3.25.4 html 1387 871 1 false 368 0 false 26 false false R1.htm 0000001 - Document - Cover Page Sheet http://www.wecenergygroup.com/role/CoverPage Cover Page Cover 1 false false R2.htm 0000002 - Document - Audit Information Sheet http://www.wecenergygroup.com/role/AuditInformation Audit Information Cover 2 false false R3.htm 9952151 - Statement - Consolidated Income Statements Sheet http://www.wecenergygroup.com/role/ConsolidatedIncomeStatements Consolidated Income Statements Statements 3 false false R4.htm 9952152 - Statement - Consolidated Statements of Comprehensive Income Sheet http://www.wecenergygroup.com/role/ConsolidatedStatementsofComprehensiveIncome Consolidated Statements of Comprehensive Income Statements 4 false false R5.htm 9952153 - Statement - Consolidated Balance Sheets Sheet http://www.wecenergygroup.com/role/ConsolidatedBalanceSheets Consolidated Balance Sheets Statements 5 false false R6.htm 9952154 - Statement - Consolidated Balance Sheets (Parenthetical) Sheet http://www.wecenergygroup.com/role/ConsolidatedBalanceSheetsParenthetical Consolidated Balance Sheets (Parenthetical) Statements 6 false false R7.htm 9952155 - Statement - Consolidated Statements of Cash Flows Sheet http://www.wecenergygroup.com/role/ConsolidatedStatementsofCashFlows Consolidated Statements of Cash Flows Statements 7 false false R8.htm 9952156 - Statement - Consolidated Statement of Cash Flows (Parenthetical) Sheet http://www.wecenergygroup.com/role/ConsolidatedStatementofCashFlowsParenthetical Consolidated Statement of Cash Flows (Parenthetical) Statements 8 false false R9.htm 9952157 - Statement - Consolidated Statements of Equity Sheet http://www.wecenergygroup.com/role/ConsolidatedStatementsofEquity Consolidated Statements of Equity Statements 9 false false R10.htm 9952158 - Statement - Consolidated Statements of Equity (Parenthetical) Sheet http://www.wecenergygroup.com/role/ConsolidatedStatementsofEquityParenthetical Consolidated Statements of Equity (Parenthetical) Statements 10 false false R11.htm 9952159 - Disclosure - Summary of Significant Accounting Policies Sheet http://www.wecenergygroup.com/role/SummaryofSignificantAccountingPolicies Summary of Significant Accounting Policies Notes 11 false false R12.htm 9952160 - Disclosure - Acquisitions Sheet http://www.wecenergygroup.com/role/Acquisitions Acquisitions Notes 12 false false R13.htm 9952161 - Disclosure - Dispositions Sheet http://www.wecenergygroup.com/role/Dispositions Dispositions Notes 13 false false R14.htm 9952162 - Disclosure - Operating Revenues Sheet http://www.wecenergygroup.com/role/OperatingRevenues Operating Revenues Notes 14 false false R15.htm 9952163 - Disclosure - Credit Losses Sheet http://www.wecenergygroup.com/role/CreditLosses Credit Losses Notes 15 false false R16.htm 9952164 - Disclosure - Regulatory Assets and Liabilities Sheet http://www.wecenergygroup.com/role/RegulatoryAssetsandLiabilities Regulatory Assets and Liabilities Notes 16 false false R17.htm 9952165 - Disclosure - Property, Plant, and Equipment Sheet http://www.wecenergygroup.com/role/PropertyPlantandEquipment Property, Plant, and Equipment Notes 17 false false R18.htm 9952166 - Disclosure - Jointly Owned Utility Facilities Sheet http://www.wecenergygroup.com/role/JointlyOwnedUtilityFacilities Jointly Owned Utility Facilities Notes 18 false false R19.htm 9952167 - Disclosure - Asset Retirement Obligations Sheet http://www.wecenergygroup.com/role/AssetRetirementObligations Asset Retirement Obligations Notes 19 false false R20.htm 9952168 - Disclosure - Goodwill and Intangibles Sheet http://www.wecenergygroup.com/role/GoodwillandIntangibles Goodwill and Intangibles Notes 20 false false R21.htm 9952169 - Disclosure - Common Equity Sheet http://www.wecenergygroup.com/role/CommonEquity Common Equity Notes 21 false false R22.htm 9952170 - Disclosure - Preferred Stock Sheet http://www.wecenergygroup.com/role/PreferredStock Preferred Stock Notes 22 false false R23.htm 9952171 - Disclosure - Short-Term Debt and Lines of Credit Sheet http://www.wecenergygroup.com/role/ShortTermDebtandLinesofCredit Short-Term Debt and Lines of Credit Notes 23 false false R24.htm 9952172 - Disclosure - Long-Term Debt Sheet http://www.wecenergygroup.com/role/LongTermDebt Long-Term Debt Notes 24 false false R25.htm 9952173 - Disclosure - Leases Sheet http://www.wecenergygroup.com/role/Leases Leases Notes 25 false false R26.htm 9952174 - Disclosure - Income Taxes Sheet http://www.wecenergygroup.com/role/IncomeTaxes Income Taxes Notes 26 false false R27.htm 9952175 - Disclosure - Fair Value Measurements Sheet http://www.wecenergygroup.com/role/FairValueMeasurements Fair Value Measurements Notes 27 false false R28.htm 9952176 - Disclosure - Derivative Instruments Sheet http://www.wecenergygroup.com/role/DerivativeInstruments Derivative Instruments Notes 28 false false R29.htm 9952177 - Disclosure - Guarantees Sheet http://www.wecenergygroup.com/role/Guarantees Guarantees Notes 29 false false R30.htm 9952178 - Disclosure - Employee Benefits Sheet http://www.wecenergygroup.com/role/EmployeeBenefits Employee Benefits Notes 30 false false R31.htm 9952179 - Disclosure - Investment in Transmission Affiliates Sheet http://www.wecenergygroup.com/role/InvestmentinTransmissionAffiliates Investment in Transmission Affiliates Notes 31 false false R32.htm 9952180 - Disclosure - Segment Information Sheet http://www.wecenergygroup.com/role/SegmentInformation Segment Information Notes 32 false false R33.htm 9952181 - Disclosure - Variable Interest Entities Sheet http://www.wecenergygroup.com/role/VariableInterestEntities Variable Interest Entities Notes 33 false false R34.htm 9952182 - Disclosure - Commitments and Contingencies Sheet http://www.wecenergygroup.com/role/CommitmentsandContingencies Commitments and Contingencies Notes 34 false false R35.htm 9952183 - Disclosure - Supplemental Cash Flow Information Sheet http://www.wecenergygroup.com/role/SupplementalCashFlowInformation Supplemental Cash Flow Information Notes 35 false false R36.htm 9952184 - Disclosure - Regulatory Environment Sheet http://www.wecenergygroup.com/role/RegulatoryEnvironment Regulatory Environment Notes 36 false false R37.htm 9952185 - Disclosure - Other Income, Net Sheet