Emerging Markets Bond Fund [Member] Entity Incorporation, State or Country Code Entity Incorporation, State or Country Code Revenue from Contract with Customer [Abstract] Revenue from Contract with Customer [Abstract] Regulatory Agency [Domain] Regulatory Agency [Domain] Summary of Bad Debt Expense Impaired Financing Receivables [Table Text Block] 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] Prior service cost Accumulated Defined Benefit Plans Adjustment, Net Prior Service Including Portion Attributable to Noncontrolling Interest [Member] Income Earnings Per Share Reconciliation [Abstract] Approved return on equity, percentage Public Utilities, Approved Return on Equity, Percentage Early-Stage Energy Solution Company Early-Stage Energy Solution Company [Member] Early-Stage Energy Solution Company Other Other Assets, Noncurrent Investment, Name [Axis] Investment, Name [Axis] Expected return on plan assets Defined Benefit Plan, Expected Return (Loss) on Plan Assets 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 Retirement Benefits [Abstract] Retirement Benefits [Abstract] 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 Entity File Number Entity File Number Increase in Wholesale Revenues Increase in Wholesale Revenues Increase in Wholesale Revenues Schedule of Other Nonoperating Income (Expense) Schedule of Other Nonoperating Income (Expense) [Table Text Block] Other Other Nonoperating Income (Expense), Other Other Nonoperating Income (Expense), Other Stock compensation expense APIC, Share-based Payment Arrangement, Increase for Cost Recognition Class of Financing Receivable [Axis] Class of Financing Receivable [Axis] Electric plant in service Electric Plant In Service [Member] Electric Plant In Service [Member] Senior Notes Series C due 2036 EMW SeniorNotesSeriesCDue2036EMW [Member] Senior Notes Series C Due 2036 EMW Subsequent Event Type [Domain] Subsequent Event Type [Domain] Nuclear decommissioning trust: Decommissioning Trust Assets [Member] Decommissioning Trust Assets [Member] Equity investment loss, net of derivative gain EquityInvestmentGain(Loss)NetOfDerivativeGain(Loss) Equity investment gain (loss), net of derivative gain (loss) Antidilutive securities excluded from computation of earnings per share, amount Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Schedule of Fuel Inventory and Supplies Schedule of Inventory, Current [Table Text Block] Missouri Public Service Commission MissouriPublicServiceCommission [Member] Information related to the Public Service Commission of the State of Missouri. Net gain arising during period, net of tax Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, 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] Net money pool lending Payments for Advance to Affiliate COLI policies Effective Income Tax Rate Reconciliation, Nondeductible Expense, Life Insurance, Percent Jointly owned utility plant, proportionate ownership share Jointly Owned Utility Plant, Proportionate Ownership Share Pension and post-retirement liability Liability, Defined Benefit Plan, Noncurrent 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. Local Phone Number Local Phone Number Credit Facility [Domain] Credit Facility [Domain] ASSETS Assets [Abstract] Related Party Transactions [Abstract] Related Party Transactions [Abstract] Recognized net actuarial (gain) loss Defined Benefit Plan, Amortization of Gain (Loss) Right-of-use assets obtained in exchange for new finance lease liabilities Right-of-Use Asset Obtained in Exchange for Finance Lease Liability Accounts receivable pledged as collateral Transfers Accounted for as Secured Borrowings, Assets, Carrying Amount State and local obligations US States and Political Subdivisions Debt Securities [Member] Plant to be retired, net Plant To Be Retired [Member] Plant To Be Retired [Member] Changes in other liabilities Increase (Decrease) in Other Noncurrent Liabilities Borrowings From Mid-November Through Mid-June Borrowings From Mid November Through Mid June [Member] Borrowings From Mid November Through Mid June [Member] Cash equivalents Cash Equivalents [Member] GOODWILL Goodwill and Intangible Assets Disclosure [Text Block] Class of Financing Receivable [Domain] Class of Financing Receivable [Domain] 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 Retained earnings Retained Earnings [Member] Debt Instrument [Axis] Debt Instrument [Axis] Pension and post-retirement costs Pension and Other Postretirement Plans Costs [Member] Prepaid expenses and other current assets Increase (Decrease) in Prepaid Expense and Other Assets Schedule of Fair Value Recurring Gain (Loss) Included in Earnings Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Table Text Block] Customer accounts receivable Trade Accounts Receivable [Member] LONG-TERM LIABILITIES: Liabilities, Noncurrent [Abstract] Ownership interest Noncontrolling Interest, Ownership Percentage by Parent COMMITMENTS AND CONTINGENCIES Commitments and Contingencies Disclosure [Text Block] Rate-making equity ratio, requested Public Utilities, Requested Equity Capital Structure, Percentage Debt securities Debt Securities [Member] VIE ownership percentage Variable Interest Entity, Qualitative or Quantitative Information, Ownership Percentage Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table] Related Party [Axis] Related Party [Axis] Real estate securities fund Real estate securities fund Real Estate Funds [Member] Prior service cost Defined Benefit Plan, Amortization of Prior Service Cost (Credit) Secured Debt Secured Debt [Member] Inventory, Current [Table] Inventory, Current [Table] Accounts receivable Increase (Decrease) in Accounts Receivable Annual revenue increase (decrease), requested, not including rebasing fuel, purchased power expense and/or property tax expense PublicUtilitiesRequestedRateIncreaseDecreaseAmountNotIncludingRebasingFuelPurchasedPowerExpenseAndPropertyTaxExpense PublicUtilitiesRequestedRateIncreaseDecreaseAmountNotIncludingRebasingFuelPurchasedPowerExpenseAndPropertyTaxExpense Right-of-use assets obtained in exchange for new operating lease liabilities Right-of-Use Asset Obtained in Exchange for Operating Lease Liability 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 Non-cash financing transactions: Other Noncash