Other Income Expense Abstract OTHER INCOME (EXPENSE): Other Income Expense Abstract. Deferred Charges And Other Assets Abstract DEFERRED CHARGES AND OTHER ASSETS: Deferred Charges And Other Assets Abstract. Liabilities And Capitalization Abstract LIABILITIES AND CAPITALIZATION Liabilities And Capitalization Abstract. Total Capitalization Total capitalization Total Capitalization. Net Plant Excluding Construction Work In Progress Total in service, net of accumulated depreciation Net 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 Net Cash collateral received (paid), net Cash Collateral Net. Deferred rents and lease market valuation liability Deferred Rents And Lease Market Valuation Liability. Deferred rents and lease market valuation liability Deferred rents and lease market valuation liability Other Comprehensive Income Loss Abstract. Other Comprehensive Income Loss Abstract OTHER COMPREHENSIVE INCOME (LOSS): 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 Block Reconciliation of Basic and Diluted Earnings per Share of Common Stock Reconciliation of Basic and Diluted Earnings per Share. . Earnings Per Share Details. Earnings Per Share (Details) [Abstract] Recognized tax benefits. Recognized tax benefits Recognized tax benefits Tax benefits favorably affecting effective tax rate. Tax benefits affecting effective tax rate Tax benefits favorably affecting effective tax rate Adjusted accumulated deferred income taxes. Adjusted accumulated deferred income taxes Adjusted accumulated deferred income taxes Repair deduction cost. Repair deduction cost Repair deduction cost Adjusted goodwill. Adjusted goodwill Adjusted goodwill New Accounting Standards and Interpretations (Policies) [Abstract] New Accounting Standards And Interpretations Policies. Income Taxes Details. Income Taxes (Details) [Abstract] Income Taxes Textuals Abstract Income 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 Block Pension benefit costs (including amounts capitalized) Other postretirement benefit costs (including amounts capitalized). Other Postretirement Benefit Costs Including Amounts Capitalized Text Block Other postretirement benefit costs (including amounts capitalized) Periodic Pension Costs Allocated To Parent And Subsidairies Text Block Periodic pension costs (including amounts capitalized) Periodic pension costs allocated to parent and subsidairies. Periodic Postretirement Benefit Costs Allocated To Parent And Subsidairies Text Block Periodic 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 Abstract Pension benefit costs (including amounts capitalized) Pension Benefits. Pension Benefits Abstract Pension Benefits Other postretirement benefit costs (including amounts capitalized). Other Postretirement Benefit Costs Including Amounts Capitalized Abstract Other postretirement benefit costs (including amounts capitalized) Other Postretirement Benefits. Other Postretirement Benefits Abstract Other Postretirement Benefits Periodic Pension Costs Allocated To Parent And Subsidairies Abstract Periodic pension costs (including amounts capitalized) Periodic pension costs allocated to parent and subsidairies. Pension Benefit Cost (Credit). Pension Benefit Cost Credit Abstract Pension Benefit Cost (Credit) Periodic postretirement benefit costs (including amounts capitalized). Periodic Postretirement Benefit Costs Including Amounts Capitalized Abstract Periodic postretirement benefit costs (including amounts capitalized) Other Postretirement Benefit Cost (Credit). Other Postretirement Benefit Cost Credit Abstract Other Postretirement Benefit Cost (Credit) Pension and Other Postretirement Benefits. Pension And Other Postretirement Benefits Textuals Abstract Pension 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 Abstract Commitments, 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 Guarantees Surety bonds and related guarantees Outstanding Collateral Payments Outstanding collateral payments included in other assets Outstanding collateral payments. Change in forward prices first 12 months. Change In Forward Prices First Year FES change in forward prices first 12 months Change In Forward Prices After First Year FES change in forward prices thereafter Change in forward prices there after Surplus Margin Guaranty NGC entered into a Surplus Margin Guaranty Surplus Margin Guaranty. Undivided Interest Percentage sale and leaseback transaction for undivided interest Undivided interest. Penalties per day for violations under emissions regulations. Penalties Per Day For Violations Under Emissions Regulations Penalties per day for violations under emissions regulations Reduction in utility plant NOX emissions from projected 2007 (In Percentage) Reduction In Utility Plant Nox Emissions Reduction in utility plant NOX emissions. Power Plants Complaints Other U.S. power plants complaints Power plants complaints. Averaging period of interim enforcement policy Averaging period of interim enforcement policy (In Days) Averaging period of interim enforcement policy. Notice Letter Required Number of days required prior to the filing of a citizen suit under notice Notice letter, required. Cap And Trade Program To Reduce Mercury Emissions After One Year Cap-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 Years Cap-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 Liabilities Environmental remediation accrued liabilities Parental guarantee associated with funding of decommissioning costs. Parental Guarantee Associated With Funding Of Decommissioning Costs Parental guarantee associated with the funding of decommissioning