http://www.wecenergygroup.com/role/OtherIncomeNet Other Income, Net Notes 37 false false R38.htm 9952186 - Disclosure - New Accounting Pronouncements Sheet http://www.wecenergygroup.com/role/NewAccountingPronouncements New Accounting Pronouncements Notes 38 false false R39.htm 9952187 - Disclosure - Schedule I - Condensed Parent Company Financial Statements Sheet http://www.wecenergygroup.com/role/ScheduleICondensedParentCompanyFinancialStatements Schedule I - Condensed Parent Company Financial Statements Notes 39 false false R40.htm 9952188 - Disclosure - Schedule II - Valuation and Qualifying Accounts Sheet http://www.wecenergygroup.com/role/ScheduleIIValuationandQualifyingAccounts Schedule II - Valuation and Qualifying Accounts Notes 40 false false R41.htm 995445 - Disclosure - Insider Trading Arrangements Sheet http://xbrl.sec.gov/ecd/role/InsiderTradingArrangements Insider Trading Arrangements Notes 41 false false R42.htm 995550 - Disclosure - Cybersecurity Risk Management and Strategy Disclosure Sheet http://xbrl.sec.gov/cyd/role/CybersecurityRiskManagementAndStrategyDisclosure Cybersecurity Risk Management and Strategy Disclosure Notes 42 false false R43.htm 9955511 - Disclosure - Summary of Significant Accounting Policies (Policies) Sheet http://www.wecenergygroup.com/role/SummaryofSignificantAccountingPoliciesPolicies Summary of Significant Accounting Policies (Policies) Policies http://www.wecenergygroup.com/role/SummaryofSignificantAccountingPolicies 43 false false R44.htm 9955512 - Disclosure - Summary of Significant Accounting Policies (Tables) Sheet http://www.wecenergygroup.com/role/SummaryofSignificantAccountingPoliciesTables Summary of Significant Accounting Policies (Tables) Tables http://www.wecenergygroup.com/role/SummaryofSignificantAccountingPolicies 44 false false R45.htm 9955513 - Disclosure - Acquisitions (Tables) Sheet http://www.wecenergygroup.com/role/AcquisitionsTables Acquisitions (Tables) Tables http://www.wecenergygroup.com/role/Acquisitions 45 false false R46.htm 9955514 - Disclosure - Operating Revenues (Tables) Sheet http://www.wecenergygroup.com/role/OperatingRevenuesTables Operating Revenues (Tables) Tables http://www.wecenergygroup.com/role/OperatingRevenues 46 false false R47.htm 9955515 - Disclosure - Credit Losses (Tables) Sheet http://www.wecenergygroup.com/role/CreditLossesTables Credit Losses (Tables) Tables http://www.wecenergygroup.com/role/CreditLosses 47 false false R48.htm 9955516 - Disclosure - Regulatory Assets and Liabilities (Tables) Sheet http://www.wecenergygroup.com/role/RegulatoryAssetsandLiabilitiesTables Regulatory Assets and Liabilities (Tables) Tables http://www.wecenergygroup.com/role/RegulatoryAssetsandLiabilities 48 false false R49.htm 9955517 - Disclosure - Property, Plant, and Equipment (Tables) Sheet http://www.wecenergygroup.com/role/PropertyPlantandEquipmentTables Property, Plant, and Equipment (Tables) Tables http://www.wecenergygroup.com/role/PropertyPlantandEquipment 49 false false R50.htm 9955518 - Disclosure - Jointly Owned Utility Facilities (Tables) Sheet http://www.wecenergygroup.com/role/JointlyOwnedUtilityFacilitiesTables Jointly Owned Utility Facilities (Tables) Tables http://www.wecenergygroup.com/role/JointlyOwnedUtilityFacilities 50 false false R51.htm 9955519 - Disclosure - Asset Retirement Obligations (Tables) Sheet http://www.wecenergygroup.com/role/AssetRetirementObligationsTables Asset Retirement Obligations (Tables) Tables http://www.wecenergygroup.com/role/AssetRetirementObligations 51 false false R52.htm 9955520 - Disclosure - Goodwill and Intangibles (Tables) Sheet http://www.wecenergygroup.com/role/GoodwillandIntangiblesTables Goodwill and Intangibles (Tables) Tables http://www.wecenergygroup.com/role/GoodwillandIntangibles 52 false false R53.htm 9955521 - Disclosure - Common Equity (Tables) Sheet http://www.wecenergygroup.com/role/CommonEquityTables Common Equity (Tables) Tables http://www.wecenergygroup.com/role/CommonEquity 53 false false R54.htm 9955522 - Disclosure - Preferred Stock (Tables) Sheet http://www.wecenergygroup.com/role/PreferredStockTables Preferred Stock (Tables) Tables http://www.wecenergygroup.com/role/PreferredStock 54 false false R55.htm 9955523 - Disclosure - Short-Term Debt and Lines of Credit (Tables) Sheet http://www.wecenergygroup.com/role/ShortTermDebtandLinesofCreditTables Short-Term Debt and Lines of Credit (Tables) Tables http://www.wecenergygroup.com/role/ShortTermDebtandLinesofCredit 55 false false R56.htm 9955524 - Disclosure - Long-Term Debt (Tables) Sheet http://www.wecenergygroup.com/role/LongTermDebtTables Long-Term Debt (Tables) Tables http://www.wecenergygroup.com/role/LongTermDebt 56 false false R57.htm 9955525 - Disclosure - Leases (Tables) Sheet http://www.wecenergygroup.com/role/LeasesTables Leases (Tables) Tables http://www.wecenergygroup.com/role/Leases 57 false false R58.htm 9955526 - Disclosure - Income Taxes (Tables) Sheet http://www.wecenergygroup.com/role/IncomeTaxesTables Income Taxes (Tables) Tables http://www.wecenergygroup.com/role/IncomeTaxes 58 false false R59.htm 9955527 - Disclosure - Fair Value Measurements (Tables) Sheet http://www.wecenergygroup.com/role/FairValueMeasurementsTables Fair Value Measurements (Tables) Tables http://www.wecenergygroup.com/role/FairValueMeasurements 59 false false R60.htm 9955528 - Disclosure - Derivative Instruments (Tables) Sheet http://www.wecenergygroup.com/role/DerivativeInstrumentsTables Derivative Instruments (Tables) Tables http://www.wecenergygroup.com/role/DerivativeInstruments 60 false false R61.htm 9955529 - Disclosure - Guarantees (Tables) Sheet http://www.wecenergygroup.com/role/GuaranteesTables Guarantees (Tables) Tables http://www.wecenergygroup.com/role/Guarantees 61 false false R62.htm 9955530 - Disclosure - Employee Benefits (Tables) Sheet http://www.wecenergygroup.com/role/EmployeeBenefitsTables Employee Benefits (Tables) Tables http://www.wecenergygroup.com/role/EmployeeBenefits 62 false false R63.htm 9955531 - Disclosure - Investment in Transmission Affiliates (Tables) Sheet http://www.wecenergygroup.com/role/InvestmentinTransmissionAffiliatesTables Investment in Transmission Affiliates (Tables) Tables http://www.wecenergygroup.com/role/InvestmentinTransmissionAffiliates 