Deferral of regulatory assetDeferral of new regulatory assetsDeferral of new regulatory assetsDeferral Of Regulatory Asset.Other Income Expense AbstractOTHER INCOME (EXPENSE):Other Income Expense Abstract.Deferred Charges And Other Assets AbstractDEFERRED CHARGES AND OTHER ASSETS:Deferred Charges And Other Assets Abstract.Liabilities And Capitalization AbstractLIABILITIES AND CAPITALIZATIONLiabilities And Capitalization Abstract.Total CapitalizationTotal capitalizationTotal Capitalization.Net Plant Excluding Construction Work In ProgressTotal in service, net of accumulated depreciationNet Plant Excluding Construction Work In Progress.New Financing [Abstract]New Financing-New Financing Abstract.Redemptions And Repayments [Abstract]Redemptions and Repayments-Redemptions and Repayments-Redemptions And Repayments Abstract.Cash Collateral NetCash collateral received (paid), netCash Collateral Net.Deferred rents and lease market valuation liabilityDeferred Rents And Lease Market Valuation Liability.Deferred rents and lease market valuation liabilityDeferred rents and lease market valuation liabilityOther Comprehensive Income Loss Abstract.Other Comprehensive Income Loss AbstractOTHER COMPREHENSIVE INCOME:Document and Entity Information [Abstract]Document and Entity Information Abstract.Earnings Per Share Tables.Earnings Per Share (Tables) [Abstract]Reconciliation of Basic and Diluted Earnings per Share Text BlockReconciliation of Basic and Diluted Earnings per Share of Common StockReconciliation of Basic and Diluted Earnings per Share. .Earnings Per Share Details.Earnings Per Share (Details) [Abstract]Recognized tax benefits.Recognized tax benefitsRecognized tax benefitsTax benefits favorably affecting effective tax rate.Tax benefits affecting effective tax rateTax benefits favorably affecting effective tax rateAdjusted accumulated deferred income taxes.Adjusted accumulated deferred income taxesAdjusted accumulated deferred income taxesRepair deduction cost.Repair deduction costRepair deduction costAdjusted goodwill.Adjusted goodwillAdjusted goodwillDerivatives and Hedging Topic policy [Text Block]Derivatives and Hedging Topic [Text Block]Derivatives and Hedging Topic policy Text Block.New Accounting Standards and Interpretations (Policies) [Abstract]New Accounting Standards And Interpretations Policies.Income Taxes Details.Income Taxes (Details) [Abstract]Income Taxes Textuals AbstractIncome Taxes (Textuals) [Abstract]Income Taxes Textuals.Organization and Basis of Presentation [Abstract]Organization And Basis Of Presentation Abstract.Goodwill Abstract.Goodwill [Abstract]Fair Value Measures [Abstract]Fair Value Measures Abstract.Derivative Instruments Abstract.Derivative Instruments [Abstract]Pension And Other Postretirement Benefits Abstract.Pension and Other Postretirement Benefits [Abstract]Variable Interest Entities [Abstract]Variable Interest Entities Abstract.Income Taxes [Abstract]Income Taxes Abstract.Commitments, Guarantees and Contingencies [Abstract]Commitments Guarantees And Contingencies Abstract.Regulatory Matters [Abstract]Regulatory Matters Abstract.Segment Information Abstract.Segment Information [Abstract]Pension and Other Postretirement Benefits.Pension and Other Postretirement Benefits (Tables) [Abstract]Pension benefit costs (including amounts capitalized).Pension Benefit Costs Including Amounts Capitalized Text BlockPension benefit costs (including amounts capitalized)Other postretirement benefit costs (including amounts capitalized).Other Postretirement Benefit Costs Including Amounts Capitalized Text BlockOther postretirement benefit costs (including amounts capitalized)Periodic Pension Costs Allocated To Parent And Subsidairies Text BlockPeriodic pension costs (including amounts capitalized)Periodic pension costs allocated to parent and subsidairies.Periodic Postretirement Benefit Costs Allocated To Parent And Subsidairies Text BlockPeriodic postretirement benefit costs (including amounts capitalized)Periodic postretirement benefit costs allocated to parent and subsidairies.Pension and Other Postretirement Benefits.Pension and Other Postretirement Benefits (Details) [Abstract]Penelec [Member]Subsidiary Six.Met-Ed [Member]Subsidiary Five.JCP&L [Member]Subsidiary Four.TE [Member]Subsidiary Three.CEI [Member]Subsidiary Two.Other Subsidiaries.Other Subsidiaries [Member]Pension benefit costs (including amounts capitalized).Pension Benefit Costs Including Amounts Capitalized AbstractPension benefit costs (including amounts capitalized)Pension Benefits.Pension Benefits AbstractPension BenefitsOther postretirement benefit costs (including amounts capitalized).Other Postretirement Benefit Costs Including Amounts Capitalized AbstractOther postretirement benefit costs (including amounts capitalized)Other Postretirement Benefits.Other Postretirement Benefits AbstractOther Postretirement BenefitsPeriodic Pension Costs Allocated To Parent And Subsidairies AbstractPeriodic pension costs (including amounts capitalized)Periodic pension costs allocated to parent and subsidairies.Pension Benefit Cost (Credit).Pension Benefit Cost Credit AbstractPension Benefit Cost (Credit)Periodic postretirement benefit costs (including amounts capitalized).Periodic Postretirement Benefit Costs Including Amounts Capitalized AbstractPeriodic postretirement benefit costs (including amounts capitalized)Other Postretirement Benefit Cost (Credit).Other Postretirement Benefit Cost Credit AbstractOther Postretirement Benefit Cost (Credit)Pension and Other Postretirement Benefits.Pension And Other Postretirement Benefits Textuals AbstractPension and Other Postretirement Benefits (Textuals)Plan amendment.Plan Amendment [Member]voluntary contribution.Voluntary Contribution [Member]Voluntary Enhanced Retirement Option.Voluntary Enhanced Retirement Option [Member]Commitments Guarantees and Contingencies.Commitments, Guarantees and Contingencies (Details) [Abstract]Commitments Guarantees And Contingencies Textuals AbstractCommitments, Guarantees and Contingencies (Textuals)Commitments Guarantees and Contingencies.Parental guarantees.Parental Guarantees [Member]Subsidiaries Guarantees [Member]Subsidiaries Guarantees [Member]Subsidiaries guarantees.Surety bonds and related guarantees.Surety Bonds And Related GuaranteesSurety bonds and related guaranteesOutstanding Collateral PaymentsOutstanding collateral payments included in other assetsOutstanding collateral payments.Change in forward prices first 12 months.Change In Forward Prices First YearFES change in forward prices first 12 monthsChange In Forward Prices After First YearFES change in forward prices thereafterChange in forward prices there afterSurplus Margin GuarantyNGC entered into a Surplus Margin GuarantySurplus Margin Guaranty.Undivided InterestPercentage sale and leaseback transaction for undivided interestUndivided interest.Penalties per day for violations under emissions regulations.Penalties Per Day For Violations Under Emissions RegulationsPenalties per day for violations under emissions regulationsReduction in utility plant NOX emissions from projected 2007 (In Percentage)Reduction In Utility Plant Nox EmissionsReduction in utility plant NOX emissions.Power Plants ComplaintsOther U.S. power plants complaintsPower plants complaints.Averaging period of interim enforcement policyAveraging period of interim enforcement policy (In Days)Averaging period of interim enforcement policy.Notice Letter RequiredNumber of days required prior to the filing of a citizen suit under noticeNotice letter, required.Cap And Trade Program To Reduce Mercury Emissions After One YearCap-and-trade program to reduce mercury emissions by 2010 (In Tons)Cap-and-trade program to reduce mercury emissions after one year.Cap And Trade Program To Reduce Mercury Emissions After Nine YearsCap-and-trade program to reduce mercury emissions by 2018 (In Tons)Cap-and-trade program to reduce mercury emissions after nine years.Environmental remediation accrued liabilities.Environmental Remediation Accrued LiabilitiesEnvironmental remediation accrued liabilitiesParental guarantee associated with the funding of decommissioning costs.Parental Guarantee Associated With The Funding Of Decommissioning CostsParental guarantee associated with the funding of decommissioning costsShortfall net value of the decommissioning trust fund.Shortfall Net Value Of The Decommissioning Trust FundShortfall net value of the decommissioning trust fundArbitration panel issued an opinion to award.Arbitration Panel Issued An Opinion To AwardArbitration panel issued an opinion to awardExpected Appeal processExpected Appeal process (In Months)Expected Appeal process.Liability For The Potential AwardLiability recognized for potential award in 2005 by JCP&LLiability for the potential