costs Shortfall net value of decommissioning trust fund. Shortfall Net Value Of Decommissioning Trust Fund Shortfall net value of the decommissioning trust fund Arbitration panel issued an opinion to award. Arbitration Panel Issued Opinion To Award Arbitration panel issued an opinion to award Expected Appeal process Expected Appeal process (In Months) Expected Appeal process. Liability For Potential Award Liability recognized for potential award in 2005 by JCP&L Liability for 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 Sources Forward contracts and future price Forward Contracts And Future Price FES forward contracts and future price After 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 Abstract Regulatory Matters (Textuals) Increase electric distribution rates. Increase Electric Distribution Rates Increase electric distribution rates New Generation Rates For Customers Period for New generation rates for customers beginning in 2009 (In Years) New Generation Rates For Customers. Regulatory Transition Charge Write off Regulatory Transition Charge balance Regulatory Transition Charge. Winning Tranches Auction Winning tranches auction (In Percentage) Winning tranches auction. (In percentage) Utilities Required To Reduce Peak Demand Utilities required to reduce peak demand in 2009 (In Percentage) Utilities required to reduce peak demand in 2009 in percentage. Renewable Energy Resources Equivalent Electric 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 Beginning Ohio Companies filed an MRO to procure electric generation service for the period beginning Electric generation service for the period beginning. New TSC resulted in reduction of monthly billing (In Percentage) New Transmission Service Charge New Transmission Service Charge. Customer prepayments earn interest (In Percentage) Customer prepayments earn interest. Customer Prepayments Earn Interest Maximize energy efficiency to achieve reduction consumption by 2020 (In Percentage) Maximize Energy Efficiency To Achieve Consumption Maximize energy efficiency to achieve consumption. State electricity needs with renewable energy by 2020 (In Percentage) Renewable Energy Renewable energy. Pricing for new transmission facilities that spreads of the cost of new 345 kV and higher transmission facilities (In Percentage) New Transmission Facilities Cost New 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 Period Through Three Months Power Supply Agreement for 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 Period Through One Month Power Supply Agreement for period one month. Excess Congestion Expenses And Marginal Losses Reimburse of congestion expenses and marginal losses in excess of specified limit Excess 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 Cost Transmission cost projections Projected Transmission Cost. Deferred Projected Cost. Deferred Projected Cost Deferred projected cost Deferred accumulated cost, total. Deferred Accumulated Cost Total Deferred accumulated cost, total Infrastructure and energy projects. Infrastructure And Energy Projects Infrastructure and energy projects Current 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 Unit Former ownership of Subsidiary in Work Unit. Capping Of Gas One Emissions Capping of SO2 emissions (In Tons) Capping of SO2 emissions. Capping of Gas Two emissions Capping of NOx emissions (In Tons) Capping of NOx emissions. Uppper threshold limit for carbon di oxide emission Uppper 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 emission Lower 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 Rate Delivery service improvement rider at an overall average rate (Per KWH) Delivery service improvement rider at overall average rate. Delivery service improvement rider at overall average rate Principal Amount plus carrying charges of deferrals. Principal Amount plus carrying charges of deferrals Principal Amount plus carrying charges of deferrals Time required for collection of deferrals amount. Time required for collection of deferrals amount Time required for collection of deferrals amount from September 2009 Recovery of deferral from residential customers. Recovery of deferral from residential customers Recovery of deferral from residential customers Recovery of deferral from non residential customers. Recovery of deferral from non residential customers Recovery of deferral from non-residential customers Weighted Average Wholesale Price For Generation And Transmission Weighted 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 tranche Percentage of load supply per tranche Percentage of load supply per tranche Total annual energy savings. Total annual energy savings Total annual energy savings Review period began after the rule filed with the Joint Committee on Agency Rule Review ( In Days) Review period began after rule filed with Joint Committee on Agency Rule Review. Review period began after rule filed with Joint Committee on Agency Rule Review Defer of projected cost to future Tsc Order And Deferred Projected Cost. Order And Deferred Projected Cost Utilities must provide for the installation of smart meter technology (In Years) Utilities must provide for installation of smart meter technology. Utilities must provide for installation of smart meter technology Minimum reduction in Utilities peak demand (In Percentage) Minimum reduction in Utilities peak demand. Minimum reduction in Utilities peak demand Minimum reduction in Utilities reduce energy consumption (In Percentage) Minimum reduction in Utilities reduce energy consumption. Minimum reduction