63 false false R64.htm 9955532 - Disclosure - Segment Information (Tables) Sheet http://www.wecenergygroup.com/role/SegmentInformationTables Segment Information (Tables) Tables http://www.wecenergygroup.com/role/SegmentInformation 64 false false R65.htm 9955533 - Disclosure - Variable Interest Entities (Tables) Sheet http://www.wecenergygroup.com/role/VariableInterestEntitiesTables Variable Interest Entities (Tables) Tables http://www.wecenergygroup.com/role/VariableInterestEntities 65 false false R66.htm 9955534 - Disclosure - Commitments and Contingencies (Tables) Sheet http://www.wecenergygroup.com/role/CommitmentsandContingenciesTables Commitments and Contingencies (Tables) Tables http://www.wecenergygroup.com/role/CommitmentsandContingencies 66 false false R67.htm 9955535 - Disclosure - Supplemental Cash Flow Information (Tables) Sheet http://www.wecenergygroup.com/role/SupplementalCashFlowInformationTables Supplemental Cash Flow Information (Tables) Tables http://www.wecenergygroup.com/role/SupplementalCashFlowInformation 67 false false R68.htm 9955536 - Disclosure - Regulatory Environment (Tables) Sheet http://www.wecenergygroup.com/role/RegulatoryEnvironmentTables Regulatory Environment (Tables) Tables http://www.wecenergygroup.com/role/RegulatoryEnvironment 68 false false R69.htm 9955537 - Disclosure - Other Income, Net (Tables) Sheet http://www.wecenergygroup.com/role/OtherIncomeNetTables Other Income, Net (Tables) Tables http://www.wecenergygroup.com/role/OtherIncomeNet 69 false false R70.htm 9955538 - Disclosure - Summary of Significant Accounting Policies Nature of Operations (Details) Sheet http://www.wecenergygroup.com/role/SummaryofSignificantAccountingPoliciesNatureofOperationsDetails Summary of Significant Accounting Policies Nature of Operations (Details) Details 70 false false R71.htm 9955539 - Disclosure - Summary of Significant Accounting Policies Cash and Cash Equivalents (Details) Sheet http://www.wecenergygroup.com/role/SummaryofSignificantAccountingPoliciesCashandCashEquivalentsDetails Summary of Significant Accounting Policies Cash and Cash Equivalents (Details) Details 71 false false R72.htm 9955540 - Disclosure - Summary of Significant Accounting Policies Operating Revenues (Details) Sheet http://www.wecenergygroup.com/role/SummaryofSignificantAccountingPoliciesOperatingRevenuesDetails Summary of Significant Accounting Policies Operating Revenues (Details) Details 72 false false R73.htm 9955541 - Disclosure - Summary of Significant Accounting Policies Materials, Supplies, and Inventories (Details) Sheet http://www.wecenergygroup.com/role/SummaryofSignificantAccountingPoliciesMaterialsSuppliesandInventoriesDetails Summary of Significant Accounting Policies Materials, Supplies, and Inventories (Details) Details 73 false false R74.htm 9955542 - Disclosure - Summary of Significant Accounting Policies Property, Plant, and Equipment (Details) Sheet http://www.wecenergygroup.com/role/SummaryofSignificantAccountingPoliciesPropertyPlantandEquipmentDetails Summary of Significant Accounting Policies Property, Plant, and Equipment (Details) Details 74 false false R75.htm 9955543 - Disclosure - Summary of Significant Accounting Policies AFUDC (Details) Sheet http://www.wecenergygroup.com/role/SummaryofSignificantAccountingPoliciesAFUDCDetails Summary of Significant Accounting Policies AFUDC (Details) Details http://www.wecenergygroup.com/role/SummaryofSignificantAccountingPoliciesTables 75 false false R76.htm 9955544 - Disclosure - Summary of Significant Accounting Policies Cloud Computing Hosting Arrangements that are Service Contracts (Details) Sheet http://www.wecenergygroup.com/role/SummaryofSignificantAccountingPoliciesCloudComputingHostingArrangementsthatareServiceContractsDetails Summary of Significant Accounting Policies Cloud Computing Hosting Arrangements that are Service Contracts (Details) Details 76 false false R77.htm 9955545 - Disclosure - Summary of Significant Accounting Policies Asset Impairment (Details) Sheet http://www.wecenergygroup.com/role/SummaryofSignificantAccountingPoliciesAssetImpairmentDetails Summary of Significant Accounting Policies Asset Impairment (Details) Details 77 false false R78.htm 9955546 - Disclosure - Summary of Significant Accounting Policies Stock-Based Compensation (Details) Sheet http://www.wecenergygroup.com/role/SummaryofSignificantAccountingPoliciesStockBasedCompensationDetails Summary of Significant Accounting Policies Stock-Based Compensation (Details) Details 78 false false R79.htm 9955547 - Disclosure - Summary of Significant Accounting Policies Earnings Per Share (Details) Sheet http://www.wecenergygroup.com/role/SummaryofSignificantAccountingPoliciesEarningsPerShareDetails Summary of Significant Accounting Policies Earnings Per Share (Details) Details 79 false false R80.htm 9955548 - Disclosure - Summary of Significant Accounting Policies - Leases (Details) Sheet http://www.wecenergygroup.com/role/SummaryofSignificantAccountingPoliciesLeasesDetails Summary of Significant Accounting Policies - Leases (Details) Details http://www.wecenergygroup.com/role/SummaryofSignificantAccountingPoliciesTables 80 false false R81.htm 9955549 - Disclosure - Summary of Significant Accounting Policies Customer Concentrations of Credit Risk (Details) Sheet http://www.wecenergygroup.com/role/SummaryofSignificantAccountingPoliciesCustomerConcentrationsofCreditRiskDetails Summary of Significant Accounting Policies Customer Concentrations of Credit Risk (Details) Details 81 false false R82.htm 9955550 - Disclosure - Acquisitions - Hardin III (Details) Sheet http://www.wecenergygroup.com/role/AcquisitionsHardinIIIDetails Acquisitions - Hardin III (Details) Details 82 false false R83.htm 9955551 - Disclosure - Acquisitions - Delilah (Details) Sheet http://www.wecenergygroup.com/role/AcquisitionsDelilahDetails Acquisitions - Delilah (Details) Details 83 false false R84.htm 9955552 - Disclosure - Acquisitions - Samson I (Details) Sheet http://www.wecenergygroup.com/role/AcquisitionsSamsonIDetails Acquisitions - Samson I (Details) Details 84 false false R85.htm 9955553 - Disclosure - Acquisitions - Maple Flats (Details) Sheet http://www.wecenergygroup.com/role/AcquisitionsMapleFlatsDetails