award.Financings and energy related activities.Financings And Energy Related Activities [Member]Electricity production from renewable sources (In Percentage)Electricity production from renewable sources.Electricity Production From Renewable SourcesForward contracts and future priceForward Contracts And Future PriceFES forward contracts and future priceAfter four years.After Four Years [Member]After Fourty Two Years.After Fourty Two Years [Member]After Seventeen Years.After Seventeen Years [Member]Regulatory Matters.Regulatory Matters (Details) [Abstract]Regulatory Matters.Regulatory Matters Textuals AbstractRegulatory Matters (Textuals)Increase electric distribution rates.Increase Electric Distribution RatesIncrease electric distribution ratesNew Generation Rates For CustomersPeriod for New generation rates for customers beginning in 2009 (In Years)New Generation Rates For Customers.Regulatory Transition ChargeWrite off Regulatory Transition Charge balanceRegulatory Transition Charge.Winning Tranches AuctionWinning tranches auction (In Percentage)Winning tranches auction. (In percentage)Utilities Required To Reduce Peak DemandUtilities required to reduce peak demand in 2009 (In Percentage)Utilities required to reduce peak demand in 2009 in percentage.Renewable Energy Resources EquivalentElectric utilities and electric service companies are required to serve part of their load from renewable energy resources (In Percentage)Renewable energy resources equivalent in percentage.Electric Generation Service For Period BeginningOhio Companies filed an MRO to procure electric generation service for the period beginningElectric generation service for the period beginning.New TSC resulted in reduction of monthly billing (In Percentage)New Transmission Service ChargeNew Transmission Service Charge.Customer prepayments earn interest (In Percentage)Customer prepayments earn interest.Customer Prepayments Earn InterestMaximize energy efficiency to achieve reduction consumption by 2020 (In Percentage)Maximize Energy Efficiency To Achieve ConsumptionMaximize energy efficiency to achieve consumption.State electricity needs with renewable energy by 2020 (In Percentage)Renewable EnergyRenewable energy.Pricing for new transmission facilities that spreads of the cost of new 345 kV and higher transmission facilities (In Percentage)New Transmission Facilities CostNew transmission facilities cost.FES Power Supply Agreement with Ohio Companies to supply power for the period January 5, 2009 through March 31, 2009 (In Percentage)Power Supply Agreement For The Period Through Three MonthsPower Supply Agreement for the period three months.FES Power Supply Agreement with Ohio Companies to supply power for the period April 1, 2009 through May 31, 2009 (In Percentage)Power Supply Agreement For The Period Through One MonthPower Supply Agreement for the period one month.Excess Congestion Expenses And Marginal LossesReimburse of congestion expenses and marginal losses in excess of specified limitExcess congestion expenses and marginal losses.Material Adverse Event.Material Adverse Event [Member]Below Investment Grade Credit Rating [Member]Below Investment Grade Credit Rating.Projected Transmission CostTransmission cost projectionsProjected Transmission Cost.Deferred Projected Cost.Deferred Projected CostDeferred projected costDeferred accumulated cost, total.Deferred Accumulated Cost TotalDeferred accumulated cost, totalInfrastructure and energy projects.Infrastructure And Energy ProjectsInfrastructure and energy projectsCurrent program.Current Program [Member]Transformerand capicitor.Transformerand Capicitor [Member]Existing program.Existing Program [Member]Transformerand distibutionline.Transformerand Distibutionline [Member]JCP&L former owning in Keystone Station and Penelec (In Percentage)Former Ownership Of Subsidiary In Work UnitFormer ownership of Subsidiary in Work Unit.Capping Of Gas One EmissionsCapping of SO2 emissions (In Tons)Capping of SO2 emissions.Capping of Gas Two emissionsCapping of NOx emissions (In Tons)Capping of NOx emissions.Uppper threshold limit for carbon di oxide emissionUppper threshold limit for carbon di oxide emission (Tons per Year)Uppper threshold limit for carbon di oxide emission.Lower threshold limit for carbon di oxide emission (Tons per Year).Lower threshold limit for carbon di oxide emissionLower threshold limit for carbon di oxide emission (Tons per Year)Average winning bid price equivalent to a retail rate (Per KWH)Average Winning Bid Price Equivalent To Retail Rate.Average Winning Bid Price Equivalent To Retail RateDelivery service improvement rider at an overall average rate (Per KWH)Delivery service improvement rider at an overall average rate.Delivery service improvement rider at an overall average ratePrincipal Amount plus carrying charges of deferrals.Principal Amount plus carrying charges of deferralsPrincipal Amount plus carrying charges of deferralsTime required for collection of deferrals amount.Time required for collection of deferrals amountTime required for collection of deferrals amount from September 2009Recovery of deferral from residential customers.Recovery of deferral from residential customersRecovery of deferral from residential customersRecovery of deferral from non residential customers.Recovery of deferral from non residential customersRecovery of deferral from non-residential customersWeighted Average Wholesale Price For Generation And TransmissionWeighted average wholesale price for generation and transmission (Per KWH)Weighted average wholesale price for generation and transmission (dollar per KWH).Percentage of load supply per tranchePercentage of load supply per tranchePercentage of load supply per trancheTotal annual energy savings.Total annual energy savingsTotal annual energy savingsReview period began after the rule filed with the Joint Committee on Agency Rule Review ( In Days)Review period began after the rule filed with the Joint Committee on Agency Rule Review.Review period began after the rule filed with the Joint Committee on Agency Rule ReviewDefer of projected cost to future TscOrder And Deferred Projected Cost.Order And Deferred Projected CostUtilities must provide for the installation of smart meter technology (In Years)Utilities must provide for the installation of smart meter technology.Utilities must provide for the installation of smart meter technologyMinimum reduction in Utilities peak demand (In Percentage)Minimum reduction in Utilities peak demand.Minimum reduction in Utilities peak demandMinimum reduction in Utilities reduce energy consumption (In Percentage)Minimum reduction in Utilities reduce energy consumption.Minimum reduction in Utilities reduce energy consumptionIncrease in monthly bill of customer (In Percentage)Increase in monthly bill of customer.Increase in monthly bill of customerAdditional annual generation revenue.Additional annual generation revenueAdditional annual generation revenuePPUC Provided For Additional Comment PeriodPPUC provided for an additional comment period (In Days)PPUC provided for an additional comment period in Days.Updated estimated decommissioning costs.Updated estimated decommissioning costsUpdated estimated decommissioning costsPreviously estimated decommissioning costs.Previously estimated decommissioning costsPreviously estimated decommissioning costsReduce Peak Demand For ElectricityReduce peak demand for electricity by 2020 (In MW)Reduce peak demand for electricity in MW.Voltage Transmission Facilities And Zonal Transmission RateVoltage transmission facilities across PJM and a zonal transmission rate (In KV)Voltage transmission facilities and zonal transmission rate in KV.New Voltage transmission facilities across PJM and a zonal transmission rate (In KV)New Voltage transmission facilities and zonal transmission rate.New Voltage transmission facilities zonal transmission ratePurchased additional tranches from other bidders.Purchased additional tranches from other biddersPurchased additional tranches from other biddersWeighted average wholesale price for generation and transmission (Per KWH)Weighted average price for generation and transmission.Weighted average price for generation and transmissionIncreased sale price of power.Increased sale price of powerIncreased sale prices of powerEnergy resources required to be supplied by FES (In MW)Energy resources required.Energy resources requiredEnergy purchases by subsidiaries.Energy purchases by subsidiariesEnergy purchases by subsidiaries (In MW)Normal Condition.Normal Condition [Member]Stress Condition.Stress Condition [Member]Variable Interest Entities.Variable Interest Entities (Tables) [Abstract]Variable Interest Entities.Variable Interest Entities (Details) [Abstract]Net exposure to loss based upon the