2.2.0.7 true Derivative Instruments (Details) (USD $) 00604 - Disclosure - Derivative Instruments (Details) true false false false 1 USD false false USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 EPS Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 $ false 2 USD false false USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 EPS Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 $ false 3 USD false false USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Tons Standard http://firstenergycorp.com/20100331 tons fe 0 Percent Standard http://www.xbrl.org/2003/instance pure xbrli 0 kV Standard http://firstenergycorp.com/20100331 kV fe 0 Customers Standard http://firstenergycorp.com/20100331 Customers fe 0 Days Standard http://firstenergycorp.com/20100331 Days fe 0 EPS Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 $ false 4 USD false false USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 kV Standard http://firstenergycorp.com/20100331 kV fe 0 EPS Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 $ false 5 USD false false USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Tons Standard http://firstenergycorp.com/20100331 tons fe 0 Percent Standard http://www.xbrl.org/2003/instance pure xbrli 0 MWH Standard http://firstenergycorp.com/20100331 MWH fe 0 Generating_Facilities Standard http://firstenergycorp.com/20100331 Generating_Facilities fe 0 Square_Miles Standard http://firstenergycorp.com/20100331 Square_Miles fe 0 Gallons Standard http://firstenergycorp.com/20100331 Gallons fe 0 mmBTU Standard http://firstenergycorp.com/20100331 mmBTU fe 0 Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 $ false 6 USD false false USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 $ 8 Fair value of commodity derivatives 2 us-gaap_DerivativeFairValueOfDerivativeNetAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 11 Total Commodity Derivatives Assets 2 us-gaap_DerivativeAssetDesignatedAsHedgingInstrumentFairValue us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 true true false false 245000000 245000000 false false false 6 true true false false 233000000 233000000 false false false xbrli:monetaryItemType monetary Fair value of a derivative asset (or nonderivative instrument) that is designated and qualifies as a hedging instrument, presented on a gross basis even when the derivative instrument is subject to master netting arrangements and qualifies for net presentation in the statement of financial position. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 205G Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 44C -Subparagraph a -Clause 1 true 12 Total Commodity Derivatives Liabilities 2 us-gaap_DerivativeLiabilityDesignatedAsHedgingInstrumentFairValue us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 969000000 969000000 false false false 6 false true false false 876000000 876000000 false false false xbrli:monetaryItemType monetary Fair value of a derivative liability (or nonderivative instrument) that is designated and qualifies as a hedging instrument, presented on a gross basis even when the derivative instrument is subject to master netting arrangements and qualifies for net presentation in the statement of financial position. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 205G Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 44C -Subparagraph a -Clause 1 true 13 Volume of First Energy's outstanding derivative transactions 2 fe_VolumeOfParentCompanysOutstandingDerivativeTransactionAbstract fe false na duration Volume Of Parent Companys Outstanding Derivative Transaction. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string Volume Of Parent Companys Outstanding Derivative Transaction. false 14 Purchases in (MWH, Gallons, mmBtu) 2 fe_VolumeOfDerivativesPurchases fe false na instant Volume Of Derivatives Purchases. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 21596000 21596000 false false false 6 false false false false 0 0 false false false xbrli:integerItemType integer Volume Of Derivatives Purchases. No authoritative reference available. false 15 Sales in (MWH, Gallons, mmBtu) 2 fe_VolumeOfDerivativesSales fe false na instant Volume Of Derivatives Sales. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false -19965000 -19965000 false false false 6 false false false false 0 0 false false false xbrli:integerItemType integer Volume Of Derivatives Sales. No authoritative reference available. false 16 Net in (MWH, Gallons, mmBtu) 2 fe_VolumeOfDerivativesNet fe false na instant Volume Of Derivatives Net. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 1631000 1631000 false false false 6 false false false false 0 0 false false false xbrli:integerItemType integer Volume Of Derivatives Net. No authoritative reference available. false 17 The effect of derivative instruments on the statements of income and comprehensive income for instruments designated in cash flow hedging relationships and not in hedging relationships 2 fe_EffectOfDerivativeInstrumentsOnStatementsOfIncomeAndComprehensiveIncomeForInstrumentsDesignatedInCashFlowHedgingRelationshipsAndNotInHedgingRelationshipsAbstract fe false na duration The effect of derivative instruments on the statements of income and comprehensive income for instruments designated in cash... false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string The effect of derivative instruments on the statements of income and comprehensive income for instruments designated in cash flow hedging relationships and not in hedging relationships. false 18 Gain (Loss) Recognized in AOCL (Effective Portion) 2 us-gaap_DerivativeInstrumentsGainLossRecognizedInOtherComprehensiveIncomeEffectivePortionNet us-gaap true credit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false -8000000 -8000000 false false false 2 false true false false 8000000 8000000 false false false 3 false true false false -14000000 -14000000 false false false 4 false true false false -2000000 -2000000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The effective portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments that was recognized in other comprehensive income during the current period. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 205G Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 44C -Subparagraph b -Clause 2 false 20 Unrealized Gain (Loss) Recognized in: 2 us-gaap_UnrealizedGainLossOnDerivatives us-gaap true credit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false true false false -154000000 -154000000 false false false 3 false true false false -276000000 -276000000 false false false 4 false true false false -381000000 -381000000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The increases (decreases) in the market value of derivative instruments, including options, swaps, futures, and forward contracts, which were included in earnings in the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 false 21 Realized Gain (Loss) Reclassified to: 2 fe_DerivativeInstrumentsGainLossNetReclassified fe false credit duration Derivative instruments gain loss net reclassified. false false false false false false false false false false false verboselabel false 1 false true false false -99000000 -99000000 false false false 2 false true false false -96000000 -96000000 false false false 3 false true false false -193000000 -193000000 false false false 4 false true false false -170000000 -170000000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Derivative instruments gain loss net reclassified. No authoritative reference available. false 22 Derivative Instruments (Textuals) [Abstract] 2 fe_DerivativeInstrumentsTextualsAbstract fe false na duration Derivative Instruments. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string Derivative Instruments. false 23 Expected adverse change in quoted market prices of derivative instruments 2 fe_ExpectedAdverseChangeInQuotedMarketPricesDerivativeInstruments fe false na instant Expected adverse change in quoted market prices derivative instruments. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 10 10 false false false 6 false false false false 0 0 false false false us-types:percentItemType pure Expected adverse change in quoted market prices derivative instruments. No authoritative reference available. false 24 Decrease net income due to adverse change in commodity prices 2 fe_DecreaseNetIncomeDueToAdverseChangeInCommodityPrices fe false debit duration Decrease net income due to adverse change in commodity prices. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 9000000 9000000 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Decrease net income due to adverse change in commodity prices. No authoritative reference available. false 25 Decrease net income due to increase in interest rates associated with variable-rate debt 2 fe_DecreaseNetIncomeDueToIncreaseInInterestRatesAssociatedWithVariableRateDebt fe false debit duration Decrease net income due to increase in interest rates associated with variable-rate debt. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 1000000 1000000 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Decrease net income due to increase in interest rates associated with variable-rate debt. No authoritative reference available. false 26 First Energy terminated forward swaps with a notional value 2 fe_NotionalValueOfTerminatedForwardSwaps fe false debit duration Notional value of Terminated forward swaps. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 3150000000 3150000000 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Notional value of Terminated forward swaps. No authoritative reference available. false 27 Unamortized losses associated with prior interest rate hedges 2 fe_UnamortizedLossesAssociatedWithPriorInterestRateHedges fe false debit instant Unamortized losses associated with prior interest rate hedges. false false false false false false false false false false false false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 109000000 109000000 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Unamortized losses associated with prior interest rate hedges. No authoritative reference available. false 28 Unamortized losses associated with prior interest rate hedges net of tax 2 fe_UnamortizedLossesAssociatedWithPriorInterestRateHedgesNetOfTax fe false debit instant Unamortized losses associated with prior interest rate hedges net of tax. false false false false false false false false false false false false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 71000000 71000000 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Unamortized losses associated with prior interest rate hedges net of tax. No authoritative reference available. false 29 Losses to be amortized to interest expenses during next twelve months 2 fe_LossesToBeAmortizedToInterestExpensesDuringNextTweleveMonths fe false debit instant Losses to be amortized to interest expenses during next tweleve months. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 11000000 11000000 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Losses to be amortized to interest expenses during next tweleve months. No authoritative reference available. false 30 Total unamortized losses included in AOCL associated with commodity derivatives 2 fe_UnamortizedLossesIncludedInAoclAssociatedWithCommodityDerivatives fe false debit instant unamortized losses included in AOCL associated with commodity derivatives. false false false false false false false false false false false terselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 11000000 11000000 false false false 6 false true false false 15000000 15000000 false false false xbrli:monetaryItemType monetary unamortized losses included in AOCL associated with commodity derivatives. No authoritative reference available. false 31 Total unamortized losses included in AOCL associated with commodity derivatives, Net of tax 2 fe_TotalUnamortizedLossesIncludedInAoclAssociatedWithCommodityDerivativesNetOfTax fe false debit instant Total unamortized losses included in AOCL associated with commodity derivatives, Net of tax. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 7000000 7000000 false false false 6 false true false false 9000000 9000000 false false false xbrli:monetaryItemType monetary Total unamortized losses included in AOCL associated with commodity derivatives, Net of tax. No authoritative reference available. false 32 Change resulted from decrease related to current hedging activity, Net of tax 2 fe_ChangeResultedFromDecreaseRelatedToCurrentHedgingActivityNetOfTax fe false debit duration Change resulted from decrease related to current hedging activity, Net of tax. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 12000000 12000000 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Change resulted from decrease related to current hedging activity, Net of tax. No authoritative reference available. false 33 Net deferred losses on derivative instruments in accumulated other comprehensive losses after tax to be reclassified to earnings 2 fe_NetDeferredLossesOnDerivativeInstrumentsInAccumulatedOtherComprehensiveLossesAfterTaxToBeReclassifiedToEarnings fe false debit duration Net deferred losses on derivative instruments in accumulated other comprehensive losses after tax to be reclassified to... false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 10000000 10000000 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Net deferred losses on derivative instruments in accumulated other comprehensive losses after tax to be reclassified to earnings. No authoritative reference available. false 34 The aggregate fair value of derivative instruments with credit risk-related contingent features whose collateral has been posted 2 us-gaap_CollateralAlreadyPostedAggregateFairValue us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 194000000 194000000 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The aggregate fair value of assets that are already posted, at the end of the reporting period, as collateral for derivative instruments with credit-risk-related contingent features. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 44D -Subparagraph c false 35 The aggregate fair value of derivative instruments with credit risk-related contingent features 2 us-gaap_DerivativeNetLiabilityPositionAggregateFairValue us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 177000000 177000000 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The aggregate fair value amounts of derivative instruments that contain credit-risk-related contingent features that are in a net liability position at the end of the reporting period. For nonderivative instruments that are designated and qualify as hedging instruments, the fair value amounts are the carrying value of the nonderivative hedging instrument, including the adjustment for the foreign currency transaction gain or loss on that instrument. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 44D -Subparagraph b false 36 Additional collateral related to commodity derivatives 2 us-gaap_AdditionalCollateralAggregateFairValue us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 37000000 37000000 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The aggregate fair value of additional assets that would be required to be posted as collateral for derivative instruments with credit-risk-related contingent features if the credit-risk-related contingent features were triggered at the end of the reporting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 44D -Subparagraph c false 37 Net of tax decrease due to adverse change in commodity prices 2 fe_NetOfTaxDecreaseDueToAdverseChangeInCommodityPrices fe false debit duration Net of tax decrease due to adverse change in commodity prices. false false false false false false false false false