Acquisitions - Maple Flats (Details) Details 85 false false R86.htm 9955554 - Disclosure - Acquisitions - Sapphire Sky (Details) Sheet http://www.wecenergygroup.com/role/AcquisitionsSapphireSkyDetails Acquisitions - Sapphire Sky (Details) Details 86 false false R87.htm 9955555 - Disclosure - Acquisitions - Whitetail (Details) Sheet http://www.wecenergygroup.com/role/AcquisitionsWhitetailDetails Acquisitions - Whitetail (Details) Details 87 false false R88.htm 9955556 - Disclosure - Acquisitions - West Riverside (Details) Sheet http://www.wecenergygroup.com/role/AcquisitionsWestRiversideDetails Acquisitions - West Riverside (Details) Details 88 false false R89.htm 9955557 - Disclosure - Acquisitions - Red Barn (Details) Sheet http://www.wecenergygroup.com/role/AcquisitionsRedBarnDetails Acquisitions - Red Barn (Details) Details 89 false false R90.htm 9955558 - Disclosure - Acquisitions - Whitewater (Details) Sheet http://www.wecenergygroup.com/role/AcquisitionsWhitewaterDetails Acquisitions - Whitewater (Details) Details 90 false false R91.htm 9955559 - Disclosure - Dispositions - WE (Details) Sheet http://www.wecenergygroup.com/role/DispositionsWEDetails Dispositions - WE (Details) Details 91 false false R92.htm 9955560 - Disclosure - Operating Revenues - Disaggregation Of Operating Revenues by Segment (Details) Sheet http://www.wecenergygroup.com/role/OperatingRevenuesDisaggregationOfOperatingRevenuesbySegmentDetails Operating Revenues - Disaggregation Of Operating Revenues by Segment (Details) Details 92 false false R93.htm 9955561 - Disclosure - Operating Revenues - Disaggregation of Electric Utility Operating Revenues by Customer Class (Details) Sheet http://www.wecenergygroup.com/role/OperatingRevenuesDisaggregationofElectricUtilityOperatingRevenuesbyCustomerClassDetails Operating Revenues - Disaggregation of Electric Utility Operating Revenues by Customer Class (Details) Details 93 false false R94.htm 9955562 - Disclosure - Operating Revenues - Disaggregation of Natural Gas Utility Operating Revenues by Customer Class (Details) Sheet http://www.wecenergygroup.com/role/OperatingRevenuesDisaggregationofNaturalGasUtilityOperatingRevenuesbyCustomerClassDetails Operating Revenues - Disaggregation of Natural Gas Utility Operating Revenues by Customer Class (Details) Details 94 false false R95.htm 9955563 - Disclosure - Operating Revenues - Other Non-Utility Operating Revenues (Details) Sheet http://www.wecenergygroup.com/role/OperatingRevenuesOtherNonUtilityOperatingRevenuesDetails Operating Revenues - Other Non-Utility Operating Revenues (Details) Details 95 false false R96.htm 9955564 - Disclosure - Operating Revenues - Other Operating Revenues (Details) Sheet http://www.wecenergygroup.com/role/OperatingRevenuesOtherOperatingRevenuesDetails Operating Revenues - Other Operating Revenues (Details) Details 96 false false R97.htm 9955565 - Disclosure - Credit Losses - Gross Receivables and Related Allowances (Details) Sheet http://www.wecenergygroup.com/role/CreditLossesGrossReceivablesandRelatedAllowancesDetails Credit Losses - Gross Receivables and Related Allowances (Details) Details 97 false false R98.htm 9955566 - Disclosure - Credit Losses - Rollforward of Allowances (Details) Sheet http://www.wecenergygroup.com/role/CreditLossesRollforwardofAllowancesDetails Credit Losses - Rollforward of Allowances (Details) Details 98 false false R99.htm 9955567 - Disclosure - Regulatory Assets and Liabilities - Regulatory Assets (Details) Sheet http://www.wecenergygroup.com/role/RegulatoryAssetsandLiabilitiesRegulatoryAssetsDetails Regulatory Assets and Liabilities - Regulatory Assets (Details) Details 99 false false R100.htm 9955568 - Disclosure - Regulatory Assets and Liabilities - Regulatory Liabilities (Details) Sheet http://www.wecenergygroup.com/role/RegulatoryAssetsandLiabilitiesRegulatoryLiabilitiesDetails Regulatory Assets and Liabilities - Regulatory Liabilities (Details) Details 100 false false R101.htm 9955569 - Disclosure - Regulatory Assets and Liabilities - Oak Creek Power Plant Units 5-6 (Details) Sheet http://www.wecenergygroup.com/role/RegulatoryAssetsandLiabilitiesOakCreekPowerPlantUnits56Details Regulatory Assets and Liabilities - Oak Creek Power Plant Units 5-6 (Details) Details 101 false false R102.htm 9955570 - Disclosure - Property, Plant, and Equipment - Balances (Details) Sheet http://www.wecenergygroup.com/role/PropertyPlantandEquipmentBalancesDetails Property, Plant, and Equipment - Balances (Details) Details 102 false false R103.htm 9955571 - Disclosure - Property, Plant, and Equipment - Severance Liability (Details) Sheet http://www.wecenergygroup.com/role/PropertyPlantandEquipmentSeveranceLiabilityDetails Property, Plant, and Equipment - Severance Liability (Details) Details 103 false false R104.htm 9955572 - Disclosure - Property, Plant, and Equipment - Oak Creek Power Plant Units 7 and 8 (Details) Sheet http://www.wecenergygroup.com/role/PropertyPlantandEquipmentOakCreekPowerPlantUnits7and8Details Property, Plant, and Equipment - Oak Creek Power Plant Units 7 and 8 (Details) Details 104 false false R105.htm 9955573 - Disclosure - Property, Plant, and Equipment - Columbia Energy Center Units 1 and 2 (Details) Sheet http://www.wecenergygroup.com/role/PropertyPlantandEquipmentColumbiaEnergyCenterUnits1and2Details Property, Plant, and Equipment - Columbia Energy Center Units 1 and 2 (Details) Details 105 false false R106.htm 9955574 - Disclosure - Property, Plant, and Equipment - Samson and Delilah Storm Damage (Details) Sheet http://www.wecenergygroup.com/role/PropertyPlantandEquipmentSamsonandDelilahStormDamageDetails Property, Plant, and Equipment - Samson and Delilah Storm Damage (Details) Details 106 false false R107.htm 9955575 - Disclosure - Property, Plant, and Equipment - PGL and NSG Impairment (Details) Sheet http://www.wecenergygroup.com/role/PropertyPlantandEquipmentPGLandNSGImpairmentDetails Property, Plant, and Equipment - PGL and NSG Impairment (Details) Details 107 false false R108.htm 9955576 - Disclosure - Jointly Owned Utility Facilities In-service (Details) Sheet http://www.wecenergygroup.com/role/JointlyOwnedUtilityFacilitiesInserviceDetails Jointly Owned Utility Facilities In-service (Details) Details 108 false