2.2.0.25truefalse06065 - Disclosure - Derivative Instruments (Details Textuals)truefalseIn Millions, unless otherwise specifiedfalse1falsefalseUSDfalsefalse1/1/2011 - 12/31/2011 USD ($) $TwelveMonthsEnded_31Dec2011http://www.sec.gov/CIK0001031296duration2011-01-01T00:00:002011-12-31T00:00:00USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170PureStandardhttp://www.xbrl.org/2003/instancepurexbrli0SharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0MWHStandardhttp://firstenergycorp.com/2010-12-31MWHfe0USDUSD$2falsefalseUSDfalsefalse1/1/2010 - 12/31/2010 USD ($) USD ($) / shares $Jan-01-2010_Dec-31-2010http://www.sec.gov/CIK0001031296duration2010-01-01T00:00:002010-12-31T00:00:00USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170PureStandardhttp://www.xbrl.org/2003/instancepurexbrli0SharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0USDEPSDividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0MWHStandardhttp://firstenergycorp.com/2010-12-31MWHfe0USDUSD$3falsefalseUSDfalsefalse12/31/2009 USD ($) $BalanceAsOf_31Dec2009http://www.sec.gov/CIK0001031296instant2009-12-31T00:00:000001-01-01T00:00:00USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170SharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0USDUSD$2true0fe_DerivativeInstrumentsTextualsAbstractfefalsenadurationDerivative Instruments.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringDerivative Instruments.falsefalseDerivative Instruments (Textuals) [Abstract]3false0fe_ExpectedAdverseChangeInQuotedMarketPricesDerivativeInstrumentsfefalsenainstantExpected adverse change in quoted market prices derivative instruments.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsetruefalse00falsefalsefalsefalsefalse2truetruefalse0.100.10falsefalsefalsefalsefalse3falsetruefalse00falsefalsefalsefalsefalseOtherus-types:percentItemTypepureExpected adverse change in quoted market prices derivative instruments.No authoritative reference available.falsefalseExpected adverse change in quoted market prices of derivative instruments4false0fe_DecreaseNetIncomeDueToAdverseChangeInCommodityPricesfefalsedebitdurationDecrease net income due to adverse change in commodity prices.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse1600000016falsetruefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryDecrease net income due to adverse change in commodity prices.No authoritative reference available.falsefalseDecrease net income due to adverse change in commodity prices5false0fe_DecreaseNetIncomeDueToAdverseChangeInCommodityPricesNetOfTaxfefalsedebitdurationDecrease net income due to adverse change in commodity prices,Net of tax.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse1000000010falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryDecrease net income due to adverse change in commodity prices,Net of tax.No authoritative reference available.falsefalseDecrease net income due to adverse change in commodity prices, net of tax6false0fe_ExpectedIncreaseInInterestRateAssosiatedWithVariableRateDebtfefalsenainstantExpected increase in interest rate assosiated with variable rate debt.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsetruefalse00falsefalsefalsefalsefalse2truetruefalse0.100.10falsefalsefalsefalsefalse3falsetruefalse00falsefalsefalsefalsefalseOtherus-types:percentItemTypepureExpected increase in interest rate assosiated with variable rate debt.No authoritative reference available.falsefalseExpected increase in interest rate assosiated with variable rate debt7false0fe_DecreaseNetIncomeDueToIncreaseInInterestRatesAssociatedWithVariableRateDebtfefalsedebitdurationDecrease net income due to increase in interest rates associated with variable-rate debt.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse10000001falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryDecrease net income due to increase in interest rates associated with variable-rate debt.No authoritative reference available.falsefalseDecrease in annual net income due to increase in interest rate assosiated with variable rate debt8false0fe_UnamortizedLossesAssociatedWithPriorInterestRateHedgesfefalsedebitinstantUnamortized losses associated with prior interest rate hedges.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse9200000092falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryUnamortized losses associated with prior interest rate hedges.No authoritative reference available.falsefalseUnamortized losses associated with prior interest rate hedges9false0fe_UnamortizedLossesAssociatedWithPriorInterestRateHedgesNetOfTaxfefalsedebitinstantUnamortized losses associated with prior interest rate hedges net of tax.