false false false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 6000000 6000000 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Net of tax decrease due to adverse change in commodity prices. No authoritative reference available. false 38 Hypothetical increase in the interest rates 2 fe_HypotheticalIncreaseInTheInterestRates fe false na instant Hypothetical increase in the interest rates. false false false false false false false false false false false false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 10 10 false false false 6 false false false false 0 0 false false false us-types:percentItemType pure Hypothetical increase in the interest rates. No authoritative reference available. false 39 Cash proceeds received of May termination 2 fe_CashProceedsReceivedOfMayTermination fe false debit instant Cash proceeds received of May termination. false false false false false false false false false false false false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 43100000 43100000 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Cash proceeds received of May termination. No authoritative reference available. false 40 Accrued interest allocation for May termination 2 fe_AccruedInterestAllocationForMayTermination fe false credit instant Accrued interest allocation for May termination. false false false false false false false false false false false false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Accrued interest allocation for May termination. No authoritative reference available. false 41 June fixed-for-floating interest rateswap agreements execution notional amount 2 fe_JuneFixedForFloatingInterestRateSwapAgreementsExecutionNotionalAmount fe false debit instant June fixed-for-floating interest rateswap agreements execution notional amount. false false false false false false false false false false false false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 3200000000 3200000000 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary June fixed-for-floating interest rateswap agreements execution notional amount. No authoritative reference available. false 42 Debt underlying the June fixed-for-floating interest rate swap agreements execution 2 fe_DebtUnderlyingTheJuneFixedForFloatingInterestRateSwapAgreementsExecution fe false credit instant Debt underlying the June fixed-for-floating interest rate swap agreements execution. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 3200000000 3200000000 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Debt underlying the June fixed-for-floating interest rate swap agreements execution. No authoritative reference available. false 43 July notional amount of terminated fixed-for-floating interest rate swap agreements 2 fe_JulyNotionalAmountOfTerminatedFixedForFloatingInterestRateSwapAgreements fe false debit instant July notional amount of terminated fixed-for-floating interest rate swap agreements. false false false false false false false false false false false false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 3200000000 3200000000 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary July notional amount of terminated fixed-for-floating interest rate swap agreements. No authoritative reference available. false 44 Cash proceeds received of July termination 2 fe_CashProceedsReceivedOfJulyTermination fe false debit instant Cash proceeds received of July termination. false false false false false false false false false false false false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 83600000 83600000 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Cash proceeds received of July termination. No authoritative reference available. false 45 Net of tax change increase related to current hedging activity 2 fe_NetOfTaxChangeIncreaseRelatedToCurrentHedgingActivity fe false debit duration Net of tax change increase related to current hedging activity. false false false false false false false false false false false false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 10000000 10000000 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Net of tax change increase related to current hedging activity. No authoritative reference available. false 46 Collateral has been posted related to fair value of credit related contingent features 2 fe_CollateralHasBeenPostedRelatedToFairValueOfCreditRelatedContingentFeatures fe false debit instant Collateral has been posted related to fair value of credit related contingent features. false false false false false false false false false false false false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 194000000 194000000 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Collateral has been posted related to fair value of credit related contingent features. No authoritative reference available. false 47 Weighted average fixed interest rate of interest of interest rate swaps 2 fe_WeightedAverageFixedInterestRateOfInterestOfInterestRateSwaps fe false na instant Weighted average fixed interest rate of interest of interest rate swaps. false false false false false false false false false false false false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 6 6 false false false 6 false false false false 0 0 false false false us-types:percentItemType pure Weighted average fixed interest rate of interest of interest rate swaps. No authoritative reference available. false 48 Current weighted average variable rate of interest rate swaps 2 fe_CurrentWeightedAverageVariableRateOfInterestRateSwaps fe false na instant Current weighted average variable rate of interest rate swaps. false false false false false false false false false false false false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 4 4 false false false 6 false false false false 0 0 false false false us-types:percentItemType pure Current weighted average variable rate of interest rate swaps. 