false R109.htm 9955577 - Disclosure - Jointly Owned Utility Facilities Approved by PSCW (Details) Sheet http://www.wecenergygroup.com/role/JointlyOwnedUtilityFacilitiesApprovedbyPSCWDetails Jointly Owned Utility Facilities Approved by PSCW (Details) Details 109 false false R110.htm 9955578 - Disclosure - Asset Retirement Obligations (Details) Sheet http://www.wecenergygroup.com/role/AssetRetirementObligationsDetails Asset Retirement Obligations (Details) Details http://www.wecenergygroup.com/role/AssetRetirementObligationsTables 110 false false R111.htm 9955579 - Disclosure - Goodwill and Intangibles - Goodwill (Details) Sheet http://www.wecenergygroup.com/role/GoodwillandIntangiblesGoodwillDetails Goodwill and Intangibles - Goodwill (Details) Details 111 false false R112.htm 9955580 - Disclosure - Goodwill and Intangibles - Indefinite Lived Intangible Assets (Details) Sheet http://www.wecenergygroup.com/role/GoodwillandIntangiblesIndefiniteLivedIntangibleAssetsDetails Goodwill and Intangibles - Indefinite Lived Intangible Assets (Details) Details 112 false false R113.htm 9955581 - Disclosure - Goodwill and Intangibles - Finite-lived Intangible Asset (Details) Sheet http://www.wecenergygroup.com/role/GoodwillandIntangiblesFinitelivedIntangibleAssetDetails Goodwill and Intangibles - Finite-lived Intangible Asset (Details) Details 113 false false R114.htm 9955582 - Disclosure - Goodwill and Intangibles - Intangible Liabilities (Details) Sheet http://www.wecenergygroup.com/role/GoodwillandIntangiblesIntangibleLiabilitiesDetails Goodwill and Intangibles - Intangible Liabilities (Details) Details 114 false false R115.htm 9955583 - Disclosure - Common Equity - Stock-Based Compensation Expense (Details) Sheet http://www.wecenergygroup.com/role/CommonEquityStockBasedCompensationExpenseDetails Common Equity - Stock-Based Compensation Expense (Details) Details 115 false false R116.htm 9955584 - Disclosure - Common Equity - Stock Options (Details) Sheet http://www.wecenergygroup.com/role/CommonEquityStockOptionsDetails Common Equity - Stock Options (Details) Details 116 false false R117.htm 9955585 - Disclosure - Common Equity - Restricted Shares (Details) Sheet http://www.wecenergygroup.com/role/CommonEquityRestrictedSharesDetails Common Equity - Restricted Shares (Details) Details 117 false false R118.htm 9955586 - Disclosure - Common Equity - Performance Units (Details) Sheet http://www.wecenergygroup.com/role/CommonEquityPerformanceUnitsDetails Common Equity - Performance Units (Details) Details 118 false false R119.htm 9955587 - Disclosure - Common Equity - Dividend Restrictions (Details) Sheet http://www.wecenergygroup.com/role/CommonEquityDividendRestrictionsDetails Common Equity - Dividend Restrictions (Details) Details 119 false false R120.htm 9955588 - Disclosure - Common Equity - Common Stock - ATM Program (Details) Sheet http://www.wecenergygroup.com/role/CommonEquityCommonStockATMProgramDetails Common Equity - Common Stock - ATM Program (Details) Details 120 false false R121.htm 9955589 - Disclosure - Common Equity - Common Stock Issued and Purchased (Details) Sheet http://www.wecenergygroup.com/role/CommonEquityCommonStockIssuedandPurchasedDetails Common Equity - Common Stock Issued and Purchased (Details) Details 121 false false R122.htm 9955590 - Disclosure - Common Equity - Common Stock Dividends (Details) Sheet http://www.wecenergygroup.com/role/CommonEquityCommonStockDividendsDetails Common Equity - Common Stock Dividends (Details) Details 122 false false R123.htm 9955591 - Disclosure - Common Equity - EPS (Details) Sheet http://www.wecenergygroup.com/role/CommonEquityEPSDetails Common Equity - EPS (Details) Details 123 false false R124.htm 9955592 - Disclosure - Preferred Stock (Details) Sheet http://www.wecenergygroup.com/role/PreferredStockDetails Preferred Stock (Details) Details http://www.wecenergygroup.com/role/PreferredStockTables 124 false false R125.htm 9955593 - Disclosure - Short-Term Debt and Lines of Credit - Outstanding Amounts (Details) Sheet http://www.wecenergygroup.com/role/ShortTermDebtandLinesofCreditOutstandingAmountsDetails Short-Term Debt and Lines of Credit - Outstanding Amounts (Details) Details 125 false false R126.htm 9955594 - Disclosure - Short-Term Debt and Lines of Credit - Credit Facilities (Details) Sheet http://www.wecenergygroup.com/role/ShortTermDebtandLinesofCreditCreditFacilitiesDetails Short-Term Debt and Lines of Credit - Credit Facilities (Details) Details 126 false false R127.htm 9955595 - Disclosure - Long-Term Debt - Debt Outstanding (Details) Sheet http://www.wecenergygroup.com/role/LongTermDebtDebtOutstandingDetails Long-Term Debt - Debt Outstanding (Details) Details 127 false false R128.htm 9955596 - Disclosure - Long-Term Debt - Issuances and Redemptions (Details) Sheet http://www.wecenergygroup.com/role/LongTermDebtIssuancesandRedemptionsDetails Long-Term Debt - Issuances and Redemptions (Details) Details 128 false false R129.htm 9955597 - Disclosure - Long-Term Debt - Convertible Debt (Details) Sheet http://www.wecenergygroup.com/role/LongTermDebtConvertibleDebtDetails Long-Term Debt - Convertible Debt (Details) Details 129 false false R130.htm 9955598 - Disclosure - Long-Term Debt - Maturities of Long-Term Debt (Details) Sheet http://www.wecenergygroup.com/role/LongTermDebtMaturitiesofLongTermDebtDetails Long-Term Debt - Maturities of Long-Term Debt (Details) Details 130 false false R131.htm 9955599 - Disclosure - Leases - Land Leases - Utility Solar Generation (Details) Sheet http://www.wecenergygroup.com/role/LeasesLandLeasesUtilitySolarGenerationDetails Leases - Land Leases - Utility Solar Generation (Details) Details 131 false false R132.htm 9955600 - Disclosure - Leases - Land Leases -Non-Utility Energy Infrastructure Solar Generation (Details) Sheet http://www.wecenergygroup.com/role/LeasesLandLeasesNonUtilityEnergyInfrastructureSolarGenerationDetails Leases - Land Leases -Non-Utility Energy Infrastructure Solar Generation (Details) Details 132 false false R133.htm 9955601 - Disclosure - Leases - Lease Expense and Supplemental Cash Flow Information (Details) Sheet http://www.wecenergygroup.com/role/LeasesLeaseExpenseandSupplementalCashFlowInformationDetails Leases - Lease Expense and