2.2.0.7 true Variable Interest Entities (Details) (USD $) 00607 - Disclosure - Variable Interest Entities (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 Pure Standard http://www.xbrl.org/2003/instance pure 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 Pure Standard http://www.xbrl.org/2003/instance pure xbrli 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 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 $ 6 Purchased power costs from entities: 2 fe_PurchasedPowerCostsFromEntitiesAbstract fe false na duration Purchased power costs from entities. 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 Purchased power costs from entities. false 7 Purchased power costs from entities 2 fe_LongTermContractForPurchaseOfElectricPowerCostIncurred fe false debit duration Long Term Contract For Purchase of Electric Power Cost Incurred. false false false false false false false false false false false verboselabel false 1 true true false false 73000000 73000000 false false false 2 true true false false 58000000 58000000 false false false 3 true true false false 190000000 190000000 false false false 4 true true false false 173000000 173000000 false false false xbrli:monetaryItemType monetary Long Term Contract For Purchase of Electric Power Cost Incurred. No authoritative reference available. false 8 Variable Interest Entities (Textuals) [Abstract] 2 fe_VariableInterestEntitiesTextualsAbstract fe false na duration Variable Interest Entities. 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 Variable Interest Entities. false 9 Net losses of the noncontrolling interests 2 us-gaap_NetIncomeLossAttributableToNoncontrollingInterest us-gaap true debit duration No definition available. false false false false false false false false false false true negated false 1 false true false false 4000000 4000000 false false false 2 false true false false 4000000 4000000 false false false 3 false true false false 19000000 19000000 false false false 4 false true false false 14000000 14000000 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 10 Distributions to owners 2 fe_VariableInterestEntitiesDistributionsToOwners fe false credit duration Variable interest entities distributions to owners. 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 5000000 5000000 false false false 4 false false false false 0 0 false false false xbrli:monetaryItemType monetary Variable interest entities distributions to owners. No authoritative reference available. false 11 Net present value of FirstEnergy's consolidated sale and leaseback operating lease commitments 2 fe_VariableInterestEntitiesNetPresentValueOfParentCompanyConsolidatedSaleAndLeasebackOperatingLeaseCommitments fe false credit duration Variable interest entities net present value of parent company consolidated sale and leaseback operating lease commitments. 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 1700000000 1700000000 false false false 4 false false false false 0 0 false false false xbrli:monetaryItemType monetary Variable interest entities net present value of parent company consolidated sale and leaseback operating lease commitments. No authoritative reference available. false 12 Number of long-term power purchase agreements maintained by FirstEnergy with NUG entities 2 fe_NumberOfLongTermPowerPurchaseAgreementsMaintainedByParentCompanyWithNonUtilityGenerationEntities fe false na duration Number of long term power purchase agreements maintained by parent company with Non utility generation entities. 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 21 21 false false false 4 false false false false 0 0 false false false xbrli:integerItemType integer Number of long term power purchase agreements maintained by parent company with Non utility generation entities. No authoritative reference available. false 13 Transition bonds outstanding 2 us-gaap_LongTermTransitionBond us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 319000000 319000000 false false false 2 false false false false 0 0 false false false 3 false true false false 319000000 319000000 false false false 4 false false false false 0 0 false false false xbrli:monetaryItemType monetary Long-Term transition bonds are bonds under the Competition Act in which the proceeds of Transition Bonds are required to be used principally to reduce qualified stranded costs and the related capitalization of the utility. This represents the noncurrent portion. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 false 14 FES [Member] 0 na true na na No definition available. false true false false false false false false false false false http://firstenergycorp.com/role/disclosurevariableinterestentitiesdetails 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 false 5 USD true false false false FES [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_SubsidiaryEightMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ na No definition available. No authoritative reference available. false 15 Net exposure to loss based upon the casualty value provisions 2 fe_NetExposureToLossBasedUponCasualtyValueProvisionsAbstract fe false na duration Net exposure to loss based upon casualty value provisions. 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 Net exposure to loss based upon casualty value provisions. false 16 Maximum Exposure 2 us-gaap_VariableInterestMaximumExposureToLoss us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 1376000000 1376000000 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:monetaryItemType monetary Quantifies the entity's maximum exposure to loss. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number FAS140-4 and FIN46(R)-8 -Paragraph C6 -Subparagraph c false 17 Discounted Lease Payments, net 2 fe_VariableInterestEntitiesDiscountedLeasePaymentsNet fe false debit instant Discounted Lease Payments, net. false false false false false false false false false false false verboselabel false 1 false true false false 1185000000 1185000000 [1] 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:monetaryItemType monetary Discounted Lease Payments, net. No authoritative reference available. false 18 Variable Interest Entities Net Exposure 2 fe_VariableInterestEntitiesNetExposure fe false credit instant Variable Interest Entities Net Exposure. false false false false false false false false false false false verboselabel false 1 false true false false 191000000 191000000 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:monetaryItemType monetary Variable Interest Entities Net Exposure. No authoritative reference available. false 27 CEI [Member] 0 na true na na No definition available. false true false false false false false false false false false http://firstenergycorp.com/role/disclosurevariableinterestentitiesdetails 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 false 6 USD true false false false CEI [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_SubsidiaryTwoMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ na No definition available. No authoritative reference available. false 28 Net exposure to loss based upon the casualty value provisions 2 fe_NetExposureToLossBasedUponCasualtyValueProvisionsAbstract fe false na duration Net exposure to loss based upon casualty value provisions. 