casualty value provisions.Net exposure to loss based upon the casualty value provisions AbstractNet exposure to loss based upon the casualty value provisionsDiscounted Lease Payments, net.Variable interest entities discounted lease payments netDiscounted Lease Payments, netVariable Interest Entities Net Exposure.Variable Interest Entities Net ExposureVariable Interest Entities Net ExposurePurchased power costs from entities AbstractPurchased power costs from entities:Purchased power costs from entities.Net exposure to loss based upon the casualty value provisions.Net exposure to loss based upon the casualty value provisions Text BlockNet exposure to loss based upon the casualty value provisionsSegment Information.Segment Information (Tables) [Abstract]Segment Information.Segment Information (Details) [Abstract]Segment Financial Information.Segment Financial Information AbstractSegment Financial InformationOther Business Operations.Other Business Operations [Member]Competitive Energy Services [Member]Segment Two.Segment One.Energy Delivery Services [Member]Reconciling Adjustments.Reconciling Adjustments [Member]Variable Interest Entities.Variable Interest Entities Textuals AbstractVariable Interest Entities (Textuals) [Abstract]Variable interest entities distributions to owners.Variable Interest Entities Distributions to ownersDistributions to ownersVariable interest entities acquisition of additional interest in joint ventures.Variable Interest Entities Acquisition of additional interest in joint venturesAcquisition of additional interest in joint venturesVariable interest entities percentage of mining operations acquired by joint venturePercentage of mining operations acquired by joint ventureVariable interest entities percentage of mining operations acquired by joint venture.Variable interest entities Percentage of transportation operations acquired by joint venturePercentage of transportation operations acquired by joint ventureVariable interest entities percentage of transportation operations acquired by joint venture.Variable interest entities economic interest of entity one in joint venture.Variable interest entities economic interest of entity one in joint ventureEconomic interest of FEV in joint ventureVariable interest entities economic interest of entity two in joint ventureEconomic interest of an affiliate of the Boich Companies in joint ventureVariable interest entities economic interest of entity two in joint venture.Variable interest entities Amount agreed to be paid by entity one to entity two for purchase of an additional economic interestAmount agreed to be paid by FEV to affiliates of the Boich Companies for purchase of an additional economic interestVariable interest entities amount agreed to be paid by entity one to entity two for purchase of an additional economic interest.Percentage of additional economic interest purchased by entity onePercentage of additional economic interest purchased by FEV in the Signal Peak mining and coal transportation operationsPercentage of additional economic interest purchased by entity one.Percentage of remaining stake acquired by joint venture in the mining operations.Percentage of remaining stake acquired by joint venture in the mining operationsPercentage of remaining stake acquired by joint venture in the mining operationsDuration of note issued by joint ventureDuration of note issued by joint venture.Duration of note issued by joint venture (in years)Variable interest entities Percentage of equity interest by an unaffiliated third party included in Ownership of entity threePercentage of equity interest by an unaffiliated third party included in ownership of PNBVVariable interest entities Percentage of equity interest by an unaffiliated third party included in Ownership of entity three.Variable interest entities net present value of parent company consolidated sale and leaseback operating lease commitmentsNet present value of FirstEnergy's consolidated sale and leaseback operating lease commitmentsVariable interest entities net present value of parent company consolidated sale and leaseback operating lease commitments.Lessor Equity Interests Purchased By Subsidiary One In Subsidiary Two Sale And Leaseback Of PlantLessor equity interests purchased by NGC in the OE sale and leaseback of the Perry Plant (MW)Lessor equity interests purchased by subsidiary one in subsidiary two sale and leaseback of the plant.Lessor Equity Interests Purchased By Subsidiary One In Subsidiary Two Sale And LeasebackLessor equity interests purchased by NGC in the OE sale and leaseback of Beaver Valley Unit 2 (MW)Lessor equity interests purchased by subsidiary one in subsidiary two sale and leaseback.Lessor Equity Interests Purchased By Subsidiary One In Subsidiary Three And Four Sale And LeasebackLessor equity interests purchased by NGC in the TE and CEI sale and leaseback of Beaver Valley Unit 2 (MW)Lessor equity interests purchased by subsidiary one in the subsidiary three and four sale and leaseback.Number of long term power purchase agreements maintained by parent company with Non utility generation entitiesNumber of long-term power purchase agreements maintained by FirstEnergy with NUG entitiesNumber of long term power purchase agreements maintained by parent company with Non utility generation entities.Transition bonds sold to securitize the recovery of subsidiary five bondable stranded costs amountTransition bonds sold to securitize the recovery of JCP&L's bondable stranded costs associated with the divested Oyster Creek Nuclear Generating StationTransition bonds sold to securitize the recovery of subsidiary five bondable stranded costs, amount.Entitlement of subsidiary five to aggregate quarterly servicing fees payable from Transition bond charge collectionsEntitlement of JCP&L to aggregate quarterly servicing fees, payable from TBC collectionsEntitlement of subsidiary five to aggregate quarterly servicing fees payable from Transition bond charge collections.Segment Information.Segment Information Textuals AbstractSegment Information (Textuals)Number of reportable operating segments.Number of reportable operating segmentsNumber of reportable operating segmentsIssuance Of Notes In Connection With Joint Venture AcqusitionIssuance of notes in connection with joint venture acqusition, amountIssuance of notes in connection with joint venture acqusition.FirstEnergy Ventures Corp.FEV [Member]Variable Interest Entities Percentage Of Equity Interest Held By Wholly Owned Subsidiary Of Entity FourPercentage of equity interest held by OES Ventures, a wholly owned subsidiary of OEVariable Interest Entities Percentage Of Equity Interest Held By Wholly Owned Subsidiary Of Entity Four.FirstEnergy Solutions Corp.FES [Member]Fair Value of Financial Instruments.Fair Value of Financial Instruments (Details) [Abstract]Fair Value Assets Measured On Recurring BasisTotalFair Value Assets Measured On Recurring Basis.Fair Value Liabilities Measured On Recurring Basis.Fair Value Liabilities Measured On Recurring BasisTotalFair Value of Financial Instruments.Fair Value of Financial Instruments (Tables) [Abstract]Assets and Liabilities Measured on Recurring Basis.Assets and Liabilities Measured on Recurring Basis Text BlockAssets and Liabilities Measured on Recurring BasisFair value and related carrying amounts of long-term debt and other long-term obligations.Fair value and related carrying amounts of long term debt and other long term obligations Text BlockFair value and related carrying amounts of long-term debt and other long-term obligationsApproximate fair value and related carrying amounts of notes receivable.Approximate fair value and related carrying amounts of notes receivable Text BlockApproximate fair value and related carrying amounts of notes receivableProceeds from the sale of investments in available-for-sale securities, realized gains and losses on those sales, and interest and dividend income.Proceeds from the sale of investments in available for sale securities realized gains and losses on those sales and interest and dividend income Text BlockProceeds from the sale of investments in available-for-sale securities, realized gains and losses on those sales, and interest and dividend incomeFair Value of Financial Instruments.Fair Value of Financial Instruments Textuals AbstractFair Value of Financial Instruments (Textuals) [Abstract]Reconciliation of changes in the fair value of Nug contracts Text BlockReconciliation of changes in the fair value of NUG contractsReconciliation of changes in the fair value of Nug contracts.Investments not required to be disclosed.Investments not required to be disclosedInvestments not required to be disclosedInvestment excludes Receivables, Payables and Accrued incomeInvestments excludes