Supplemental Cash Flow Information (Details) Details 133 false false R134.htm 9955602 - Disclosure - Leases - Finance and Operating Lease Right of Use Assets and Obligations (Details) Sheet http://www.wecenergygroup.com/role/LeasesFinanceandOperatingLeaseRightofUseAssetsandObligationsDetails Leases - Finance and Operating Lease Right of Use Assets and Obligations (Details) Details 134 false false R135.htm 9955603 - Disclosure - Leases - Future Minimum Lease Payments (Details) Sheet http://www.wecenergygroup.com/role/LeasesFutureMinimumLeasePaymentsDetails Leases - Future Minimum Lease Payments (Details) Details 135 false false R136.htm 9955604 - Disclosure - Income Taxes - Summary of Income Tax Expense (Details) Sheet http://www.wecenergygroup.com/role/IncomeTaxesSummaryofIncomeTaxExpenseDetails Income Taxes - Summary of Income Tax Expense (Details) Details 136 false false R137.htm 9955605 - Disclosure - Income Taxes - Statutory Rate Reconciliation (Details) Sheet http://www.wecenergygroup.com/role/IncomeTaxesStatutoryRateReconciliationDetails Income Taxes - Statutory Rate Reconciliation (Details) Details 137 false false R138.htm 9955606 - Disclosure - Income Taxes - Components of Deferred Income Taxes (Details) Sheet http://www.wecenergygroup.com/role/IncomeTaxesComponentsofDeferredIncomeTaxesDetails Income Taxes - Components of Deferred Income Taxes (Details) Details 138 false false R139.htm 9955607 - Disclosure - Income Taxes - Carryforwards (Details) Sheet http://www.wecenergygroup.com/role/IncomeTaxesCarryforwardsDetails Income Taxes - Carryforwards (Details) Details 139 false false R140.htm 9955608 - Disclosure - Income Taxes - Schedule of Unrecognized Tax Benefits Roll Forward (Details) Sheet http://www.wecenergygroup.com/role/IncomeTaxesScheduleofUnrecognizedTaxBenefitsRollForwardDetails Income Taxes - Schedule of Unrecognized Tax Benefits Roll Forward (Details) Details 140 false false R141.htm 9955609 - Disclosure - Income Taxes - Roll forward of interest accrued on unrecognized tax benefits (Details) Sheet http://www.wecenergygroup.com/role/IncomeTaxesRollforwardofinterestaccruedonunrecognizedtaxbenefitsDetails Income Taxes - Roll forward of interest accrued on unrecognized tax benefits (Details) Details 141 false false R142.htm 9955610 - Disclosure - Income Taxes - Cash Paid (Received) for Income Taxes, Net (Details) Sheet http://www.wecenergygroup.com/role/IncomeTaxesCashPaidReceivedforIncomeTaxesNetDetails Income Taxes - Cash Paid (Received) for Income Taxes, Net (Details) Details 142 false false R143.htm 9955611 - Disclosure - Fair Value Measurements - Assets and Liabilities Measured on a Recurring Basis (Details) Sheet http://www.wecenergygroup.com/role/FairValueMeasurementsAssetsandLiabilitiesMeasuredonaRecurringBasisDetails Fair Value Measurements - Assets and Liabilities Measured on a Recurring Basis (Details) Details 143 false false R144.htm 9955612 - Disclosure - Fair Value Measurements - Net Unrealized Gains (Losses) on Investments Still Held (Details) Sheet http://www.wecenergygroup.com/role/FairValueMeasurementsNetUnrealizedGainsLossesonInvestmentsStillHeldDetails Fair Value Measurements - Net Unrealized Gains (Losses) on Investments Still Held (Details) Details 144 false false R145.htm 9955613 - Disclosure - Fair Value Measurements - Level 3 Reconciliation (Details) Sheet http://www.wecenergygroup.com/role/FairValueMeasurementsLevel3ReconciliationDetails Fair Value Measurements - Level 3 Reconciliation (Details) Details 145 false false R146.htm 9955614 - Disclosure - Fair Value Measurements - Financial Instruments (Details) Sheet http://www.wecenergygroup.com/role/FairValueMeasurementsFinancialInstrumentsDetails Fair Value Measurements - Financial Instruments (Details) Details 146 false false R147.htm 9955615 - Disclosure - Derivative Instruments - Derivative Assets and Liabilities (Details) Sheet http://www.wecenergygroup.com/role/DerivativeInstrumentsDerivativeAssetsandLiabilitiesDetails Derivative Instruments - Derivative Assets and Liabilities (Details) Details 147 false false R148.htm 9955616 - Disclosure - Derivative Instruments - Gains (Losses) and Notional Volumes (Details) Sheet http://www.wecenergygroup.com/role/DerivativeInstrumentsGainsLossesandNotionalVolumesDetails Derivative Instruments - Gains (Losses) and Notional Volumes (Details) Details 148 false false R149.htm 9955617 - Disclosure - Derivative Instruments - Balance Sheet Offsetting (Details) Sheet http://www.wecenergygroup.com/role/DerivativeInstrumentsBalanceSheetOffsettingDetails Derivative Instruments - Balance Sheet Offsetting (Details) Details 149 false false R150.htm 9955618 - Disclosure - Guarantees (Details) Sheet http://www.wecenergygroup.com/role/GuaranteesDetails Guarantees (Details) Details http://www.wecenergygroup.com/role/GuaranteesTables 150 false false R151.htm 9955619 - Disclosure - Employee Benefits - Change in Benefit Obligations and Plan Assets (Details) Sheet http://www.wecenergygroup.com/role/EmployeeBenefitsChangeinBenefitObligationsandPlanAssetsDetails Employee Benefits - Change in Benefit Obligations and Plan Assets (Details) Details 151 false false R152.htm 9955620 - Disclosure - Employee Benefits - Amounts Recognized on the Balance Sheets (Details) Sheet http://www.wecenergygroup.com/role/EmployeeBenefitsAmountsRecognizedontheBalanceSheetsDetails Employee Benefits - Amounts Recognized on the Balance Sheets (Details) Details 152 false false R153.htm 9955621 - Disclosure - Employee Benefits - Accumulated Benefit Obligations (Details) Sheet http://www.wecenergygroup.com/role/EmployeeBenefitsAccumulatedBenefitObligationsDetails Employee Benefits - Accumulated Benefit Obligations (Details) Details 153 false false R154.htm 9955622 - Disclosure - Employee Benefits - Amounts Not Yet Recognized in Net Periodic Benefit Cost (Details) Sheet http://www.wecenergygroup.com/role/EmployeeBenefitsAmountsNotYetRecognizedinNetPeriodicBenefitCostDetails Employee Benefits - Amounts Not Yet Recognized in Net Periodic Benefit Cost (Details) Details 154 false false R155.htm 9955623 - Disclosure - Employee Benefits - Net Periodic Benefit Cost (Credit) (Detail) Sheet http://www.wecenergygroup.com/role/EmployeeBenefitsNetPeriodicBenefitCostCreditDetail