in Utilities reduce energy consumption Increase in monthly bill of customer (In Percentage) Increase in monthly bill of customer. Increase in monthly bill of customer Additional annual generation revenue. Additional annual generation revenue Additional annual generation revenue Pennsylvania Public Utility Commission Provided For Additional Comment Period PPUC provided for an additional comment period (In Days) Pennslyvania Public Utiltiy Commission provided for additional comment period. Updated estimated decommissioning costs. Updated estimated decommissioning costs Updated estimated decommissioning costs Previously estimated decommissioning costs. Previously estimated decommissioning costs Previously estimated decommissioning costs Reduce Peak Demand For Electricity Reduce peak demand for electricity by 2020 (In MW) Reduce peak demand for electricity in MW. Voltage Transmission Facilities And Zonal Transmission Rate Voltage 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 rate Purchased additional tranches from other bidders. Purchased additional tranches from other bidders Purchased additional tranches from other bidders Weighted average wholesale price for generation and transmission (Per KWH) Weighted average price for generation and transmission. Weighted average price for generation and transmission Increased sale price of power. Increased sale price of power Increased sale prices of power Energy resources required to be supplied by FES (In MW) Energy resources required. Energy resources required Energy purchases by subsidiaries. Energy purchases by subsidiaries Energy 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 casualty value provisions. Net exposure to loss based upon casualty value provisions Abstract Net exposure to loss based upon the casualty value provisions Discounted Lease Payments, net. Variable interest entities discounted lease payments net Discounted Lease Payments, net Variable Interest Entities Net Exposure. Variable Interest Entities Net Exposure Variable Interest Entities Net Exposure Purchased power costs from entities Abstract Purchased power costs from entities: Purchased power costs from entities. Net exposure to loss based upon casualty value provisions. Net exposure to loss based upon casualty value provisions Text Block Net exposure to loss based upon the casualty value provisions Segment Information. Segment Information (Tables) [Abstract] Segment Information. Segment Information (Details) [Abstract] Segment Financial Information. Segment Financial Information Abstract Segment Financial Information Competitive Energy Services [Member] Segment Two. Segment One. Energy Delivery Services [Member] Reconciling Adjustments. Reconciling Adjustments [Member] Variable Interest Entities. Variable Interest Entities Textuals Abstract Variable Interest Entities (Textuals) [Abstract] Variable interest entities distributions to owners. Variable Interest Entities Distributions to owners Distributions to owners Variable interest entities acquisition of additional interest in joint ventures. Variable Interest Entities Acquisition of additional interest in joint ventures Acquisition of additional interest in joint ventures Variable interest entities percentage of mining operations acquired by joint venture Percentage of mining operations acquired by joint venture Variable interest entities percentage of mining operations acquired by joint venture. Variable interest entities Percentage of transportation operations acquired by joint venture Percentage of transportation operations acquired by joint venture Variable 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 venture Economic interest of FEV in joint venture Variable interest entities economic interest of entity two in joint venture Economic interest of an affiliate of the Boich Companies in joint venture Variable 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 additional economic interest Amount agreed to be paid by FEV to affiliates of the Boich Companies for purchase of an additional economic interest Variable interest entities amount agreed to be paid by entity one to entity two for purchase of additional economic interest. Percentage of additional economic interest purchased by entity one Percentage of additional economic interest purchased by FEV in the Signal Peak mining and coal transportation operations Percentage of additional economic interest purchased by entity one. Percentage of remaining stake acquired by joint venture in mining operations. Percentage of remaining stake acquired by joint venture in mining operations Percentage of remaining stake acquired by joint venture in the mining operations Duration of note issued by joint venture Duration of note issued by joint venture. Duration of note issued by joint venture (in years) Variable interest entities Percentage of equity interest by unaffiliated third party included in Ownership of entity three Percentage of equity interest by an unaffiliated third party included in ownership of PNBV Variable interest entities Percentage of equity interest by unaffiliated third party included in Ownership of entity three. Variable interest entities net present value of parent company consolidated sale and leaseback operating lease commitments Net present value of FirstEnergy's consolidated sale and leaseback operating lease commitments Variable 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 Plant Lessor 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 Leaseback Lessor 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 Leaseback Lessor 