Investing and Financing Items [Abstract] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] COMPREHENSIVE INCOME Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest 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 Net loss arising during period Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, before Tax Equity investment fair value Equity Securities, FV-NI Available Borrowings Line of Credit Facility, Remaining Borrowing Capacity Basic earnings per common share (in dollars per share) Earnings Per Share, Basic Earnings Per Share, Basic 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 U.S. Treasury US Treasury and Government [Member] Schedule of Fair Value Investments, Entities that Calculate NAV Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Table Text Block] REVENUE Revenue from Contract with Customer [Text Block] 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. Property, plant and equipment, adjustment Property, Plant And Equipment, Adjustment Property, Plant And Equipment, Adjustment Regulatory Agency [Axis] Regulatory Agency [Axis] 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. Length of settlement Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Liquidating Investment, Remaining Period 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 Prepaid expenses Prepaid Expense, Current Disaggregation of Revenue Disaggregation of Revenue [Table Text Block] RSU With Performance Measures Restricted Stock Units With Performance Measures [Member] Restricted Stock Units With Performance Measures [Member] Consolidated Entity Excluding Variable Interest Entities (VIE) Consolidated Entity, Excluding Consolidated VIE [Member] 2018 MPSC OPC MECG Petition 2018MPSCOPCMECGPetition [Member] 2018 MPSC Petition filed by OPC MECG requesting an accounting authority order[Member] Fair Value Measurement [Domain] Fair Value Measurement [Domain] Due from (to) related parties Related Party Transaction, Due from (to) Related Party, Current 2022 Rate case proceedings 2022RateCaseProceedings [Member] 2022 Rate case proceedings Senior Notes Due 2043 EMW Senior Notes Series C due 2043 EMW [Member] Senior Notes Series C due 2043. Commercial Paper Commercial Paper [Member] Short-term debt, net Proceeds from (Repayments of) Short-term Debt Other Other Noncash Income (Expense) Recoveries of prior write-offs Accounts Receivable, Allowance for Credit Loss, Recovery Return on equity, requested Public Utilities, Requested Return on Equity, Percentage Regulatory assets Regulatory Assets, Current Initial Investment On Equity Investment InitialInvestmentOnEquityInvestment Initial Investment On Equity Investment 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. Gain on derivative hedging instruments Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax Regulatory Liability [Axis] Regulatory Liability [Axis] Credit loss expense Accounts Receivable, Credit Loss Expense (Reversal) Long-term debt gross Long-term debt gross Long-term Debt, Gross Assets Assets, Fair Value Disclosure [Abstract] Fixed income funds Fixed Income Funds [Member] Fuel and purchased power FuelAndPurchasedPower Amount of operating expense for fuel and purchased power used by regulated operation Total Assets Assets, Fair Value Disclosure Sale of securities - trusts Proceeds from Decommissioning Trust Fund Assets Level 1 Fair Value, Inputs, Level 1 [Member] CASH FLOWS FROM (USED IN) INVESTING ACTIVITIES: Net Cash Provided by (Used in) Investing Activities [Abstract] Fuel inventory and supplies Increase (Decrease) In Energy Related Inventory Increase (Decrease) In Energy Related Inventory Income Taxes Payable Income Taxes Payable [Member] Income Taxes Payable [Member] Income Tax Disclosure [Abstract] Income Tax Disclosure [Abstract] Entity Small Business Entity Small Business Cash and cash equivalents Cash and Cash Equivalents [Member] Federal tax credits Effective Income Tax Rate Reconciliation, Tax Credit, Other, Percent 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. TOTAL LIABILITIES AND EQUITY Liabilities and Equity Other Effective Income Tax Rate Reconciliation, Other Adjustments, Percent Regulatory Proceedings [Line Items] Public Utilities, General Disclosures [Line Items] 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 OTHER INCOME (EXPENSE): Other Income and Expenses [Abstract] Utility Financing and Securitization Act - KS Utility Financing and Securitization Act - KS [Member] Legislation enacted in 2021 in KS which allows certain utilities, to securitize utility assets in order to recover energy transition costs relating to early retirement of generating assets. 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. LIABILITIES AND EQUITY Liabilities and Equity [Abstract] Deferral InvestmentTaxCreditDeferral Investment Tax Credit Deferral 2018 Rate Case Proceedings 2018 Rate Case Proceedings [Member] 2018 Rate Case Proceedings [Member] Accounts payable Increase (Decrease) in Accounts Payable Cash settlements under share forward agreement Payments for (Proceeds from) Derivative Instrument, Investing Activities 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. Income Tax Contingency [Table] Income Tax Contingency [Table] Short-term Debt, Type [Domain] Short-term Debt, Type [Domain] 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] Ownership percentage Equity Method Investment, Ownership Percentage Entity Interactive Data Current Entity Interactive Data Current Senior Notes Series Due 2022 EMW Senior Notes Series Due 2022 EMW [Member] Senior Notes Series Due 2022 EMW [Member] Regulatory liabilities Regulatory Liabilities Letters of Credit Standby Letters of Credit [Member] Regulatory adjustment Defined Benefit Plan Regulatory Adjustment Net Increase (decrease) in net periodic benefit costs related to regulatory adjustments Net. Minimum Minimum [Member] Settlement and special termination benefits Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement Income taxes receivable Income Taxes Receivable, Current Long-term line of credit Long-term Line of Credit Evergy Transmission Company LLC Evergy Transmission Company LLC [Member] Evergy Transmission Company LLC [Member] INCOME BEFORE INCOME TAXES Income (Loss) from Continuing Operations before Equity Method Investments, Income