Employee Benefits - Net Periodic Benefit Cost (Credit) (Detail) Details 155 false false R156.htm 9955624 - Disclosure - Employee Benefits - Assumptions (Details) Sheet http://www.wecenergygroup.com/role/EmployeeBenefitsAssumptionsDetails Employee Benefits - Assumptions (Details) Details 156 false false R157.htm 9955625 - Disclosure - Employee Benefits - Target Asset Allocations (Details) Sheet http://www.wecenergygroup.com/role/EmployeeBenefitsTargetAssetAllocationsDetails Employee Benefits - Target Asset Allocations (Details) Details 157 false false R158.htm 9955626 - Disclosure - Employee Benefits - Plan Assets (Details) Sheet http://www.wecenergygroup.com/role/EmployeeBenefitsPlanAssetsDetails Employee Benefits - Plan Assets (Details) Details 158 false false R159.htm 9955627 - Disclosure - Employee Benefits - Reconciliation of Level 3 plan assets (Details) Sheet http://www.wecenergygroup.com/role/EmployeeBenefitsReconciliationofLevel3planassetsDetails Employee Benefits - Reconciliation of Level 3 plan assets (Details) Details 159 false false R160.htm 9955628 - Disclosure - Employee Benefits - Cash Flows (Details) Sheet http://www.wecenergygroup.com/role/EmployeeBenefitsCashFlowsDetails Employee Benefits - Cash Flows (Details) Details 160 false false R161.htm 9955629 - Disclosure - Employee Benefits - Defined Contribution Benefit Plans (Details) Sheet http://www.wecenergygroup.com/role/EmployeeBenefitsDefinedContributionBenefitPlansDetails Employee Benefits - Defined Contribution Benefit Plans (Details) Details 161 false false R162.htm 9955630 - Disclosure - Investment in Transmission Affiliates - Changes to Investment (Details) Sheet http://www.wecenergygroup.com/role/InvestmentinTransmissionAffiliatesChangestoInvestmentDetails Investment in Transmission Affiliates - Changes to Investment (Details) Details 162 false false R163.htm 9955631 - Disclosure - Investment in Transmission Affiliates - ATC Return on Equity (Details) Sheet http://www.wecenergygroup.com/role/InvestmentinTransmissionAffiliatesATCReturnonEquityDetails Investment in Transmission Affiliates - ATC Return on Equity (Details) Details 163 false false R164.htm 9955632 - Disclosure - Investment in Transmission Affiliates - Related Party Transactions (Details) Sheet http://www.wecenergygroup.com/role/InvestmentinTransmissionAffiliatesRelatedPartyTransactionsDetails Investment in Transmission Affiliates - Related Party Transactions (Details) Details 164 false false R165.htm 9955633 - Disclosure - Investment in Transmission Affiliates - Receivables and Payables (Details) Sheet http://www.wecenergygroup.com/role/InvestmentinTransmissionAffiliatesReceivablesandPayablesDetails Investment in Transmission Affiliates - Receivables and Payables (Details) Details 165 false false R166.htm 9955634 - Disclosure - Investment in Transmission Affiliates - ATC Summarized Financial Data (Details) Sheet http://www.wecenergygroup.com/role/InvestmentinTransmissionAffiliatesATCSummarizedFinancialDataDetails Investment in Transmission Affiliates - ATC Summarized Financial Data (Details) Details 166 false false R167.htm 9955635 - Disclosure - Segment Information (Details) Sheet http://www.wecenergygroup.com/role/SegmentInformationDetails Segment Information (Details) Details http://www.wecenergygroup.com/role/SegmentInformationTables 167 false false R168.htm 9955636 - Disclosure - Variable Interest Entities - WEPCo Environmental Trust (Details) Sheet http://www.wecenergygroup.com/role/VariableInterestEntitiesWEPCoEnvironmentalTrustDetails Variable Interest Entities - WEPCo Environmental Trust (Details) Details 168 false false R169.htm 9955637 - Disclosure - Variable Interest Entities - Investment in Transmission Affiliates (Details) Sheet http://www.wecenergygroup.com/role/VariableInterestEntitiesInvestmentinTransmissionAffiliatesDetails Variable Interest Entities - Investment in Transmission Affiliates (Details) Details 169 false false R170.htm 9955638 - Disclosure - Commitments and Contingencies - Unconditional Purchase Obligations (Details) Sheet http://www.wecenergygroup.com/role/CommitmentsandContingenciesUnconditionalPurchaseObligationsDetails Commitments and Contingencies - Unconditional Purchase Obligations (Details) Details 170 false false R171.htm 9955639 - Disclosure - Commitments and Contingencies - Environmental Matters (Details) Sheet http://www.wecenergygroup.com/role/CommitmentsandContingenciesEnvironmentalMattersDetails Commitments and Contingencies - Environmental Matters (Details) Details 171 false false R172.htm 9955640 - Disclosure - Supplemental Cash Flow Information - Supplemental Information (Details) Sheet http://www.wecenergygroup.com/role/SupplementalCashFlowInformationSupplementalInformationDetails Supplemental Cash Flow Information - Supplemental Information (Details) Details 172 false false R173.htm 9955641 - Disclosure - Supplemental Cash Flow Information - Reconciliation of Cash, Cash Equivalents, and Restricted Cash (Details) Sheet http://www.wecenergygroup.com/role/SupplementalCashFlowInformationReconciliationofCashCashEquivalentsandRestrictedCashDetails Supplemental Cash Flow Information - Reconciliation of Cash, Cash Equivalents, and Restricted Cash (Details) Details 173 false false R174.htm 9955642 - Disclosure - Regulatory Environment - WI VLC and Bespoke Resources Tariffs (Details) Sheet http://www.wecenergygroup.com/role/RegulatoryEnvironmentWIVLCandBespokeResourcesTariffsDetails Regulatory Environment - WI VLC and Bespoke Resources Tariffs (Details) Details 174 false false R175.htm 9955643 - Disclosure - Regulatory Environment - WI 2025 and 2026 Rates (Details) Sheet http://www.wecenergygroup.com/role/RegulatoryEnvironmentWI2025and2026RatesDetails Regulatory Environment - WI 2025 and 2026 Rates (Details) Details 175 false false R176.htm 9955644 - Disclosure - Regulatory Environment - WI 2024 Limited Rate Case Re-Opener (Details) Sheet http://www.wecenergygroup.com/role/RegulatoryEnvironmentWI2024LimitedRateCaseReOpenerDetails Regulatory Environment - WI 2024 Limited Rate Case Re-Opener (Details) Details 176 false false R177.htm 9955645 - Disclosure - Regulatory Environment - WI 2023 and 2024 Rates (Details) Sheet http://www.wecenergygroup.com/role/RegulatoryEnvironmentWI2023and2024RatesDetails