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No authoritative reference available. false 1830 The effect of derivative instruments on the statements of income and comprehensive income for instruments designated in cash flow hedging relationships and not in hedging relationships 2 fe_EffectOfDerivativeInstrumentsOnStatementsOfIncomeAndComprehensiveIncomeForInstrumentsDesignatedInCashFlowHedgingRelationshipsAndNotInHedgingRelationshipsAbstract fe false na duration The effect of derivative instruments on the statements of income and comprehensive income for instruments designated in cash... false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string The effect of derivative instruments on the statements of income and comprehensive income for instruments designated in cash flow hedging relationships and not in hedging relationships. false 1832 Effective Gain (Loss) Reclassified to:(1) 2 us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet us-gaap true credit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false -3000000 -3000000 false false false 2 false true false false -4000000 -4000000 false false false 3 false true false false -6000000 -6000000 false false false 4 false true false false -4000000 -4000000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The income statement location of the effective portion of net gain or loss reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments. 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No authoritative reference available. false 1879 The effect of derivative instruments on the statements of income and comprehensive income for instruments designated in cash flow hedging relationships and not in hedging relationships 2 fe_EffectOfDerivativeInstrumentsOnStatementsOfIncomeAndComprehensiveIncomeForInstrumentsDesignatedInCashFlowHedgingRelationshipsAndNotInHedgingRelationshipsAbstract fe false na duration The effect of derivative instruments on the statements of income and comprehensive income for instruments designated in cash... false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string The effect of derivative instruments on the statements of income and comprehensive income for instruments designated in cash flow hedging relationships and not in hedging relationships. false 1881 Effective Gain (Loss) Reclassified to:(1) 2 us-gaap_DerivativeInstrumentsGainLossReclassifiedFromAccumulatedOCIIntoIncomeEffectivePortionNet us-gaap true credit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false -1000000 -1000000 false false false 2 false true false false -4000000 -4000000 false false false 3 false true false false -2000000 -2000000 false false false 4 false true false false -8000000 -8000000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The income statement location of the effective portion of net gain or loss reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments. 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No authoritative reference available. false 1928 The effect of derivative instruments on the statements of income and comprehensive income for instruments designated in cash flow hedging relationships and not in hedging relationships 2 fe_EffectOfDerivativeInstrumentsOnStatementsOfIncomeAndComprehensiveIncomeForInstrumentsDesignatedInCashFlowHedgingRelationshipsAndNotInHedgingRelationshipsAbstract fe false na duration The effect of derivative instruments on the statements of income and comprehensive income for instruments designated in cash... false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string The effect of derivative instruments on the statements of income and comprehensive income for instruments designated in cash flow hedging relationships and not in hedging relationships. false 1931 Unrealized Gain (Loss) Recognized in: 2 us-gaap_UnrealizedGainLossOnDerivatives us-gaap true credit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false true false false 0 0 false false false 3 false false false false 0 0 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The increases (decreases) in the market value of derivative instruments, including options, swaps, futures, and forward contracts, which were included in earnings in the period. 