Taxes, Noncontrolling Interest Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Unearned compensation UnearnedCompensation [Abstract] UnearnedCompensation Entity Address, State or Province Entity Address, State or Province Senior Notes Series A due 2031 EMW SeniorNotesSeriesADue2031EMW [Member] Senior Notes Series A due 2031 EMW CURRENT LIABILITIES: Liabilities, Current [Abstract] Amortization of federal investment tax credits Effective Income Tax Rate Reconciliation, Tax Credit, Investment, Percent U.S. Agency US Government Corporations and Agencies Securities [Member] Receivable [Domain] Receivable [Domain] Issuance of stock, net of issuance costs Stock Issued During Period, Value, New Issues Payments for asset retirement obligations Payments For Asset Retirement Obligations Payments For Asset Retirement Obligations Shares, Outstanding Beginning balance (in shares) Ending balance (in shares) Shares, Outstanding Schedule of Components of Income Tax Expense (Benefit) Schedule of Components of Income Tax Expense (Benefit) [Table Text Block] Issuance of restricted common stock Stock Issued During Period, Value, Restricted Stock Award, Gross Term Loan Facility Line of Credit [Member] Senior Notes Senior Notes [Member] Level 3 Fair Value, Inputs, Level 3 [Member] Long-Term debt fair value adjustment Long-TermDebtFairValueAdjustment [Member] Long-Term debt fair value adjustment recorded in association with the merger. Equity securities Equity Securities [Member] Accounting Policies [Abstract] Accounting Policies [Abstract] Foreign governments Debt Security, Government, Non-US [Member] Carrying charges application rate PublicUtilitiesRequestedApplicationOfCarryingChargesPercentage Public utilities requested application of carrying charges percentage Issuance of stock, net of issuance costs (in shares) Stock Issued During Period, Shares, New Issues Number of segments Number of Reportable Segments Federal Current Federal Tax Expense (Benefit) Letters of Credit Letters of Credit Outstanding, Amount Public Utilities, Regulatory Proceeding [Domain] Public Utilities, Regulatory Proceeding [Domain] Public Utilities, Recovery Mechanism Percent for Fuel Cost Public Utilities, Recovery Mechanism Percent for Fuel Cost Public Utilities, Recovery Mechanism Percent for Fuel Cost Document Transition Report Document Transition Report Common stock Common Stock, Value, Issued Disaggregation of Revenue [Line Items] Disaggregation of Revenue [Line Items] Total Other Income (Expense), Net Total Other Expense, Net Nonoperating Income (Expense) February 2021 winter weather event February2021WinterWeatherEventRegulatoryLiability [Member] Discloses the amount of regulatory liability arising from the deferral of increased wholesale revenues earned during the February 2021 winter weather event. Post-Retirement Benefits Other Postretirement Benefits Plan [Member] Annual revenue increase (decrease) approved Public Utilities, Approved Rate Increase (Decrease), Amount Commitments and Contingencies (Note $10) Commitments and Contingencies Equity Securities - Fifth Fund Equity Securities - Fifth Fund [Member] Equity Securities - Fifth Fund [Member] Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Entity Emerging Growth Company Entity Emerging Growth Company Fuel inventory Energy Related Inventory, Coal Allowance for credit losses Allowance for credit losses Accounts Receivable, Allowance for Credit Loss, Current Billed Billed Revenues [Member] ICFR Auditor Attestation Flag ICFR Auditor Attestation Flag Receivables [Abstract] Receivables [Abstract] Planned Capacity of Investment in Renewable Generation Planned Capacity of Investment in Renewable Generation Planned Capacity of Investment in Renewable Generation Transmission delivery charge Transmission Delivery Charge [Member] Transmission Delivery Charge [Member] Antidilutive Securities, Name [Domain] Antidilutive Securities, Name [Domain] Ownership [Axis] Ownership [Axis] Legal Entity [Axis] Legal Entity [Axis] Cover [Abstract] Cover [Abstract] Due from Related Parties, Current Due from Related Parties, Current Total Operating Expenses Costs and Expenses Class of Stock [Axis] Class of Stock [Axis] Schedule of Costs of Retirement Plans Schedule of Costs of Retirement Plans [Table Text Block] OTHER ASSETS: Investments And Other Assets [Abstract] Income tax expense Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, Tax Income Tax Contingency [Line Items] Income Tax Contingency [Line Items] Estimated loss contingency portion not accrued (up to) EstimatedLossContingencyPortionNotAccrued Estimated loss contingency portion not accrued Domestic Geographic Distribution, Domestic [Member] Related party receivables Accounts Receivable, Related Parties, Current Net money pool lending Proceeds from Collection of Advance to Affiliate 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 Prepaid expenses Prepaid Expense and Other Assets, Current COMPREHENSIVE INCOME Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract] Short-term Debt [Line Items] Short-term Debt [Line Items] Dividends declared on common stock (in dollars per share) Common Stock, Dividends, Per Share, Declared Entity [Domain] Entity [Domain] Total revenue from contracts with customers Revenue from Contract with Customer, Excluding Assessed Tax Defined benefit pension plans Defined Benefit Pension Plans [Abstract] Defined Benefit Pension Plans [Abstract] Proceeds from investment in corporate-owned life insurance Proceeds from investment in corporate-owned life insurance Proceeds from Life Insurance Policy Cash dividends paid Payments of Dividends Equity Securities - Fourth Fund Equity Securities - Fourth Fund [Member] Equity Securities - Fourth Fund [Member] Current income taxes Current Income Tax Expense (Benefit), Continuing Operations [Abstract] FERC 2021 TFR Proceeding FERC 2021 TFR Proceeding [Member] FERC 2021 TFR Proceeding 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 Hierarchy and NAV [Axis] Fair Value Hierarchy and NAV [Axis] Book Value Reported Value Measurement [Member] Document Quarterly Report Document Quarterly Report Alternative investments fund Alternative investments fund Alternative Investment Fund [Member] Alternative Investment Fund [Member] Common Stock Common Stock Common Stock [Member] INCOME FROM OPERATIONS Operating Income (Loss) Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Regulatory liabilities Regulatory Liability, Noncurrent Lease liability recorded in other current liabilities Operating Lease, Liability, Current 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] Less:  Comprehensive income attributable to noncontrolling interest Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Noncontrolling Interest Debt instrument, debt default, threshold Debt Instrument, Debt Default, Threshold Debt Instrument, Debt Default, Threshold Increase (Decrease) in Stockholders' Equity [Roll Forward] Increase (Decrease) in Stockholders' Equity [Roll Forward] Document Fiscal Year Focus Document Fiscal Year Focus 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] Non-service cost component of net benefit cost Non Service Cost Component Of Net Benefit Cost Non Service Cost Component Of Net Benefit Cost Non-cash compensation Share-based Payment Arrangement, Noncash Expense 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] Total Other Assets Regulated Entity, Other Assets, Noncurrent Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value Public Utilities, Requested Refund Increase (Decrease), Amount Public Utilities, Requested Refund Increase (Decrease), Amount Public Utilities, Requested Refund Increase (Decrease), Amount Regulatory assets Regulatory Assets CASH, CASH EQUIVALENTS AND RESTRICTED CASH: Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect [Abstract] Defined benefit plan basis point change in discount rate DefinedBenefitPlanChangeInDiscountRate DefinedBenefitPlanChangeInDiscountRate Related party transaction Related Party Transaction, Amounts of Transaction Long-term Debt, Type [Domain] Long-term Debt, Type [Domain] International Geographic Distribution, Foreign [Member] Regulatory Asset, Amortization Period Regulatory Asset, Amortization Period Entity Information [Line Items] Entity Information [Line Items] Compensation expense recognized APIC, Share-based Payment Arrangement, Restricted Stock Unit, Increase for Cost Recognition Long-term debt Long-term Debt, Fair Value Issuance of stock for compensation and reinvested dividends Stock Issued Other investing activities Payments for (Proceeds from) Other Investing Activities Additions to property, plant and equipment Payments to Acquire Property, Plant, and Equipment Other Other Liabilities, Current Effect of: Effect Of [Abstract] Effect Of [Abstract] Weighted Average Interest Rate on Short-Term Borrowings Line of Credit Facility, Interest Rate at Period End Contributions by employer Defined Benefit Plan, Plan Assets, Contributions by Employer Maximum Maximum [Member] Effective Income Tax Rate Reconciliation, Percent [Abstract] Effective Income Tax Rate Reconciliation, Percent [Abstract] Components of Income Tax Expense (Benefit), Continuing Operations [Abstract] Components of Income Tax Expense (Benefit), Continuing Operations [Abstract] Unbilled Unbilled Revenues [Member] Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Table] Fair Value, Measured on Recurring Basis, Gain (Loss) Included in Earnings [Table] Total recognized in net periodic benefit costs and OCI or regulatory asset/liability Defined Benefit Plan, Amount Recognized in Net Periodic Benefit Cost (Credit) and Other Comprehensive (Income) Loss, before Tax 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] CASH FLOWS FROM (USED IN) FINANCING ACTIVITIES: Net Cash Provided by (Used in) Financing Activities [Abstract] Total Evergy, Inc. Shareholders' Equity Stockholders' Equity Attributable to Parent Accounts, Notes, Loans and Financing Receivable by Billing Status, Type [Axis] Billing Status, Type [Axis] AEP Transmission Holding Company, LLC AEP Transmission Holding Company, LLC [Member] AEP Transmission Holding Company, LLC 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] 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. Common stock - shares issued (in shares) Common Stock, Shares, Issued City Area Code City Area Code Supplemental Cash Flow Information Schedule of Cash Flow, Supplemental Disclosures [Table Text Block] Goodwill and Intangible Assets Disclosure [Abstract] Goodwill and Intangible Assets Disclosure [Abstract] Schedule of Defined Benefit Plan, Assumptions Defined Benefit Plan, Assumptions [Table Text Block] Entity Address, City or Town Entity Address, City or Town Operating Expenses and Capital Costs Billed Operating Expenses And Capital Costs Billed [Member] Operating Expenses and Capital Costs Billed [Member] Unrealized gains (losses) Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss) Public Utilities, Regulatory Proceeding [Axis] Public Utilities, Regulatory Proceeding [Axis] 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 Schedule of Expected Benefit Payments Schedule of Expected Benefit Payments [Table Text Block] Evergy, Inc. Shareholders' Equity: Evergy, Inc. Shareholders' Equity: Stockholders' Equity Attributable to Parent [Abstract] Retirement Plan Type [Axis] Retirement Plan Type [Axis] Schedule of Short-term Debt [Table] Schedule of Short-term Debt [Table] Measurement Frequency [Domain] Measurement Frequency [Domain] Jointly Owned Utility Plant [Axis] Jointly Owned Utility Plant [Axis] Total Current Income Tax Expense (Benefit) 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. Interest expense Interest Expense Weighted Average Interest Rate on Term Loan Facility Short-term Debt, Weighted Average Interest Rate, at Point in Time Deferred income taxes Deferred Income Tax Expense (Benefit), Continuing Operations [Abstract] Borrowing From Mid June Through Expiration Borrowing From Mid June Through Mid November [Member] Borrowing From Mid June Through Mid November [Member] Net periodic benefit costs (income) Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Amortization of deferred refueling outage Amortization Of Deferred Refueling Outage Costs Amortization Of Deferred Refueling Outage Costs Retained earnings Retained Earnings (Accumulated Deficit) Schedule of Defined Benefit Plans Disclosures [Table] Schedule of Defined Benefit Plans Disclosures [Table] RSUs Restricted Stock Units (RSUs) [Member] Statement of Stockholders' Equity [Abstract] Statement of Stockholders' Equity [Abstract] Entity Filer Category Entity Filer Category Investment earnings (loss) Investment loss Gain (Loss) on Investments 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] Issuance of restricted common stock AdjustmentsToAdditionalPaidInCapitalShareBasedCompensationRestrictedStockUnitsIssuance Adjustments To Additional Paid In Capital Share Based Compensation Restricted Stock Units Issuance Income Statement [Abstract] Income Statement [Abstract] Recommended return on equity Recommended return on equity Percentage of return on equity recommended by staff of the state commission Fair Value Estimate of Fair Value Measurement [Member] Entity Registrant Name Entity Registrant Name Asset Class [Domain] Asset Class [Domain] SHORT-TERM BORROWINGS AND SHORT-TERM BANK LINES OF CREDIT Short-term Debt [Text Block] 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] Core bond fund Core Bond Fund [Member] Core Bond Fund [Member] Basis of Presentation Basis of Presentation and Significant Accounting Policies [Text Block] Related Party Transaction [Axis] Related Party Transaction [Axis] Issuance of restricted common stock (in shares) Stock Issued During Period, Shares, Restricted Stock Award, Gross Income tax expense Income tax expense Income Tax Expense (Benefit) Total Equity Beginning balance Ending balance Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Receivables, net of allowance for credit losses of $27.1 and $32.9, respectively Receivables, net of allowance for credit losses of $10.7 and $13.0, respectively Receivables, net of allowance for credit losses of $11.1 and $13.3, respectively Total Accounts Receivable, after Allowance for Credit Loss, Current Amendment Flag Amendment Flag Unsecured Debt Unsecured Debt [Member] Proceeds from long-term debt Proceeds from Issuance of Long-term Debt Equity Components [Axis] Equity Components [Axis] Dividends Payable [Table] Dividends Payable [Table] Entity Tax Identification Number Entity Tax Identification Number Fair Value Disclosures [Abstract] Fair Value Disclosures [Abstract] Antidilutive Securities [Axis] Antidilutive Securities [Axis] Document Fiscal Period Focus Document Fiscal Period Focus Total Current Assets Assets, Current Disaggregation of Revenue [Table] Disaggregation of Revenue [Table] AVERAGE COMMON SHARES OUTSTANDING Common Shares Outstanding Weighted Average Number of Shares Outstanding Reconciliation [Abstract] Non-qualified benefit obligations UnfundedAccumulatedBenefitObligationForNonQualifiedPlans The unfunded accumulated benefit obligation related to non-qualified benefit plans. Receivables Billing Status [Domain] Receivables Billing Status [Domain] Reclassification to expenses, net of tax Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after 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 Transmission line length Transmission Line Length Transmission Line Length Federal Deferred Federal Income Tax Expense (Benefit) 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] Other income Other Nonoperating Income Statement of Financial Position [Abstract] Statement of Financial Position [Abstract] 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 Schedule of Related Party Receivables and Payables Schedule of Related Party Transactions [Table Text Block] Current maturities of long-term debt Long-term Debt, Current Maturities Property, Plant and Equipment, Type [Domain] Long-Lived Tangible Asset [Domain] Jointly Owned Utility Plant [Domain] Jointly Owned Utility Plant [Domain] 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 Entity Public Float Entity Public Float Stock compensation Effective Income Tax Rate Reconciliation, Nondeductible Expense, Share-based Payment Arrangement, Percent Income from corporate-owned life insurance Income from corporate-owned life insurance Income From Corporate Owned Life Insurance Income From Corporate Owned Life Insurance Equity Component [Domain] Equity Component [Domain] 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 Other Stockholders' Equity, Other Schedule of Net Funded Status Schedule of Net Funded Status [Table Text Block] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Schedule of Accounts, Notes, Loans and Financing Receivable [Table] Variable Interest Entity [Line Items] Variable Interest Entity [Line Items] Related Party Transaction, Due from (to) Related Party, Current [Abstract] Related Party Transaction, Due from (to) Related Party, Current [Abstract] Accrued taxes Increase (Decrease) in Accrued Taxes Payable Statement [Line Items] Statement [Line Items] Other current liabilities Increase (Decrease) in Other Current Liabilities Net gain on derivative hedging instruments Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax 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. Dividends Payable [Line Items] Dividends Payable [Line Items] Share forward agreement Derivative Instruments Not Designated as Hedging Instruments, Asset, at Fair Value Short-term Debt, Type [Axis] Short-term Debt, Type [Axis] Retirement Plan Type [Domain] Retirement Plan Type [Domain] Derivative hedging activity Derivative Hedging Activity [Abstract] Derivative Hedging Activity [Abstract] Schedule of Allocation of Plan Assets Schedule of Allocation of Plan Assets [Table Text Block] Schedule of Carrying Value and Fair Value of Debt Instruments Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block] Valuation allowance Effective Income Tax Rate Reconciliation, Change in Deferred Tax Assets Valuation Allowance, Percent Counterparty Name [Domain] Counterparty Name [Domain] February 2021 winter weather event February2021WinterWeatherEvent [Member] Discloses the amount of regulatory asset arising from deferred extraordinary fuel and purchased power costs incurred as a result of the February 2021 winter weather event. Debt Disclosure [Abstract] Debt Disclosure [Abstract] Level 2 Fair Value, Inputs, Level 2 [Member] Asset retirement obligations Asset Retirement Obligation, Current Geographic Distribution [Domain] Geographic Distribution [Domain] Schedule of Health Care Cost Trend Rates Schedule of Health Care Cost Trend Rates [Table Text Block] Property, Plant and Equipment, Type [Axis] Long-Lived Tangible Asset [Axis] Related party payables Accounts Payable, Related