Regulatory Environment - WI 2023 and 2024 Rates (Details) Details 177 false false R178.htm 9955646 - Disclosure - Regulatory Environment - PGL and NSG 2026 Rate Application (Details) Sheet http://www.wecenergygroup.com/role/RegulatoryEnvironmentPGLandNSG2026RateApplicationDetails Regulatory Environment - PGL and NSG 2026 Rate Application (Details) Details 178 false false R179.htm 9955647 - Disclosure - Regulatory Environment - PGL and NSG 2023 Rate Order (Details) Sheet http://www.wecenergygroup.com/role/RegulatoryEnvironmentPGLandNSG2023RateOrderDetails Regulatory Environment - PGL and NSG 2023 Rate Order (Details) Details 179 false false R180.htm 9955648 - Disclosure - Regulatory Environment - PGL and NSG UEA Rider (Details) Sheet http://www.wecenergygroup.com/role/RegulatoryEnvironmentPGLandNSGUEARiderDetails Regulatory Environment - PGL and NSG UEA Rider (Details) Details 180 false false R181.htm 9955649 - Disclosure - Regulatory Environment - PGL QIP Rider (Details) Sheet http://www.wecenergygroup.com/role/RegulatoryEnvironmentPGLQIPRiderDetails Regulatory Environment - PGL QIP Rider (Details) Details 181 false false R182.htm 9955650 - Disclosure - Regulatory Environment - PGL and NSG QIP and UEA Proposed Settlement (Details) Sheet http://www.wecenergygroup.com/role/RegulatoryEnvironmentPGLandNSGQIPandUEAProposedSettlementDetails Regulatory Environment - PGL and NSG QIP and UEA Proposed Settlement (Details) Details 182 false false R183.htm 9955651 - Disclosure - Regulatory Environment - MERC 2023 Rate Order (Details) Sheet http://www.wecenergygroup.com/role/RegulatoryEnvironmentMERC2023RateOrderDetails Regulatory Environment - MERC 2023 Rate Order (Details) Details 183 false false R184.htm 9955652 - Disclosure - Regulatory Environment - MGU 2024 Rate Order (Details) Sheet http://www.wecenergygroup.com/role/RegulatoryEnvironmentMGU2024RateOrderDetails Regulatory Environment - MGU 2024 Rate Order (Details) Details 184 false false R185.htm 9955653 - Disclosure - Regulatory Environment - MGU 2023 Rate Order (Details) Sheet http://www.wecenergygroup.com/role/RegulatoryEnvironmentMGU2023RateOrderDetails Regulatory Environment - MGU 2023 Rate Order (Details) Details 185 false false R186.htm 9955654 - Disclosure - Regulatory Environment - UMERC AREP (Details) Sheet http://www.wecenergygroup.com/role/RegulatoryEnvironmentUMERCAREPDetails Regulatory Environment - UMERC AREP (Details) Details 186 false false R187.htm 9955655 - Disclosure - Regulatory Environment - UMERC 2024 Rate Order (Details) Sheet http://www.wecenergygroup.com/role/RegulatoryEnvironmentUMERC2024RateOrderDetails Regulatory Environment - UMERC 2024 Rate Order (Details) Details 187 false false R188.htm 9955656 - Disclosure - Other Income, Net (Details) Sheet http://www.wecenergygroup.com/role/OtherIncomeNetDetails Other Income, Net (Details) Details http://www.wecenergygroup.com/role/OtherIncomeNetTables 188 false false R189.htm 9955657 - Disclosure - Schedule I - Income Statements (Details) Sheet http://www.wecenergygroup.com/role/ScheduleIIncomeStatementsDetails Schedule I - Income Statements (Details) Details 189 false false R190.htm 9955658 - Disclosure - Schedule I - Statements of Comprehensive Income (Details) Sheet http://www.wecenergygroup.com/role/ScheduleIStatementsofComprehensiveIncomeDetails Schedule I - Statements of Comprehensive Income (Details) Details 190 false false R191.htm 9955659 - Disclosure - Schedule I - Balance Sheets (Details) Sheet http://www.wecenergygroup.com/role/ScheduleIBalanceSheetsDetails Schedule I - Balance Sheets (Details) Details 191 false false R192.htm 9955660 - Disclosure - Schedule I - Statements of Cash Flows (Details) Sheet http://www.wecenergygroup.com/role/ScheduleIStatementsofCashFlowsDetails Schedule I - Statements of Cash Flows (Details) Details 192 false false R193.htm 9955661 - Disclosure - Schedule I - Cash Dividends Received from Subsidiaries (Details) Sheet http://www.wecenergygroup.com/role/ScheduleICashDividendsReceivedfromSubsidiariesDetails Schedule I - Cash Dividends Received from Subsidiaries (Details) Details 193 false false R194.htm 9955662 - Disclosure - Schedule I - Long-Term Debt (Details) Sheet http://www.wecenergygroup.com/role/ScheduleILongTermDebtDetails Schedule I - Long-Term Debt (Details) Details 194 false false R195.htm 9955663 - Disclosure - Schedule I - Fair Value Measurements (Details) Sheet http://www.wecenergygroup.com/role/ScheduleIFairValueMeasurementsDetails Schedule I - Fair Value Measurements (Details) Details 195 false false R196.htm 9955664 - Disclosure - Schedule 1 - Guarantees (Details) Sheet http://www.wecenergygroup.com/role/Schedule1GuaranteesDetails Schedule 1 - Guarantees (Details) Details 196 false false R197.htm 9955665 - Disclosure - Schedule I - Supplemental Cash Flow Information (Details) Sheet http://www.wecenergygroup.com/role/ScheduleISupplementalCashFlowInformationDetails Schedule I - Supplemental Cash Flow Information (Details) Details 197 false false R198.htm 9955666 - Disclosure - Schedule I - Short-Term Notes Receivable from Related Parties (Details) Notes http://www.wecenergygroup.com/role/ScheduleIShortTermNotesReceivablefromRelatedPartiesDetails Schedule I - Short-Term Notes Receivable from Related Parties (Details) Details 198 false false R199.htm 9955667 - Disclosure - Schedule I - Short-Term Notes Payable to Related Parties (Details) Notes http://www.wecenergygroup.com/role/ScheduleIShortTermNotesPayabletoRelatedPartiesDetails Schedule I - Short-Term Notes Payable to Related Parties (Details) Details 199 false false R200.htm 9955668 - Disclosure - Schedule II - Valuation and Qualifying Accounts (Details) Sheet http://www.wecenergygroup.com/role/ScheduleIIValuationandQualifyingAccountsDetails Schedule II - Valuation and Qualifying Accounts (Details) Details http://www.wecenergygroup.com/role/ScheduleIIValuationandQualifyingAccounts 200 false false All Reports Book All Reports wec-20251231.htm wec-20251231.xsd wec-20251231_cal.xml wec-20251231_def.xml wec-20251231_lab.xml wec-20251231_pre.xml wec-20251231_g1.jpg http://fasb.org/srt/2025 http://fasb.org/us-gaap/2025 http://xbrl.sec.gov/cyd/2025 http://xbrl.sec.gov/dei/2025 http://xbrl.sec.gov/ecd/2025 true true