Receivables, Payables and Accrued incomeInvestments excludes Receivables, Payables and Accrued income.Derivative Instruments.Derivative Instruments (Details) [Abstract]Derivative Instruments.Derivative Instruments (Tables) [Abstract]Fair value of commodity derivatives.Fair value of commodity derivatives Text BlockFair value of commodity derivativesNoncurrent Liabilities Member.Noncurrent Liabilities [Member]Purchases in (MWH, Gallons, mmBtu)Volume Of Derivatives Purchases.Volume Of Derivatives PurchasesSales in (MWH, Gallons, mmBtu)Volume Of Derivatives Sales.Volume Of Derivatives SalesNet in (MWH, Gallons, mmBtu)Volume Of Derivatives Net.Volume Of Derivatives NetVolume Of Parent Companys Outstanding Derivative Transactions Text BlockVolume of First Energy's outstanding derivative transactionsVolume Of Parent Company's Outstanding Derivative Transactions.Purchased Power Expense Member.Purchased Power Expense [Member]Fuel Expense Member.Fuel Expense [Member]The effects of interest rate derivatives on the consolidated statements of income and comprehensive income.The effects of interest rate derivatives on the consolidated statements of income and comprehensive income AbstractThe effects of interest rate derivatives on the consolidated statements of income and comprehensive incomeRegulatory Assets Member.Regulatory Assets [Member]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.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 AbstractThe effect of derivative instruments on the statements of income and comprehensive income for instruments designated in cash flow hedging relationships and not in hedging relationshipsVolume Of Parent Companys Outstanding Derivative Transaction AbstractVolume of First Energy's outstanding derivative transactionsVolume Of Parent Companys Outstanding Derivative Transaction.Derivative Instruments.Derivative Instruments Textuals AbstractDerivative Instruments (Textuals) [Abstract]First Energy terminated forward swaps with a notional valueNotional Value of Terminated Forward SwapsNotional value of Terminated forward swaps.Unamortized losses associated with prior interest rate hedgesUnamortized losses included in AOCL associated with prior interest rate hedgesUnamortized losses associated with prior interest rate hedges.Unamortized losses associated with prior interest rate hedges net of tax.Unamortized losses associated with prior interest rate hedges net of taxUnamortized losses associated with prior interest rate hedges net of taxUnamortized losses included in Aocl associated with commodity derivativesTotal unamortized losses included in AOCL associated with commodity derivativesunamortized losses included in AOCL associated with commodity derivativesunamortized losses included in AOCL associated with commodity derivatives.Total unamortized losses included in AOCL associated with commodity derivatives, Net of tax.Total unamortized losses included in Aocl associated with commodity derivatives Net of taxTotal unamortized losses included in AOCL associated with commodity derivatives, Net of taxChange resulted from decrease related to current hedging activity, Net of tax.Change resulted from decrease related to current hedging activity Net of taxChange resulted from decrease related to current hedging activity, Net of taxDecrease due to net hedge losses reclassified to earnings.Decrease due to net hedge losses reclassified to earningsDecrease due to net hedge losses reclassified to earningslong-term debt and other long-term obligations.long term debt and other long term obligationslong-term debt and other long-term obligationsFair value and related carrying amounts of long-term debt and other long-term obligations.Fair value and related carrying amounts of long term debt and other long term obligations AbstractFair value and related carrying amounts of long-term debt and other long-term obligationsOther Investments.Other Investments [Member]Cash balance exculded from available for sale securities.Cash balance exculded from available for sale securitiesCash balance exculded from available for sale securitiesFair value of government obligations.Fair value of government obligations [Member]Current Assets [Member]Current assets.Current Liabilities.Current Liabilities [Member]Power Purchase Contract Asset [Member]Power purchase contract asset.Power Purchase Contract Liabilities [Member]Power purchase contract liabilities.Derivative Instruments Gain (Loss), Net, ReclassifiedDerivative instruments gain loss net reclassified.Realized Gain (Loss) Reclassified to:Net deferred losses on derivative instruments in accumulated other comprehensive losses after tax to be reclassified to earningsNet deferred losses on derivative instruments in accumulated other comprehensive losses after tax to be reclassified to earnings.Net deferred losses on derivative instruments in accumulated other comprehensive losses after tax to be reclassified to earningsDerivative Credit Risk Related Contingent Features.Derivative Credit Risk Related Contingent Features [Member]Losses to be amortized to interest expenses during next tweleve monthsLosses to be amortized to interest expenses during next twelve monthsLosses to be amortized to interest expenses during next tweleve months.Intangible Assets.Intangible Assets (Details) [Abstract]Intangible Assets.Intangible Assets Textuals AbstractIntangible Assets (Textuals) [Abstract]Proposed Merger.Proposed Merger (Details) [Abstract]Proposed Merger.Proposed Merger Textuals AbstractProposed Merger With Allegheny Energy, Inc. (Textuals) [Abstract]Merger transactions costs Net of taxMerger transactions costs, net of taxMerger transactions costs, Net of tax.Consumer products Member.Consumer products [Member]Technology Member.Technology [Member]Utilities and energy Member.Utilities & energy [Member]Financial Member.Financial [Member]Right to receive portion of a share of common stock of parent companyPursuant to the Merger Agreement, Right to receive portion of a share of common stock of FirstEnergyRight to receive portion of a share of common stock of parent company.Portion Held By Stockholders Of Subsidiary Company In Combined EntityPortion held by stockholders of Allegheny Energy in combined entityPortion held by stockholders of subsidiary company in combined entityFair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Liabilities Net ValueEnding BalanceBeginning BalanceFair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Liabilities Net Value.Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Liabilities Net Purchases Sales Issuances SettlementsSettlementsFair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Liabilities Net Purchases Sales Issuances Settlements.Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Liabilities Net Unrealized Gains LossesUnrealized gains (losses)Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Liabilities Net Unrealized Gains Losses.Noncurrent Assets.Noncurrent Assets [Member]Fair value of interest rate swaps.Fair Value Of Interest Rate Swaps Text BlockFair value of interest rate swapsFair value of interest rate swaps.Fair Value Of Interest Rate Swaps AbstractFair value of interest rate swapsExpected Adverse Change In Quoted Market Prices Derivative InstrumentsExpected adverse change in quoted market prices of derivative instrumentsExpected adverse change in quoted market prices derivative instruments.Decrease net income due to adverse change in commodity prices.Decrease Net Income Due To Adverse Change In Commodity PricesDecrease net income due to adverse change in commodity pricesDecrease Net Income Due To Increase In Interest Rates Associated With Variable Rate DebtDecrease net income due to increase in interest rates associated with variable-rate debtDecrease net income due to increase in interest rates associated with variable-rate debt.Power purchase contract liability.Power Purchase Contract LiabilityPower purchase contract liabilityAccumulated Provision For Uncollectible Accounts OtherAccumulated provision for uncollectible accounts - otherAccumulated Provision For Uncollectible Accounts Other.Long Term Contract For Purchase Of Electric Power Cost IncurredPurchased power costs from entitiesLong Term Contract For Purchase of Electric Power Cost Incurred.Environmental Remediation Liabilities AccruedTotal environmental liabilitiesEnvironmental Remediation Liabilities Accrued.Utilities Required To Reduce Peak Demand From Two Thousand Ten To Two Thousand EighteenUtilities required to additional reduction in peak demand through 2018Utilities Required to Reduce Peak Demand From 2010 To 2018 in percentagePurchase of tranches by biddingPurchase of tranches by bidding.Purchase of tranches by biddingTransition bonds sold to securitize the recovery of deferred costs associated