Parties, Current 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] Customer [Axis] Customer [Axis] Fuel inventory and supplies Fuel inventory and supplies Energy Related Inventory Senior Notes Due 2033 EMW Senior Notes Series B due 2033 EMW [Member] Senior Notes Series B due 2033 EMW. Annual revenue increase (decrease) related to rebasing, property tax and credit loss expense, storm reserve and return on unrecovered investment PublicUtilitiesRequestedRateIncreaseDecreaseAmountOther Public utilities requested rate increase decrease amount rebasing fuel purchased power expense proprty tax and credit loss expense tracker storm reserve and return on unrecovered investment PENSION PLANS AND POST-RETIREMENT BENEFITS Retirement Benefits [Text Block] Schedule of Earnings Per Share, Basic and Diluted Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Asset Class [Axis] Asset Class [Axis] Document Annual Report Document Annual Report Title of 12(b) Security Title of 12(b) Security Senior Notes Series B due 2033 EMW SeniorNotesSeriesB3.01PercentDue2033EMW [Member] Senior Notes Series B 3.01 percent due 2033 EMW Unamortized investment tax credits Accumulated Deferred Investment Tax Credit Issuance of common stock Proceeds from Issuance of Common Stock TOTAL ASSETS Assets Investment, Name [Domain] Investment, Name [Domain] Net deferred income taxes and credits Deferred Income Taxes and Tax Credits Distributions to shareholders of noncontrolling interests Payments to Noncontrolling Interests Common stock - shares authorized (in shares) Common Stock, Shares Authorized Interest, net of amount capitalized Interest Paid, Excluding Capitalized Interest, Operating Activities Equity securities evrg_OtherEquityInvestmentFairValueDisclosure OtherEquityInvestmentFairValueDisclosure Maximum amount of outstanding principal under receivables agreement Maximum Amount Of Outstanding Principal Under Receivables Agreement Maximum amount of outstanding principal under receivables agreement Document Type Document Type Non-controlling interests Noncontrolling Interest [Member] Fuel recovery mechanisms Deferred Fuel Costs [Member] Depreciation and amortization Depreciation and amortization Depreciation, Depletion and Amortization, Nonproduction Interest rate Debt Instrument, Interest Rate, Stated Percentage Schedule of Receivables Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block] Less: Net income attributable to noncontrolling interests Net Income (Loss) Attributable to Noncontrolling Interest 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. Total Long-Term Liabilities Liabilities, Noncurrent Cash Borrowings Cash Borrowings Revolving Credit Facility [Member] Unfunded Commitments Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments Measurement Frequency [Axis] Measurement Frequency [Axis] Term Loan Facility Borrowings Short-term Debt Cash Flows from Operating Activities Net Cash Provided by (Used in) Operating Activities Accounts, Notes, Loans and Financing Receivable [Line Items] Accounts, Notes, Loans and Financing Receivable [Line Items] Wolf Creek Jointly Owned Nuclear Power Plant [Member] Schedule of Debt Schedule of Debt [Table Text Block] Fair Value, Recurring and Nonrecurring [Table] Fair Value, Recurring and Nonrecurring [Table] Funded by trusts containing assets SegregatedAssetsForNonQualifiedBenefitPlans SegregatedAssetsForNonQualifiedBenefitPlans Costs probable of refund 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. Schedule of Long-term Debt Instruments [Table] Schedule of Long-term Debt Instruments [Table] Changes In Uncertain Tax Positions, Net EffectiveIncomeTaxRateReconciliationChangesInUncertainTaxPositionsNet Effective Income Tax Rate Reconciliation, Changes In Uncertain Tax Positions, Net Non-controlling interest Effective Income Tax Rate Reconciliation, Noncontrolling Interest Income (Loss), Percent 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 Borrowings From Mid October Through Mid June Borrowings From Mid October Through Mid June [Member] Borrowings From Mid October Through Mid June [Member] Basic (in shares) Weighted average equivalent common shares outstanding - basic (in shares) Weighted Average Number of Shares Outstanding, Basic Diluted earnings per common share (in dollars per share) Earnings Per Share, Diluted Earnings Per Share, Diluted Due to Related Parties, Current Due to Related Parties, Current 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. Add: effect of dilutive securities (in shares) Weighted Average Number Diluted Shares Outstanding Adjustment 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] Service cost Defined Benefit Plan, Service Cost 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 Income taxes, net of refunds Income Taxes Paid, Net Other Other Revenue Revenue other than from contracts with customers. COMPREHENSIVE INCOME COMPREHENSIVE INCOME Comprehensive Income (Loss), Net of Tax, Attributable to Parent Regulatory Liability [Domain] Regulatory Liability [Domain] Cash Flows from Financing Activities Net Cash Provided by (Used in) Financing Activities Derivative hedging activity Other Comprehensive Income (Loss), Net of Tax [Abstract] Actuarial (gain) loss Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Including Portion Attributable to Noncontrolling Interest [Member] Schedule of Amounts Recognized in Balance Sheet Schedule of Amounts Recognized in Balance Sheet [Table Text Block] Deferred income taxes Deferred Income Tax Liabilities, Net Related Party Transaction [Line Items] Related Party Transaction [Line Items] RSUs with Service Requirements Restricted Stock Units With Service Requirements [Member] Restricted Stock Units With Service Requirements Total nuclear decommissioning trust Decommissioning Fund Investments, Fair Value 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 Retirements of long-term debt of variable interest entities Retirements of Long Term Debt Of VIEs Retirements of Long Term Debt Of VIEs AFUDC equity EffectiveIncomeTaxRateReconciliationAFUDCEquity Effective Income Tax Rate Reconciliation, AFUDC Equity Corporate bonds Corporate Debt Securities [Member] Schedule of Effective Income Tax Rate Reconciliation Schedule of Effective Income Tax Rate Reconciliation [Table Text Block] FAIR