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No authoritative reference available. false 1961 Fuel Expense [Member] | Other [Member] 0 na true na na No definition available. false true false false false false false false false false false http://firstenergycorp.com/role/disclosurederivativeinstrumentsdetails false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false false 109 USD true false false false Fuel Expense [Member] us-gaap_DerivativeInstrumentsGainLossByIncomeStatementLocationAxis xbrldi http://xbrl.org/2006/xbrldi fe_FuelExpenseMember us-gaap_DerivativeInstrumentsGainLossByIncomeStatementLocationAxis explicitMember false false Other [Member] us-gaap_DerivativesFairValueByDerivativeInstrumentRiskAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_OtherMember us-gaap_DerivativesFairValueByDerivativeInstrumentRiskAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 110 USD true false false false Fuel Expense [Member] us-gaap_DerivativeInstrumentsGainLossByIncomeStatementLocationAxis xbrldi http://xbrl.org/2006/xbrldi fe_FuelExpenseMember us-gaap_DerivativeInstrumentsGainLossByIncomeStatementLocationAxis explicitMember false false Other [Member] us-gaap_DerivativesFairValueByDerivativeInstrumentRiskAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_OtherMember us-gaap_DerivativesFairValueByDerivativeInstrumentRiskAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ na No definition available. No authoritative reference available. false 1977 The effect of derivative instruments on the statements of income and comprehensive income for instruments designated in cash flow hedging relationships and not in hedging relationships 2 fe_EffectOfDerivativeInstrumentsOnStatementsOfIncomeAndComprehensiveIncomeForInstrumentsDesignatedInCashFlowHedgingRelationshipsAndNotInHedgingRelationshipsAbstract fe false na duration The effect of derivative instruments on the statements of income and comprehensive income for instruments designated in cash... false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string The effect of derivative instruments on the statements of income and comprehensive income for instruments designated in cash flow hedging relationships and not in hedging relationships. false 1980 Unrealized Gain (Loss) Recognized in: 2 us-gaap_UnrealizedGainLossOnDerivatives us-gaap true credit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false true false false 2000000 2000000 false false false 3 false false false false 0 0 false false false 4 false true false false 2000000 2000000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The increases (decreases) in the market value of derivative instruments, including options, swaps, futures, and forward contracts, which were included in earnings in the period. 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No authoritative reference available. false 2026 The effect of derivative instruments on the statements of income and comprehensive income for instruments designated in cash flow hedging relationships and not in hedging relationships 2 fe_EffectOfDerivativeInstrumentsOnStatementsOfIncomeAndComprehensiveIncomeForInstrumentsDesignatedInCashFlowHedgingRelationshipsAndNotInHedgingRelationshipsAbstract fe false na duration The effect of derivative instruments on the statements of income and comprehensive income for instruments designated in cash... false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string The effect of derivative instruments on the statements of income and comprehensive income for instruments designated in cash flow hedging relationships and not in hedging relationships. false 2027 Gain (Loss) Recognized in AOCL (Effective Portion) 2 us-gaap_DerivativeInstrumentsGainLossRecognizedInOtherComprehensiveIncomeEffectivePortionNet us-gaap true credit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false -8000000 -8000000 false false false 2 false true false false 6000000 6000000 false false false 3 false true false false -13000000 -13000000 false false false 4 false true false false 4000000 4000000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The effective portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments that was recognized in other comprehensive income during the current period. 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No authoritative reference available. false 2075 The effect of derivative instruments on the statements of income and comprehensive income for instruments designated in cash flow hedging relationships and not in hedging relationships 2 fe_EffectOfDerivativeInstrumentsOnStatementsOfIncomeAndComprehensiveIncomeForInstrumentsDesignatedInCashFlowHedgingRelationshipsAndNotInHedgingRelationshipsAbstract fe false na duration The effect of derivative instruments on the statements of income and comprehensive income for instruments designated in cash... false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string The effect of derivative instruments on the statements of income and comprehensive income for instruments designated in cash flow hedging relationships and not in hedging relationships. false 2076 Gain (Loss) Recognized in AOCL (Effective Portion) 2 us-gaap_DerivativeInstrumentsGainLossRecognizedInOtherComprehensiveIncomeEffectivePortionNet us-gaap true credit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false true false false 0 0 false false false 3 false true false false -1000000 -1000000 false false false 4 false true false false -7000000 -7000000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The effective portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments that was recognized in other comprehensive income during the current period. 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