with JCP&L's supply of BGSInitial Bgs Transition BondsTransition bonds sold to securitize the recovery of deferred costs associated with subsidiary five supply of basic generation service.Guarantees And Surety Bonds ContractsOutstanding collateral paymentsGuarantees and Surety Bonds Contracts.Supplemental Guarantor Information (Details) [Abstract]Supplemental Guarantor Information Details AbstractMiscellaneousIncomeExpenseAbstractMiscellaneous income (expense), includingMiscellaneous income expense Abstact.InterestAndDebtExpenseAffiliatesInterest expense to affiliatesInterest expense to affiliatesInterest expense to affiliatesNGC [Member]Non Guarantor Subsidiaries Two MemberConsolidated [Member]Fes Consolidated.Investment in associated companiesInvestment in associated companies.Investment in associated companiesParent And Guarantor Member.Parent and Guarantor [Member]Property taxes.Property taxesProperty taxesUnamortized sale and leaseback costs.Unamortized sale and leaseback costsUnamortized sale and leaseback costsProperty taxes.Property taxes noncurrent liabilitiesProperty taxesSupplemental Guarantor Information Textuals AbstractSupplemental Guarantor Information.Supplemental Guarantor Infromation (Textuals) [Abstract]Sale And Leaseback Transactions Of Undivided InterestSale and leaseback transactions of undivided interest.Sale and leaseback transactions of undivided interest in Bruce MansfieldAffiliates MemberAffiliates MemberAffiliates [Member]Nonaffiliates MemberNonAffiliates Member.Non Affiliates MemberOE [Member]Subsidiary One Member.Heating Oil Futures [Member]Heating Oil Futures Member.Multiple Fixed For Floating Interest Rate Swap [Member]Multiple Fixed-For-Floating Interest Rate Swap.Non Utility Generation Contracts Member.Nonutility Generation Contracts [Member]NUG Contracts [Member]Total Assets [Member]Total Assets Member.Total Liabilities [Member]Total Liabilities Member.Cash Flow Hedges [Member]Cash Flow Hedges Member.Economic Hedges [Member]Economic Hedges Member.Nuclear Decommissioning Trust Investments [Member]Nuclear Decommissioning Trust Investments Member.Rabbi Trust Investments [Member]Rabbi Trust Investments Member.Nuclear Fuel Disposal Trust InvestmentsNuclear Fuel Disposal Trust Investments Member.NUG Trust Investments [Member]NUG Trust Investments Member.Other Securities [Member]Other Securities Member.Major Types Of Debt Securities [Axis]Major Types Of Debt Securities Axis.NUG Contract [Member]NUG Contract Member.Asset Retirement Obligations (Details) [Abstract]Asset Retirement Obligations.Asset Retirement Obligations Textuals AbstractAsset Retirement Obligations.Asset Retirement Obligations (Textuals)Supplemental Guarantor Information AbstractSupplemental Guarantor Information Abstract.Supplemental Guarantor Information Disclosure Text BlockSupplemental Guarantor Information Disclosure Text Block.Supplemental Guarantor Information (Tables) [Abstract]Supplemental Guarantor Information.FirstEnergy Solutions Corp Condensed Consolidating Statements Of Income Text BlockFirstEnergy Solutions Corp Condensed Consolidating Statements of Income.FirstEnergy Solutions Corp Condensed Consolidating Statements Of IncomeFirstEnergy Solutions Corp Condensed Consolidating Balance Sheets Text BlockFirstEnergy Solutions Corp Condensed Consolidating Balance Sheets Text Block.FirstEnergy Solutions Corp Condensed Consolidating Balance SheetsFirstEnergy Solutions Corp Condensed Consolidating Statements Of Cash Flows Text BlockFirstEnergy Solutions Corp Condensed Consolidating Statements Of Cash Flows.FirstEnergy Solutions Corp Condensed Consolidating Statements Of Cash FlowsGain Loss On DerivativesThe gains and losses from increase (decrease) in fair value of dervatives included in earnings.Commodity derivative transactions, netLeasehold improvement payments to associated companiesLeasehold improvement payments to associated companies.Leasehold improvement payments to associated companiesOutstanding guarantees related to energy and energy related contractsOutstanding guarantees related to energy and energy related contracts.Acceleration Of Payment [Member]Acceleration Of Payment.Additional collateral payments on parental guaranteesAdditional collateral payments on parental guarantees.Additional FES collateral paymentsAdditional FES collateral payments.Percent change in confidence level over one yearPercent change in confidence level over one year.Surety bonds and lines of creditSurety bonds and lines of credit.Net of tax decrease due to adverse change in commodity pricesNet of tax decrease due to adverse change in commodity prices.Hypothetical increase in the interest ratesHypothetical increase in the interest rates.Cash proceeds received of May terminationCash proceeds received of May termination.Accrued interest allocation for May terminationAccrued interest allocation for May termination.June fixed-for-floating interest rateswap agreements execution notional amountJune fixed-for-floating interest rateswap agreements execution notional amount.Debt underlying the June fixed for floating interest rate swap agreements executionDebt underlying the June fixed-for-floating interest rate swap agreements execution.Debt underlying the June fixed-for-floating interest rate swap agreements executionJuly notional amount of terminated fixed-for-floating interest rate swap agreementsJuly notional amount of terminated fixed-for-floating interest rate swap agreements.Cash proceeds received of July terminationCash proceeds received of July termination.Net of tax change increase related to current hedging activityNet of tax change increase related to current hedging activity.Collateral has been posted related to fair value of credit related contingent featuresCollateral has been posted related to fair value of credit related contingent features.Funds provided over the next three yearsFunds provided over the next three years.Funds provided by 2020Funds provided by 2020.Control drive mechanism requiring modificationControl drive mechanism requiring modification.Additional contribution to trustAdditional contribution to trust.Reduced parental guaranteeReduced parental guarantee.Protection system relays in able to validate maintenance recordsProtection system relays in able to validate maintenance records.Total protection system relaysTotal protection system relays.Generation discount to certain low income customersGeneration discount to certain low income customers.Recovery of marginal transmission lossesRecovery of marginal transmission losses.Capping of gas one emissions under CATRCapping of SO2 emissions under Clean Air Transport Rules.Capping of SO2 emissions under CATRProposed GHG emissions reduction by 2050Proposed greenhouse gas emissions reduction by 2050.Weighted average fixed interest rate of interest of interest rate swapsWeighted average fixed interest rate of interest of interest rate swaps.Current weighted average variable rate of interest rate swapsCurrent weighted average variable rate of interest rate swaps.Accrued interest allocation for July terminationAccrued interest allocation for July termination.NDT interest and dividend incomeNDT interest and dividend income.Assessment period costsAssessment period costs.Underpayment by PJM 2007 - 2009Underpayment by PJM 2007 - 2009Underpayment by PJM 2005 - 2007Underpayment by PJM 2005 - 2007.Regulatory asset impairment related to ESPRegulatory asset impairment related to ESP.Costs avoided by customersCosts avoided by customers.Fund to assist low income customersFund to assist low income customers.Generation discount for low income customersGeneration discount for low income customers.PUCO review of MRO (In Days)PUCO review of MRO in days.Responsive comments (In Days)Responsive comments in days.Reply comments (In Days)Reply comments in days.Number of customers served by utility operating companiesNumber of customers served by utility operating companies.Number of square miles in service territories in Ohio Pennsylvania and New JerseyNumber of square miles in service territories in Ohio Pennsylvania and New Jersey.Number of generating facilities owned or leased by competitive segmentNumber of generating facilities owned or leased by competitive segment.Megawatts of net demonstrated capacity of competitive segmentMegawatts of net demonstrated capacity of competitive segment.Decrease in the amount recovered for the costs incurredDecrease in the amount recovered for the costs incurred.Regional allocation of costsRegional allocation of costs.Revised decommisioning costsRevised decommisioning costs.Effect of derivative instruments on statements of income and comprehensive income for instruments designated in cash flow hedging relationships text blockEffect of derivative instruments on statements of income