VALUE MEASUREMENTS Fair Value Disclosures [Text Block] Accounts payable Accounts Payable, Current Variable Interest Entities Variable Interest Entity, Primary Beneficiary [Member] 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 Allowance for equity funds used during construction Increase (Decrease) in Allowance for Equity Funds Used During Construction Notes payable and commercial paper Short-term Bank Loans and Notes Payable Property, plant and equipment additions Non Cash Property Plant And Equipment Additions, Gross Non-cash property, plant and equipment additions, Gross Federal or state tax rate change Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent Schedule of Fair Value of Assets and Liabilities Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] 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 Officer compensation limitation EffectiveIncomeTaxRateReconciliationOfficerCompensationLimitation Officer compensation limitation AOCI AOCI Attributable to Parent [Member] Dividends payable Dividends Payable Regulatory Asset [Domain] Regulatory Asset [Domain] Contributions to plans remainder of year Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year Other Other Trust Assets [Member] Other assets within the trust fund. Document Period End Date Document Period End Date Number of reporting units Number of Reporting Units 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. Entity Central Index Key Entity Central Index Key Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items] Transmission line electrical potential Transmission Line Electrical Potential Transmission Line Electrical Potential Consolidated Entities [Domain] Consolidated Entities [Domain] State income taxes Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent State Deferred State and Local Income Tax Expense (Benefit) Summary of Property, Plant and Equipment Property, Plant and Equipment [Table Text Block] EQUITY: Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Non-cash investing transactions: Cash Flow, Noncash Investing and Financing Activities Disclosure [Abstract] Recommended increase (decrease) to revenues Recommended increase (decrease) to revenues Amount of rate increase (decrease) recommended by staff of the state commission. PROPERTY, PLANT AND EQUIPMENT, NET Property, plant and equipment, net Property, Plant and Equipment, Net AOCI - Net gains (losses) on cash flow hedges AOCI Including Portion Attributable to Noncontrolling Interest [Member] Other Other Liabilities, Noncurrent Combination debt/equity/other fund Debt Equity Other Fund [Member] Debt Equity Other Fund [Member] Nuclear fuel, net Nuclear Fuel [Member] 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. Debt Instrument [Line Items] Debt Instrument [Line Items] Retirements of long-term debt Retirements of long-term debt Repayments of Long-term Debt Trading Symbol Trading Symbol Evergy, Inc. Evergy Evergy [Member] Evergy [Member] 2021 MPSC Winter Weather Qualified Extraordinary Costs Securitization 2021MPSCWinterWeatherQualifiedExtraordinaryCostsSecuritization [Member] 2021 MPSC Winter Weather Qualified Extraordinary Costs Securitization Property, plant and equipment, gross Property, Plant and Equipment, Gross Beginning balance January 1 Ending balance June 30 Accounts Receivable, Allowance for Credit Loss Related Party Transaction [Domain] Related Party Transaction [Domain] Changes in other assets Increase (Decrease) in Other Operating Assets OPERATING REVENUES Revenues Revenues Pollution Control Bonds Pollution Control Bonds [Member] Pollution Control Bonds [Member] Master Credit Facility Line of Credit Facility, Current Borrowing Capacity Operating and maintenance Utilities Operating Expense, Maintenance and Operations Investment in corporate-owned life insurance Investment in corporate-owned life insurance Payment to Acquire Life Insurance Policy, Investing Activities Warrant Warrant [Member] OPERATING EXPENSES: Costs and Expenses [Abstract] AdditionalPrincipalFirstMortgageBondsAvailableToBeIssued AdditionalPrincipalFirstMortgageBondsAvailableToBeIssued Principal amount of additional first mortgage bonds available to be issued under th most restrictive mortgage provisions. Income tax benefit Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, Tax Long-term debt, net Long-term Debt, Excluding Current Maturities Regulatory Liability, Amortization Period Regulatory Liability, Amortization Period Schedule of Related Party Transactions, by Related Party [Table] Schedule of Related Party Transactions, by Related Party [Table] Entity Current Reporting Status Entity Current Reporting Status BASIC AND DILUTED EARNINGS PER AVERAGE COMMON SHARE OUTSTANDING ATTRIBUTABLE TO EVERGY, INC. (see Note 1) Earnings Per Share, Basic and Diluted [Abstract] Income Tax Receivable Income Tax Receivable [Member] Income Tax Receivable [Member] Effective income tax rate Effective Income Tax Rate Reconciliation, Percent Entities [Table] Entities [Table] 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. NET INCOME Net income NET INCOME Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Contributions to plans in next year Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year Customer accounts receivable Accounts Receivable, before Allowance for Credit Loss, Current Counterparty Name [Axis] Counterparty Name [Axis] Commercial Electric Utility Customer Class Commercial [Member] Commercial customer class from which revenues are generated by the regulated sale of electricity [Member] Regulatory assets Regulatory Assets, Noncurrent Mortgage Bonds Due 2032 EMW Mortgage Bonds Due 2032 EMW [Member] Mortgage Bonds Due 2032 EMW Construction work in progress Construction in Progress [Member] Federal Energy Regulatory Commission Federal Energy Regulatory Commission [Member] Federal Energy Regulatory Commission [Member] Beginning of period End of period Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Estimated refund on earnings over approved return on equity PublicUtilitiesEstimatedRefundOnEarningsOverApprovedReturnOnEquity Public Utilities Estimated Refund On Earnings Over Approved Return On Equity Common stock - par value (in dollars per share) Common Stock, Par or Stated Value Per Share Defined Benefit Plan Disclosure [Line