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 Net exposure to loss based upon casualty value provisions. false 29 Maximum Exposure 2 us-gaap_VariableInterestMaximumExposureToLoss us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 627000000 627000000 [2] 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:monetaryItemType monetary Quantifies the entity's maximum exposure to loss. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number FAS140-4 and FIN46(R)-8 -Paragraph C6 -Subparagraph c false 30 Discounted Lease Payments, net 2 fe_VariableInterestEntitiesDiscountedLeasePaymentsNet fe false debit instant Discounted Lease Payments, net. false false false false false false false false false false false verboselabel false 1 false true false false 71000000 71000000 [1],[2] 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:monetaryItemType monetary Discounted Lease Payments, net. No authoritative reference available. false 31 Variable Interest Entities Net Exposure 2 fe_VariableInterestEntitiesNetExposure fe false credit instant Variable Interest Entities Net Exposure. false false false false false false false false false false false verboselabel false 1 false true false false 556000000 556000000 [2] 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:monetaryItemType monetary Variable Interest Entities Net Exposure. No authoritative reference available. false 40 TE [Member] 0 na true na na No definition available. false true false false false false false false false false false http://firstenergycorp.com/role/disclosurevariableinterestentitiesdetails 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 false 7 USD true false false false TE [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_SubsidiaryThreeMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ na No definition available. No authoritative reference available. false 41 Net exposure to loss based upon the casualty value provisions 2 fe_NetExposureToLossBasedUponCasualtyValueProvisionsAbstract fe false na duration Net exposure to loss based upon casualty value provisions. 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 Net exposure to loss based upon casualty value provisions. false 42 Maximum Exposure 2 us-gaap_VariableInterestMaximumExposureToLoss us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 627000000 627000000 [2] 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:monetaryItemType monetary Quantifies the entity's maximum exposure to loss. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number FAS140-4 and FIN46(R)-8 -Paragraph C6 -Subparagraph c false 43 Discounted Lease Payments, net 2 fe_VariableInterestEntitiesDiscountedLeasePaymentsNet fe false debit instant Discounted Lease Payments, net. false false false false false false false false false false false verboselabel false 1 false true false false 346000000 346000000 [1],[2] 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:monetaryItemType monetary Discounted Lease Payments, net. No authoritative reference available. false 44 Variable Interest Entities Net Exposure 2 fe_VariableInterestEntitiesNetExposure fe false credit instant Variable Interest Entities Net Exposure. false false false false false false false false false false false verboselabel false 1 false true false false 281000000 281000000 [2] 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:monetaryItemType monetary Variable Interest Entities Net Exposure. No authoritative reference available. false 53 OE [Member] 0 na true na na No definition available. false true false false false false false false false false false http://firstenergycorp.com/role/disclosurevariableinterestentitiesdetails 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 false 8 USD true false false false OE [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_SubsidiaryOneMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ na No definition available. No authoritative reference available. false 54 Net exposure to loss based upon the casualty value provisions 2 fe_NetExposureToLossBasedUponCasualtyValueProvisionsAbstract fe false na duration Net exposure to loss based upon casualty value provisions. 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 Net exposure to loss based upon casualty value provisions. false 55 Maximum Exposure 2 us-gaap_VariableInterestMaximumExposureToLoss us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 672000000 672000000 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:monetaryItemType monetary Quantifies the entity's maximum exposure to loss. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number FAS140-4 and FIN46(R)-8 -Paragraph C6 -Subparagraph c false 56 Discounted Lease Payments, net 2 fe_VariableInterestEntitiesDiscountedLeasePaymentsNet fe false debit instant Discounted Lease Payments, net. false false false false false false false false false false false verboselabel false 1 false true false false 511000000 511000000 [1] 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:monetaryItemType monetary Discounted Lease Payments, net. No authoritative reference available. false 57 Variable Interest Entities Net Exposure 2 fe_VariableInterestEntitiesNetExposure fe false credit instant Variable Interest Entities Net Exposure. false false false false false false false false false false false verboselabel false 1 true true false false 161000000 161000000 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:monetaryItemType monetary Variable Interest Entities Net Exposure. No authoritative reference available. false 1 The net present value of FirstEnergy's consolidated sale and leaseback operating lease commitments is $1.7 billion. 2 CEI and TE are jointly and severally liable for the maximum loss amounts under certain sale-leaseback agreements. 4 28 false NoRounding UnKnown UnKnown false true