and comprehensive income for instruments designated in cash flow hedging relationships text block.Effect of derivative instruments on statements of income and comprehensive income for instruments not in hedging relationships text blockffect of derivative instruments on statements of income and comprehensive income for instruments not in hedging relationships text block.Shareholder value at merger agreement dateShareholder value at merger agreement date.Shareholder value at effectiveness dateShareholder value at effectiveness date.Market flow generatorsMarket flow generators.Market flow PJM generatorsNet underpaymentsNet underpayments.Net underpayments from PJM to MISOBasis Of Presentation [TextBlock]Basis Of Presentation TextBlock.Consolidation Of Subsidiaries [TextBlock]Consolidation Of Subsidiaries Text Block.Amendment FlagCurrent Fiscal Year End DateDocument Period End DateEntity [Domain]Entity Well Known Seasoned IssuerEntity Voluntary FilersEntity Current Reporting StatusEntity Filer CategoryEntity Public FloatEntity Registrant NameEntity Central Index KeyEntity Common Stock Shares OutstandingDocument Fiscal Year FocusDocument Fiscal Period FocusLegal Entity [Axis]Document TypeCustomers (less allowance of $33 million in 2010 and 2009)Accounts Receivable Net CurrentCustomersAccounts Receivable, Net, Current, TotalAccumulated other comprehensive lossAccumulated Other Comprehensive Income Loss Net Of TaxLess - Accumulated provision for depreciationAccumulated Depreciation Depletion And Amortization Property Plant And EquipmentAccumulated Depreciation Depletion And Amortization Property Plant And Equipment, Ending BalanceAccumulated Depreciation Depletion And Amortization Property Plant And Equipment, Beginning BalanceOther paid-in capitalAdditional Paid In Capital Common StockProperty additionsProperty additionsPayments To Acquire Productive AssetsPayments To Acquire Productive Assets, TotalDeferred purchased power and other costsDeferred Purchased Power CostsGain Loss On Sale Of DerivativesInterest rate swap transactionsGain on asset salesGain Loss On Sale Of Other AssetsUnrealized Gain (Loss) Recognized in:Unrealized Gain Loss On DerivativesAccumulated provision for uncollectible accounts - customerAllowance For Doubtful Accounts Receivable CurrentNuclear fuel and lease amortizationOther Amortization Of Deferred ChargesAmortization of new regulatory assetsAmortization Of Regulatory AssetAsset Retirement Obligation AbstractAsset Retirement Obligation Disclosure Text BlockASSET RETIREMENT OBLIGATIONSAsset retirement obligation period increase decreaseAsset retirement obligationsAsset Retirement Obligations NoncurrentBalance Sheets Unaudited [Abstract]Condensed Consolidating Balance Sheets (Unaudited)Realized gains from the sale of securities held in the nuclear decommissioning trustRealized gainsAvailable For Sale Securities Gross Realized GainsRealized lossesAvailable For Sale Securities Gross Realized LossesProceeds from salesAvailable For Sale Securities Gross Realized Gains Losses Sale ProceedsBASIC EARNINGS PER SHARE OF COMMON STOCKBasic earnings per share of common stockEarnings Per Share BasicBonds MemberCash and cash equivalents at end of periodCash and cash equivalents at beginning of periodCash and cash equivalentsCash And Cash Equivalents At Carrying ValueCash and Cash Equivalents, at Carrying Value, TotalCash Flow Hedge Derivative AssetsCash Flow Hedge Derivative Instrument Assets At Fair ValueCash Flow Hedge Derivative LiabilitiesCash Flow Hedge Derivative Instrument Liabilities At Fair ValueNet controlled disbursement activityProceeds From Repayments Of Bank OverdraftsAccrued compensation and retirement benefitsIncrease Decrease In Employee Related LiabilitiesAccrued taxesIncrease Decrease In Accrued Income Taxes PayableAccrued interestIncrease Decrease In Interest Payable NetMaterials and suppliesIncrease Decrease In InventoriesDecrease (increase) in operating assets-Increase Decrease In Operating Assets AbstractIncrease (decrease) in operating liabilities-Increase Decrease In Operating Liabilities AbstractPrepayments and other current assetsIncrease Decrease In Prepaid ExpenseAccounts payableIncrease Decrease In Accounts Payable TradeCOMMITMENTS, GUARANTEES AND CONTINGENCIESCommitments And Contingencies Disclosure Text BlockPower purchase contract assetCommodity Contract Asset NoncurrentCommon stock, shares authorizedCommon Stock Shares AuthorizedCommon stock, shares outstandingCommon Stock Shares OutstandingCOMPREHENSIVE INCOME AVAILABLE TO FIRSTENERGY CORP.Comprehensive Income Net Of TaxConstruction work in progressConstruction In Progress GrossFair value of corporate debt [Member]Corporate debt securities [Member]FuelFuel CostsPurchased powerCost Of Purchased PowerTotal current liabilitiesLiabilities, CurrentCURRENT LIABILITIES:Liabilities Current AbstractCurrently payable long-term debtLong Term Debt And Capital Lease Obligations CurrentLong-term debt and other long-term obligationsLong-term debt and other long-term obligationsLong-term debt and other long-term obligationsLong Term Debt And Capital Lease ObligationsDebt Securities MemberNuclear plant decommissioning trustsDecommissioning Fund InvestmentsInvested in external trusts for decommissioning and environmental remediationDecommissioning Trust Assets AmountDeferred Tax Assets Deferred IncomeAccumulated deferred income taxesAccumulated deferred income taxesDeferred Tax Liabilities NoncurrentDefined Benefit Plans DomainDerivative Name DomainDerivative By Nature AxisDerivative [Member]DERIVATIVE INSTRUMENTSDerivative Instruments And Hedging Activities Disclosure Text BlockOutstanding guarantees and other assurances aggregatedGuarantee Obligations Current Carrying ValueMaximum exposure under collateral provisionsGuarantee Obligations Maximum ExposureGuarantee Obligations Nature DomainGuarantee Obligations By Nature AxisDILUTED EARNINGS PER SHARE OF COMMON STOCKDiluted earnings per share of common stockEarnings Per Share DilutedTotal revenuesElectric RevenueRevenuesStock-based compensationShare Based CompensationCapital expenditures for environmental complianceEnvironmental Remediation ExpenseEquity investment in the joint venture by FEVEquity Method InvestmentsEquity Securities MemberExcise tax collectionsExcise And Sales TaxesDerivative AssetsFair Value Hedge Assets At Fair ValueFair Value Hedge Assets At Fair ValueDerivative LiabilitiesFair Value Hedge Liabilities At Fair ValueFair Value Hedge Liabilities At Fair ValueFinite Lived Intangible Assets AbstractAmortization expense (approximately)Finite Lived Intangible Assets Amortization ExpenseDebt securities issued by foreign governments [Member]Electricity Forwards [Member]Natural Gas Futures [Member]Gain in interest expense related to interest rate swapsGain Loss On Fair Value Hedges Recognized In EarningsLoss on debt redemptionGains Losses On Extinguishment Of DebtInvestment impairmentImpairment Of InvestmentsConsolidated Statements of Income (Unaudited) [Abstract]Condensed Consolidated Statements of Income (Unaudited)INCOME TAXESIncome Tax Disclosure Text BlockProceeds From (Payments for) Long-term Loans For Related PartiesLoans from associated companies, netRestricted funds for debt redemptionRestricted funds for debt redemptionIncrease Decrease In Restricted CashAssumed exercise of dilutive stock options and awardsIncremental Common Shares Attributable To Share Based Payment ArrangementsNet intangible assets included in other assets on the FirstEnergy Consolidated Balance SheetCustomer intangiblesGoodwillGoodwillGoodwill, Ending BalanceGoodwill, Beginning BalanceAccrued accumulated interestUnrecognized Tax Benefits Interest On Income Taxes AccruedInterest Rate Swap MemberMaterials and supplies, at average costInventory NetINVESTMENTS:Investments AbstractLetter Of Credit MemberTotal liabilities and capitalizationLiabilities And Stockholders EquityWeighted average fixed interest rate of debt securitiesLong Term Debt Percentage Bearing Fixed Interest RateWeighted average variable interest rate of debt securitiesLong Term Debt Percentage Bearing Variable Interest RateTotal investmentsLong Term InvestmentsFair ValueAvailable For Sale SecuritiesCost BasisHeld To Maturity SecuritiesInvestments in lease obligation bondsHeld To Maturity Securities NoncurrentNoncontrolling interestMinority InterestNet cash provided from (used for) financing activitiesNet Cash Provided By Used In Financing ActivitiesNet cash used for financing activitiesCASH FLOWS FROM FINANCING ACTIVITIES:Net Cash Provided By Used In Financing Activities AbstractNet cash used for investing activitiesNet Cash Provided by (Used in) Investing ActivitiesCASH FLOWS FROM INVESTING ACTIVITIES:Net Cash Provided By Used In Investing Activities AbstractNet cash provided