Items] Defined Benefit Plan Disclosure [Line Items] Supplies Energy Related Inventory, Supplies Energy Related Inventory, Supplies Statement of Comprehensive Income [Abstract] Statement of Comprehensive Income [Abstract] Accrued taxes Taxes Payable, Current CURRENT ASSETS: Assets, Current [Abstract] Other financing activities Proceeds from (Payments for) Other Financing Activities Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Table] Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Table] 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 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 Entity Address, Postal Zip Code Entity Address, Postal Zip Code SPP network transmission costs SPPNetworkTransmissionCosts Cost incurred for SPP transmission costs Purchase of securities - trusts Payments to Acquire Investments to be Held in Decommissioning Trust Fund Diluted (in shares) Diluted average number of common shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Diluted Total other comprehensive income Other Comprehensive Income (Loss), Net of Tax Fair Value, Measurements, Recurring Fair Value, Recurring [Member] EIRR Bonds Series 2007A and 2007B due 2038 EM EERR Bonds 2875 Percent Series 2008 EM [Member] 2.875 percent EIRR bonds due 2008 EM. TAXES Income Tax Disclosure [Text Block] Accrued interest Interest Payable, Current Related Party [Domain] Related Party [Domain] Long-term Debt, Type [Axis] Long-term Debt, Type [Axis] RATE MATTERS AND REGULATION Public Utilities Disclosure [Text Block] Write-offs Accounts Receivable, Allowance for Credit Loss, Writeoff Schedule of Net Benefit Costs Schedule of Net Benefit Costs [Table Text Block] Borrowing From Mid June Through Mid October Borrowing From Mid June Through Mid October [Member] Borrowing From Mid June Through Mid October Measurement Basis [Axis] Measurement Basis [Axis] Statement of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Asset retirement obligations Asset Retirement Obligations, Noncurrent Credit Facility [Axis] Credit Facility [Axis] Entity Address, Address Line One Entity Address, Address Line One Cash Flows used in Investing Activities Net Cash Provided by (Used in) Investing Activities Portion at Fair Value Measurement [Member] Portion at Fair Value Measurement [Member] Other receivables Other Receivables, Gross, Current Interest of VIEs Interest Paid, Including Capitalized Interest, Operating and Investing Activities Changes in working capital items: Increase (Decrease) in Operating Capital [Abstract] Accumulated depreciation Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment CASH FLOWS FROM (USED IN) OPERATING ACTIVITIES: Net Cash Provided by (Used in) Operating Activities [Abstract] Principles of Consolidation Consolidation, Policy [Policy Text Block] Entity Shell Company Entity Shell Company Industrial Electric Utility Customer Class Industrial [Member] Industrial customer class from which revenues are generated by the regulated sale of electricity [Member] Schedule of Short-term Debt Schedule of Short-term Debt [Table Text Block] Deferred customer programs Deferred Customer Programs [Member] Discloses the amount of regulatory asset arising from deferred customer program. Total Current Liabilities Liabilities, Current Class of Stock [Domain] Class of Stock [Domain] Senior Notes Due 2022 Senior Notes 5.292 Percent Series Due 2022 [Member] Senior Notes 5.292 Percent Series Due 2022. 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. Regulatory Proceedings [Table] Public Utilities General Disclosures [Table] Line of credit, maximum borrowing capacity Line of Credit Facility, Maximum Borrowing Capacity Dividend equivalents declared Dividend, Share-based Payment Arrangement Rabbi trust: Rabbi trusts - equity securities Rabbi Trusts [Member] Rabbi Trusts [Member] Ownership [Domain] Ownership [Domain] 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] Current Fiscal Year End Date Current Fiscal Year End Date 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] Taxes other than income tax Taxes, Miscellaneous Debt Instrument, Name [Domain] Debt Instrument, Name [Domain] Regulatory liabilities Regulatory Liability, Current Other assets Other Assets, Current Statement [Table] Statement [Table] Analog meter unrecovered investment Analog Meter Unvrecovered Investment [Member] Discloses the deferral of unrecovered investment of retired analog meters. Statistical Measurement [Axis] Statistical Measurement [Axis] 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] Subsequent Event Subsequent Event [Member] FERC 2022 TFR Proceeding FERC2022TFRProceeding [Member] FERC 2022 TFR Proceeding Summary Of Accounting Policies [Line Items] Summary Of Accounting Policies [Line Items] [Line Items] for Summary Of Accounting Policies [Table] Goodwill Goodwill Goodwill Other receivables, contracts with customers Other Receivables, Contracts With Customers The amount of other receivables resulting from contracts with customers. Noncontrolling Interests Stockholders' Equity Attributable to Noncontrolling Interest Evergy Kansas Central Evergy Kansas Central Inc [Member] Utility operating in Kansas. NAV Fair Value Measured at Net Asset Value Per Share [Member] Transource Energy, LLC Transource Energy, LLC [Member] Transource Energy, LLC Collateralized note payable Transfers Accounted for as Secured Borrowings, Associated Liabilities, Carrying Amount Fuel Inventory and Supplies Inventory, Policy [Policy Text Block] Other expense Other expense Other expense Other Nonoperating Expense 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] Pension Benefits Pension Plan [Member] NAV, extension term Fair Value, Investments, Entities That Calculate Net Asset Value Extension Term Fair Value, Investments, Entities that Calculate Net Asset Value, Extension Term Subsequent Event Type [Axis] Subsequent Event Type [Axis] Regulated Operations [Abstract] Regulated Operations [Abstract] RELATED PARTY TRANSACTIONS AND RELATIONSHIPS Related Party Transactions Disclosure [Text Block] Geographic Distribution [Axis] Geographic Distribution [Axis] Total InvestmentTaxCreditTotalNet Investment Tax Credit Total Net Inventory [Line Items] Inventory [Line Items] Total Deferred Income Tax Expense (Benefit) LONG-TERM DEBT Long-term Debt [Text Block]