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse6000000060falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryUnamortized losses associated with prior interest rate hedges net of tax.No authoritative reference available.falsefalseUnamortized losses associated with prior interest rate hedges net of tax10false0fe_UnamortizedGainsIncludedInLongTermDebtAssociatedWithPriorFixedForFloatingInterestRateSwapAgreementsfefalsecreditinstantUnamortized gains included in long-term debt associated with prior fixed-for-floating interest rate swap agreements.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse124000000124falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryUnamortized gains included in long-term debt associated with prior fixed-for-floating interest rate swap agreements.No authoritative reference available.falsefalseGains included in long-term debt associated with prior fixed-for-floating interest rate swap agreements11false0fe_UnamortizedGainsIncludedInLongTermDebtAssociatedWithPriorFixedForFloatingInterestRateSwapAgreementsNetOfTaxfefalsecreditinstantUnamortized gains included in long term debt associated with prior fixed for floating interest rate swap agreements Net of...falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse8000000080falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryUnamortized gains included in long term debt associated with prior fixed for floating interest rate swap agreements Net of taxNo authoritative reference available.falsefalseGains included in long-term debt associated with prior fixed-for-floating interest rate swap agreements,net of tax12false0fe_ReclassificationsFromLongTermDebtIntoInterestExpensefefalsedebitdurationReclassifications from long-term debt into interest expense.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse1200000012falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryReclassifications from long-term debt into interest expense.No authoritative reference available.falsefalseReclassifications from long-term debt into interest expense13false0fe_UnamortizedGainsLossesIncludedInAoclAssociatedWithCommodityDerivativesfefalsedebitinstantUnamortized Gains Losses Included In Aocl Associated With Commodity Derivatives.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse80000008falsefalsefalsefalsefalse3truefalsefalse-15000000-15falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryUnamortized Gains Losses Included In Aocl Associated With Commodity Derivatives.No authoritative reference available.falsefalseTotal unamortized gains (losses) included in AOCL associated with commodity derivatives14false0fe_TotalUnamortizedGainsLossesIncludedInAoclAssociatedWithCommodityDerivativesNetOfTaxfefalsedebitinstantTotal Unamortized Gains Losses Included In Aocl Associated With Commodity Derivatives Net Of Tax.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse50000005falsefalsefalsefalsefalse3truefalsefalse-9000000-9falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryTotal Unamortized Gains Losses Included In Aocl Associated With Commodity Derivatives Net Of Tax.No authoritative reference available.falsefalseTotal unamortized gains (losses) included in AOCL associated with commodity derivatives, Net of tax15false0fe_ChangeResultedFromIncreaseRelatedToCurrentHedgingActivityNetOfTaxfefalsedebitdurationChange resulted from Increase related to current hedging activity, Net of tax.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse10000001falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryChange resulted from Increase related to current hedging activity, Net of tax.No authoritative reference available.falsefalseChange resulted from Increase related to current hedging activity, Net of tax16false0fe_DecreaseDueToNetHedgeLossesReclassifiedToEarningsfefalsedebitdurationDecrease due to net hedge losses reclassified to earnings.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse1500000015falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryDecrease due to net hedge losses reclassified to earnings.No authoritative reference available.falsefalseDecrease due to net hedge losses reclassified to earnings17false0fe_NetDeferredLossesOnDerivativeInstrumentsInAccumulatedOtherComprehensiveLossesAfterTaxToBeReclassifiedToEarningsfefalsedebitdurationNet deferred losses on derivative instruments in accumulated other comprehensive losses after tax to be reclassified to...falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse30000003falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryNet deferred losses on derivative instruments in accumulated other comprehensive losses after tax to be reclassified to earnings.No authoritative reference available.falsefalseNet deferred losses on derivative instruments in accumulated other comprehensive losses after tax to be reclassified to earnings18false0fe_CompanyPostedCollateralRelatedToNetLiabilityPositionsfefalsedebitinstantCompany Posted Collateral Related To Net Liability Positions.