2.2.0.7 false Consolidated Statements of Comprehensive Income (Unaudited) (USD $) 00120 - Statement - Consolidated Statements of Comprehensive Income (Unaudited) true false In Thousands 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 $ 2 Consolidated Statements of Comprehensive Income (Unaudited) [Abstract] 0 us-gaap_StatementOfIncomeAndComprehensiveIncomeAbstract us-gaap true na duration No definition available. false false false false false true 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 xbrli:stringItemType string No definition available. false 3 NET INCOME 1 us-gaap_ProfitLoss us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 true true false false 256000000 256000 false false false 2 true true false false 408000000 408000 false false false 3 true true false false 405000000 405000 false false false 4 true true false false 523000000 523000 false false false xbrli:monetaryItemType monetary The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph A1, A4, A5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 5 -Subparagraph b Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 29 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph a Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph c(1) true 4 OTHER COMPREHENSIVE INCOME: 1 fe_OtherComprehensiveIncomeLossAbstract fe false na duration Other Comprehensive Income Loss Abstract. 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 xbrli:stringItemType string Other Comprehensive Income Loss Abstract. false 5 Pension and other postretirement benefits 2 us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentBeforeTaxPeriodIncreaseDecrease us-gaap true na duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 17000000 17000000 false false false 2 false true false false 469000000 469000000 false false false 3 false true false false 30000000 30000000 false false false 4 false true false false 504000000 504000000 false false false xbrli:monetaryItemType monetary Amounts recognized in other comprehensive income (but not yet recognized in net periodic benefit cost), including the net gain (loss) and net prior service cost (credit) arising during the period. Also includes reclassification adjustments out of other comprehensive income as a result of being recognized as components of net periodic benefit cost for the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph C3 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 130 -Paragraph 14, 17, 22, 26 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph c(3) Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 158 -Paragraph 7 -Subparagraph a false 6 Unrealized gain on derivative hedges 2 us-gaap_OtherComprehensiveIncomeDerivativesQualifyingAsHedgesBeforeTaxPeriodIncreaseDecrease us-gaap true na duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 6000000 6000000 false false false 2 false true false false 23000000 23000000 false false false 3 false true false false 10000000 10000000 false false false 4 false true false false 38000000 38000000 false false false xbrli:monetaryItemType monetary Pre tax change in accumulated gains and losses from derivative instruments designated and qualifying as the effective portion of cash flow hedges, net of reclassifications into earnings during the period. A cash flow hedge is a hedge of the exposure to variability in the cash flows of a recognized asset or liability or a forecasted transaction that is attributable to a particular risk. Includes an entity's share of an equity investee's increase (decrease) in deferred hedging gains or losses. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 130 -Paragraph 14, 17, 20, 24, 26 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 130 -Paragraph 14, 17, 20, 26 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 45 -Subparagraph b(1) Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 31, 46 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph c(3) Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 130 -Paragraph 24 -Subparagraph b Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 46 false 7 Change in unrealized gain on available-for-sale securities 2 us-gaap_OtherComprehensiveIncomeAvailableForSaleSecuritiesAdjustmentBeforeTaxPeriodIncreaseDecrease us-gaap true na duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 6000000 6000000 false false false 2 false true false false 37000000 37000000 false false false 3 false true false false 12000000 12000000 false false false 4 false true false false 32000000 32000000 false false false xbrli:monetaryItemType monetary Gross appreciation or the gross loss in value of the total of unsold available-for-sale securities (except when designated as a fair value hedge or which had been determined to have had an other than temporary decline in fair value below its amortized cost basis) at the end of an accounting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 130 -Paragraph 19 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 13 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 16 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 130 -Paragraph 26 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 130 -Paragraph 24 -Subparagraph b Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 130 -Paragraph 14 Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph c(3) Reference 8: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 130 -Paragraph 17 true 8 Other comprehensive income 2 us-gaap_OtherComprehensiveIncomeLossBeforeTaxPeriodIncreaseDecrease us-gaap true na duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 29000000 29000000 false false false 2 false true false false 529000000 529000000 false false false 3 false true false false 52000000 52000000 false false false 4 false true false false 574000000 574000000 false false false xbrli:monetaryItemType monetary This element represents Other Comprehensive Income (Loss), Before Tax, for the period. The pretax revenues, expenses, gains, and losses that under generally accepted accounting principles are included in comprehensive income, but excluded from net income. Includes the entity's proportionate share of an investee's equity adjustments for other comprehensive income. 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Includes deferred gains (losses) on qualifying hedges, unrealized holding gains (losses) on available-for-sale securities, minimum pension liability, and cumulative translation adjustment. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph c(3) Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 130 -Paragraph 22, 23, 24, 25 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 10 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 31 -Article 5 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 true 11 COMPREHENSIVE INCOME 1 us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest 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 276000000 276000000 false false false 2 false true false false 710000000 710000000 false false false 3 false true false false 441000000 441000000 false false false 4 false true false false 855000000 855000000 false false false xbrli:monetaryItemType monetary The change in equity [net assets] of a business enterprise during a period from transactions and other events and circumstances from non-owner sources which are attributable to the economic entity, including both controlling (parent) and noncontrolling interests. It includes all changes in equity during a period except those resulting from investments by owners and distributions to owners, including any and all transactions which are directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph A5 -Appendix A Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 29 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph a false 12 LESS:COMPREHENSIVE LOSS ATTRIBUTABLE TO NONCONTROLLING INTEREST 1 us-gaap_NetIncomeLossAttributableToNoncontrollingInterest us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false -9000000 -9000000 false false false 2 false true false false -6000000 -6000000 false false false 3 false true false false -15000000 -15000000 false false false 4 false true false false -10000000 -10000000 false false false xbrli:monetaryItemType monetary The portion of net income (loss) attributable to the noncontrolling interest (if any) deducted in order to derive the portion attributable to the parent. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph a Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph c(1) Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph A1, A4, A5 false 13 COMPREHENSIVE INCOME AVAILABLE TO FIRSTENERGY CORP. 1 us-gaap_ComprehensiveIncomeNetOfTax us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 true true false false 285000000 285000000 false false false 2 true true false false 716000000 716000000 false false false 3 true true false false 456000000 456000000 false false false 4 true true false false 865000000 865000000 false false false xbrli:monetaryItemType monetary The change in equity [net assets] of a business enterprise during a period from transactions and other events and circumstances from non-owner sources which are attributable to the reporting entity. It includes all changes in equity during a period except those resulting from investments by owners and distributions to owners, but excludes any and all transactions which are directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph A5 -Appendix A Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 30 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph c(3) Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 8, 9, 10, 11, 12, 13, 14 true 4 12 false Thousands UnKnown UnKnown false true