from operating activitiesNet Cash Provided By Used In Operating ActivitiesNET CASH PROVIDED FROM (USED FOR) OPERATING ACTIVITIESCASH FLOWS FROM OPERATING ACTIVITIES:Net Cash Provided By Used In Operating Activities AbstractEARNINGS AVAILABLE TO FIRSTENERGY CORP.Earnings available to FirstEnergy Corp.Net Income LossNet change in cash and cash equivalentsCash And Cash Equivalents, Period Increase (Decrease)Cash And Cash Equivalents, Period Increase (Decrease), TotalNew Accounting Standards and Interpretations [Abstract]New Accounting Standards and Interpretations [Abstract]NEW ACCOUNTING STANDARDS AND INTERPRETATIONSSchedule Of New Accounting Pronouncements And Changes In Accounting Principles Text BlockTotal other income (expense)Total other expenseNonoperating Income ExpenseInterest expenseInterest expense - otherInterest And Debt ExpenseInterest and Debt Expense, TotalTotal deferred charges and other assetsAssets NoncurrentTotal noncurrent liabilitiesLiabilities NoncurrentNONCURRENT LIABILITIES:Liabilities Noncurrent AbstractNotes receivableNotes Receivable NetNotes Receivable, Related Parties, CurrentNotes Receivable from associated companiesNotional amount of interest rate swaps outstandingNotional Amount Of Interest Rate DerivativesOPERATING INCOMEOperating Income LossREVENUES:Revenues AbstractORGANIZATION AND BASIS OF PRESENTATIONOrganization Consolidation And Presentation Of Financial Statements Disclosure Text BlockOtherIncrease Decrease In Other Operating Capital NetChange in unrealized gain on available-for-sale securitiesOther Comprehensive Income Available For Sale Securities Adjustment Before Tax Period Increase DecreaseOther comprehensive incomeOther Comprehensive Income Loss Before Tax Period Increase DecreaseIncreased/Decreased AOCI before taxPension and other postretirement benefitsOther Comprehensive Income Defined Benefit Plans Adjustment Before Tax Period Increase DecreaseUnrealized gain on derivative hedgesOther Comprehensive Income Derivatives Qualifying As Hedges Before Tax Period Increase DecreaseOther comprehensive income, net of taxOther Comprehensive Income Loss Net Of Tax Period Increase DecreaseIncome tax expense related to other comprehensive incomeIncome tax expense (benefit) related to other comprehensive incomeOther Comprehensive Income Loss TaxOtherOther Assets CurrentPrepayments and otherOtherOtherPayments for (Proceeds from) Other Investing ActivitiesOtherOther Long Term InvestmentsOtherProceeds From (Payments For) Other Financing ActivitiesOther Postretirement Benefit Plans Defined Benefit MemberOther (less allowance of $7 million in 2010 and 2009)Other ReceivablesOtherCommon stock dividend paymentsCommon stock dividend paymentsPayments Of Dividends Common StockPension trust contributionPension ContributionsPension and OPEB expenses (benefits)Pension And Other Postretirement Benefit ExpensePENSION AND OTHER POSTRETIREMENT BENEFITSPension And Other Postretirement Benefits Disclosure Text BlockPension Plans Defined Benefit MemberRecognized net actuarial lossDefined Benefit Plan Actuarial Net Gains LossesAmortization of prior service costDefined Benefit Plan Amortization Of Prior Service Cost CreditPlan's discount rateDefined Benefit Plan Assumptions Used Calculating Benefit Obligation Discount RateExpected return on plan assetsDefined Benefit Plan Expected Return On Plan AssetsInterest costDefined Benefit Plan Interest CostPeriodic pension costs allocated to parent and subsidairiesNet periodic cost (credit)Periodic postretirement benefit costs allocated to parent and subsidairiesDefined Benefit Plan Net Periodic Benefit CostService costDefined Benefit Plan Service CostDefined Benefit Plans Disclosures Defined Benefit Plans AxisPrepaid taxesPrepaid TaxesLong-term debtProceeds From Issuance Of Long Term DebtProceeds From Issuance Of Long Term Debt, TotalSales of investment securities held in trustsProceeds From Sale Of Available For Sale SecuritiesProceeds From Sale Of Available For Sale Securities, TotalProceeds from asset salesProceeds from asset salesProceeds from asset salesShort-term borrowings, netProceeds From Short Term DebtProceeds From Short Term Debt, TotalIn serviceProperty Plant And Equipment GrossProperty, Plant and Equipment, Gross, Ending BalanceProperty, Plant and Equipment, Gross, Beginning BalanceProperty, Plant and Equipment, Gross, TotalTotal property, plant and equipmentProperty, Plant And Equipment, NetProperty, Plant and Equipment, Net, Ending BalanceProperty, Plant and Equipment, Net, Beginning BalanceReversal of accrued interest affecting effective tax rateTax Adjustments Settlements And Unusual ProvisionsREGULATORY MATTERSPublic Utilities Disclosure Text BlockPurchased power costs from entitiesSchedule Of Long Term Contracts For Purchase Of Electric Power Text BlockPurchases of investment securities held in trustsPurchases of investment securities held in trustsPayments To Acquire Available For Sale SecuritiesPayments to Acquire Available-for-sale Securities, TotalPayments To Acquire Intangible AssetsCustomer acquisition costsCustomer acquisition costsCash investmentsCash investmentsPayments For Proceeds From InvestmentsReceivablesReceivables Net Current [Abstract]Regulatory assetsRegulatory Assets NoncurrentLong-term debtLong-term debtRepayments Of Long Term DebtRepayments Of Long Term Debt, TotalShort-term borrowings, netShort-term borrowings, netRepayments Of Short Term DebtRepayments Of Short Term Debt, TotalReporting Segment [Domain]Retained earningsRetained Earnings Accumulated DeficitElectric utilitiesElectric Domestic Regulated RevenueUnregulated businessesElectric Worldwide Unregulated RevenueDeferred gain on sale and leaseback transactionSale Leaseback Transaction Deferred Gain NetGOODWILLSchedule Of Goodwill Text BlockSEGMENT INFORMATIONSegment Reporting Disclosure Text BlockSegment Financial InformationSchedule Of Segment Reporting Information By Segment Text BlockDepreciation and amortizationSegment Reporting Information Depreciation Depletion And Amortization ExpenseSegment Reporting Information Equity In Net Income Of Equity Method Investees Of Segmentnet income from equity investeesProperty additionsSegment Reporting Information Expenditures For Additions To Long Lived AssetsInternal revenuesInternal revenuesSegment Reporting Information Intersegment RevenueExternal revenuesSegment Reporting Information Revenue From External CustomersSegment Reporting Information, by Segment [Axis]Total revenuesSegment Reporting Segment RevenueShort Term Debt Type DomainShort Term Debt Type AxisShort-term borrowingsShort Term BorrowingsOtherShort Term Borrowings [Abstract]Short-term borrowings-Site Contingency Nature Of Contingency DomainSite Contingency By Nature AxisStatements of Cash Flows [Abstract]Consolidated Statements of Comprehensive Income (Unaudited) [Abstract]Common stockholders' equity-Stockholders Equity AbstractSwap MemberTotal current assetsAssets CurrentCURRENT ASSETS:Assets Current AbstractTransition bonds outstandingLong Term Transition BondUnrecognized tax benefits expected to resolved within the next twelve monthUnrecognized Tax BenefitsIncreased amount of unrecognized tax benefitsUnrecognized Tax Benefits Increases Resulting From Prior Period Tax PositionsUnrecognized benefits (if recognized) affecting effective tax rateUnrecognized Tax Benefits That Would Impact Effective Tax RateUtility Plant DomainVARIABLE INTEREST ENTITIESSchedule Of Variable Interest Entities Text BlockVoting interest of FEV and an affiliate of the Boich Companies in the joint ventureVariable Interest Entity Ownership PercentageWEIGHTED AVERAGE NUMBER OF DILUTED SHARES OUTSTANDINGAverage shares of common stock outstanding - DilutedWeighted Average Number Of Diluted Shares OutstandingWEIGHTED AVERAGE NUMBER OF BASIC SHARES OUTSTANDINGAverage shares of common stock outstanding - BasicWeighted Average Number Of Shares Outstanding BasicEliminations [Member]PROPERTY, PLANT AND EQUIPMENT:Property Plant And Equipment Net AbstractAmortized cost basis, unrealized gains and losses and fair values of investments in available-for-sale securitiesAvailable For Sale Securities Text BlockMajor Types Of Debt And Equity Securities DomainCost BasisAvailable For Sale Securities Amortized CostUnrealized GainsAvailable For Sale Securities Gross Unrealized GainsAmortized cost basis, unrealized gains and losses and fair values of investments in available-for-sale securitiesAvailable For Sale Securities AbstractAmortized cost basis, unrealized gains and losses, and approximate fair values of investments in held-to-maturity securitiesHeld To Maturity Securities Text BlockOther Debt Securities [Member]Unrealized LossesHeld To Maturity Securities Unrecognized Holding LossesUnrealized GainsHeld To Maturity Securities Unrecognized