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse156000000156falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCompany Posted Collateral Related To Net Liability Positions.No authoritative reference available.falsefalseFirstEnergy posted of collateral related to net liability positions19false0fe_NetLiabilityPositionUnderCommodityDerivativeContractsfefalsedebitinstantNet Liability Position Under Commodity Derivative Contracts.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse107000000107falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryNet Liability Position Under Commodity Derivative Contracts.No authoritative reference available.falsefalseNet liability position under commodity derivative contracts20false0fe_CounterpartiesFundsRelatedToAssetPositionsfefalsenainstantCounterparties funds related to asset positions.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:integerItemTypeintegerCounterparties funds related to asset positions.No authoritative reference available.falsefalseCounterparties funds related to asset positions21false0us-gaap_DerivativeNetLiabilityPositionAggregateFairValueus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse102000000102falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe 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 falsefalseThe aggregate fair value of derivative instruments with credit risk-related contingent features22false0us-gaap_CollateralAlreadyPostedAggregateFairValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse9100000091falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe 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 falsefalseThe aggregate fair value of derivative instruments with credit risk-related contingent features whose collateral has been posted23false0us-gaap_AdditionalCollateralAggregateFairValueus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse2400000024falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe 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 falsefalseAdditional collateral related to commodity derivatives24false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://firstenergycorp.com/role/derivativeinstrumentsdetailstextuals1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalse4falsefalseUSDtruefalse{us-gaap_DerivativeByNatureAxis} : Cash Flow Hedges [Member] 12/31/2010 USD ($) $BalanceAsOf_31Dec2010_Cash_Flow_Hedges_Memberhttp://www.sec.gov/CIK0001031296instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseCash Flow Hedges [Member]us-gaap_DerivativeByNatureAxisxbrldihttp://xbrl.org/2006/xbrldife_CashFlowHedgesMemberus-gaap_DerivativeByNatureAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$OthernaNo definition available.No authoritative reference available.falsefalseCash Flow Hedges [Member]25true0fe_DerivativeInstrumentsTextualsAbstractfefalsenadurationDerivative Instruments.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringDerivative Instruments.falsefalseDerivative Instruments (Textuals) [Abstract]26false0fe_LossesToBeAmortizedToInterestExpensesDuringNextTweleveMonthsfefalsedebitinstantLosses to be amortized to interest expenses during next tweleve months.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse1100000011falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryLosses to be amortized to interest expenses during next tweleve months.No authoritative reference available.falsefalseLosses to be amortized to interest expenses during next twelve months27false0natruenanaNo definition available.falsetruefalsefalsefalsefalsefalsefalsefalsefalsehttp://firstenergycorp.com/role/derivativeinstrumentsdetailstextuals1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalse5falsefalseUSDtruefalse{us-gaap_DerivativeByNatureAxis} : Fair Value Hedging [Member] 12/31/2010 USD ($) $BalanceAsOf_31Dec2010_Fair_Value_Hedging_Memberhttp://www.sec.gov/CIK0001031296instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseFair Value Hedging [Member]us-gaap_DerivativeByNatureAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_FairValueHedgingMemberus-gaap_DerivativeByNatureAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$OthernaNo definition available.No authoritative reference available.falsefalseFair Value Hedging [Member]28true0fe_DerivativeInstrumentsTextualsAbstractfefalsenadurationDerivative Instruments.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalseOtherxbrli:stringItemTypestringDerivative Instruments.falsefalseDerivative Instruments (Textuals) [Abstract]29false0fe_LossesToBeAmortizedToInterestExpensesDuringNextTweleveMonthsfefalsedebitinstantLosses to be amortized to interest expenses during next tweleve months.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00falsefalsefalsefalsefalse2truefalsefalse2200000022falsetruefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryLosses to be amortized to interest expenses during next tweleve months.No authoritative reference available.falsefalseLosses to be amortized to interest expenses during next twelve months328Derivative Instruments (Details Textuals) (USD $)MillionsUnKnownUnKnownUnKnowntruetrue