Holding GainsFair ValueHeld To Maturity Securities Fair ValueTotal assetsTotal assetsAssetsMajor Types Of Trading Securities And Assets DomainIntangible Assets Disclosure Text BlockINTANGIBLE ASSETSAccounts Receivable, Related Parties, CurrentAssociated companiesInvestment incomeInterest and dividend incomeInvestment incomeInvestment Income Interest And DividendInvestment Income, Interest and Dividend, TotalApproximate fair value and related carrying amounts of notes receivableNotes Receivable Net AbstractOtherOther Liabilities CurrentOtherOther Liabilities NoncurrentProposed Merger With Allegheny Energy, Inc.Proposed Merger With Allegheny Energy, Inc.DIVIDENDS DECLARED PER SHARE OF COMMON STOCKCommon Stock Dividends Per Share DeclaredProceeds from the sale of investments in available-for-sale securities, realized gains and losses on those sales, and interest and dividend incomeAvailable For Sale Securities Gross Realized Gain Loss AbstractFair Value By Balance Sheet Grouping Disclosure Item Amounts AxisFair Value Disclosure Item Amounts DomainCarrying Value [Member]Fair Value [Member]Statement [Table]ASSETSAssets [Abstract]Statement Line ItemsAssets and Liabilities Measured on Recurring BasisFair Value Assets And Liabilities Measured On Recurring Basis AbstractFair Value Assets Measured On Recurring Basis Disclosure Items AxisFair Value Assets Measured On Recurring Basis Disclosure Items DomainInvestmentsFair Value Measured On Recurring Basis InvestmentsDerivativesFair Value Assets Measured On Recurring Basis Derivative Financial Instruments AssetsDerivativesFair Value Liabilities Measured On Recurring Basis Derivative Financial Instruments LiabilitiesReconciliation of changes in the fair value of NUG contractsFair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation AbstractLong-term rate of return on assetsDefined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Expected Long Term Return On AssetsLevel 1 [Member]Level 2 [Member]Level 3 [Member]Fair Value Option Eligible Item Or Group DomainFair Value Option Qualitative Disclosures Related To Election By Eligible Item Or Group AxisFAIR VALUE MEASURESFair Value Disclosures Text BlockFixed Maturities MemberAll Other Corporate Bonds MemberSummary Of Investments Other Than Investments In Related Parties By Type AxisSummary Of Investments By Type DomainDepreciation and amortizationProvision for depreciationDepreciation NonproductionElectric service prepayment programsIncrease Decrease In Deferred RevenueOther operating expensesOther Cost And Expense OperatingOther Cost and Expense, Operating, TotalOtherOther Assets NoncurrentReconciliation of Basic and Diluted Earnings per Share of Common StockEarnings Per Share Reconciliation AbstractEarnings Per Share AbstractGeneral Policies [Abstract]INCOME BEFORE INCOME TAXESIncome Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investmentsncome Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method InvestmentsSchedule Of Available For Sale Securities Major Types Of Debt And Equity Securities AxisAmortized cost basis, unrealized gains and losses, and approximate fair values of investments in held-to-maturity securitiesSchedule Of Held To Maturity Securities Line ItemsParent Company [Member]Deferred income taxes and investment tax credits, netDeferred Income Taxes And Tax CreditsCommon stock, par valueCommon Stock Par Or Stated Value Per ShareCommon stock, $0.10 par value, authorized 375,000,000 shares-304,835,407 shares outstandingCommon Stock Value OutstandingTotal common stockholders' equityStockholders EquityCommon stockholder's equityIncome taxesINCOME TAXESIncome Tax Expense (Benefit)Net interest chargesSegment Reporting Information Interest Income Expense NetCapitalized interestCapitalized interestPublic Utilities Allowance For Funds Used During Construction AdditionsPublic Utility AxisGain on investment securities held in trustsGain Loss On Sale Of InvestmentsPension And Other Postretirement Defined Benefit Plans, Liabilities, NoncurrentPension And Other Postretirement Defined Benefit Plans, Liabilities, NoncurrentRetirement benefitsShort Term Non Bank Loans And Notes PayableAssociated companiesDebt securities issued by the U.S. government [Member]Debt securities issued by states of the U.S. [Member]Fair value of commodity derivativesDerivative Fair Value Of Derivative Net AbstractMajor Types Of Debt Securities [Domain]ReceivablesIncrease Decrease In Accounts And Other ReceivablesLease market valuation liabilityOff Market Lease UnfavorableMerger transactions costsPayments For Merger Related CostsAccumulated Deferred Investment Tax CreditAccumulated deferred investment tax creditsEXPENSES:Costs And Expenses AbstractTotal expensesCosts And ExpensesFGCO [ Member]EARNINGS PER SHAREEarnings Per Share Text BlockNET INCOMENET INCOMENet incomeNet Income (Loss), Including Portion Attributable to Noncontrolling InterestNet losses of the noncontrolling interestsNoncontrolling interest lossLESS:COMPREHENSIVE LOSS ATTRIBUTABLE TO NONCONTROLLING INTERESTNet Income Loss Attributable To Noncontrolling InterestAccrued taxesAccrued Income Taxes CurrentGeneral taxesTaxes Excluding Income And Excise TaxesCOMPREHENSIVE INCOMEComprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling InterestTotal equityStockholders Equity Including Portion Attributable To Noncontrolling InterestHedging Relationship DomainUnrealized LossesAvailable For Sale Securities Gross Unrealized LossActual transmission costs incurredCost Of TransmissionCOMMITMENTS, GUARANTEES AND CONTINGENCIES (Note 8)Commitments And Contingencies 2009Credit Derivatives Contract Type DomainGuarantee Obligations By Payment And Performance Risk Credit Rating AxisOther [Member]Credit Rating DomainAdjustments to reconcile net income to net cash from operating activities-Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities AbstractMaximum ExposureVariable Interest Maximum Exposure To LossCAPITALIZATION:Capitalization Longterm Debt And Equity AbstractNature Of Operations [Text Block]Availableforsale Securities MemberAccounts payableAccounts Payable CurrentOtherAccounts Payable, Related Parties, CurrentAssociated companiesAccounts Payable And Accrued Liabilities Current [Abstract]Accounts payable-Defined Benefit Plan Fair Value Of Plan Assets By Measurement AxisFair Value Plan Asset Measurement DomainRetirement benefitsPension And Other Postretirement Defined Benefit Plans Liabilities NoncurrentEquity Securities Other MemberInvestments In And Advances To Affiliates Categorization [Axis]Investments In And Advances To Affiliates Categorization [Axis]Investments In And Advances To Affiliates Categorization [Domain]Investments In And Advances To Affiliates Categorization [Domain]Derivatives Fair Value By Balance Sheet Location AxisBalance Sheet Location DomainTotal Commodity Derivatives AssetsDerivative Asset Designated As Hedging Instrument Fair ValueTotal Commodity Derivatives LiabilitiesDerivative Liability Designated As Hedging Instrument Fair ValueInterest Rate Contract [Member]Commodity Contract [Member]Derivatives Fair Value By Derivative Instrument Risk [Axis]Cash Flow Hedging MemberIncome Statement And Other Comprehensive Income Location DomainThe aggregate fair value of derivative instruments with credit risk-related contingent featuresDerivative Net Liability Position Aggregate Fair ValueThe aggregate fair value of derivative instruments with credit risk-related contingent features whose collateral has been postedCollateral Already Posted Aggregate Fair ValueAdditional collateral related to commodity derivativesAdditional Collateral Aggregate Fair ValueThe effects of interest rate derivatives on the consolidated statements of income and comprehensive incomeSchedule Of Derivative Instruments Gain Loss In Statement Of Financial Performance Text BlockDerivative Instruments Gain Loss By Hedging Relationship AxisDerivative Instruments Gain Loss By Income Statement Location AxisEffective Gain (Loss) Reclassified to:(1)Derivative Instruments Gain Loss Reclassified From Accumulated OCI Into Income Effective Portion NetReclassified from AOCL into Interest ExpenseDerivative Instruments Loss Reclassified From Accumulated OCI Into Income Effective PortionGain (Loss) Recognized in AOCL (Effective Portion)Derivative Instruments Gain Loss Recognized In Other Comprehensive Income Effective Portion NetFirst Energy recognized losses, ApproximatelyLoss Recognized in AOCLDerivative Instruments, Loss Recognized in Other Comprehensive Income, Effective PortionDerivative Instruments Loss Recognized In Other Comprehensive Income Effective PortionDerivative Instruments Gain Recognized In Other Comprehensive Income Effective PortionGain Recognized in AOCLDerivative Contract Type [Domain]Investment AxisInvestment Domain