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 entities Number of long-term power purchase agreements maintained by FirstEnergy with NUG entities Number of long term power purchase agreements maintained by parent company with Non utility generation entities. Transition bonds sold to securitize recovery of subsidiary five bondable stranded costs amount Transition bonds sold to securitize the recovery of JCP&L's bondable stranded costs associated with the divested Oyster Creek Nuclear Generating Station Transition bonds sold to securitize recovery of subsidiary five bondable stranded costs, amount. Entitlement of subsidiary five to aggregate quarterly servicing fees payable from Transition bond charge collections Entitlement of JCP&L to aggregate quarterly servicing fees, payable from TBC collections Entitlement of subsidiary five to aggregate quarterly servicing fees payable from Transition bond charge collections. Segment Information. Segment Information Textuals Abstract Segment Information (Textuals) Issuance Of Notes In Connection With Joint Venture Acqusition Issuance of notes in connection with joint venture acqusition, amount Issuance 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 Four Percentage of equity interest held by OES Ventures, a wholly owned subsidiary of OE Variable 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 Basis Total Fair Value Assets Measured On Recurring Basis. Fair Value Liabilities Measured On Recurring Basis. Fair Value Liabilities Measured On Recurring Basis Total Fair 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 Block Assets and Liabilities Measured on Recurring Basis Fair 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 Block Fair value and related carrying amounts of long-term debt and other long-term obligations Approximate fair value and related carrying amounts of notes receivable. Approximate fair value and related carrying amounts of notes receivable Text Block Approximate fair value and related carrying amounts of notes receivable Proceeds from sale of investments in available-for-sale securities, realized gains and losses on those sales, and interest and dividend income. Proceeds from sale of investments in available for sale securities realized gains and losses on those sales and interest and dividend income Text Block Proceeds from the sale of investments in available-for-sale securities, realized gains and losses on those sales, and interest and dividend income Fair Value of Financial Instruments. Fair Value of Financial Instruments Textuals Abstract Fair Value of Financial Instruments (Textuals) [Abstract] Reconciliation of changes in fair value of Non Utility Generation contracts Text Block Reconciliation of changes in the fair value of NUG contracts Reconciliation of changes in the fair value of Nug contracts. Investments not required to be disclosed. Investments not required to be disclosed Investments not required to be disclosed Investment excludes Receivables, Payables and Accrued income Investments excludes Receivables, Payables and Accrued income Investments 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 Block Fair value of commodity derivatives Noncurrent Liabilities Member. Noncurrent Liabilities [Member] Purchases in (MWH, Gallons, mmBtu) Volume Of Derivatives Purchases. Volume Of Derivatives Purchases Sales in (MWH, Gallons, mmBtu) Volume Of Derivatives Sales. Volume Of Derivatives Sales Net in (MWH, Gallons, mmBtu) Volume Of Derivatives Net. Volume Of Derivatives Net Volume Of Parent Companys Outstanding Derivative Transactions Text Block Volume of First Energy's outstanding derivative transactions Volume 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. Effects of interest rate derivatives on consolidated statements of income and comprehensive income Abstract The effects of interest rate derivatives on the consolidated statements of income and comprehensive income Regulatory Assets Member. Regulatory Assets [Member] Effect of derivative instruments on statements of income and comprehensive income for instruments designated in cash flow hedging relationships and not in hedging relationships. Effect of derivative instruments on statements of income and comprehensive income for instruments designated in cash flow hedging relationships and not in hedging relationships Abstract 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 Volume Of Parent Companys Outstanding Derivative Transaction Abstract Volume of First Energy's outstanding derivative transactions Volume Of Parent Companys Outstanding Derivative Transaction. Derivative Instruments. Derivative Instruments Textuals Abstract Derivative Instruments (Textuals) [Abstract] First Energy terminated forward swaps with a notional value Notional Value of Terminated Forward Swaps Notional value of Terminated forward swaps. Unamortized losses associated with prior interest rate hedges Unamortized losses included in AOCL associated with prior interest rate hedges Unamortized 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 tax Unamortized losses associated with prior interest rate hedges net of tax Unamortized losses included in Aocl associated with commodity derivatives Total unamortized losses included in AOCL associated with commodity derivatives unamortized losses included in AOCL associated with commodity derivatives unamortized 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 tax Total unamortized losses included in AOCL associated with commodity derivatives, Net of tax Change resulted from decrease related to current hedging activity, Net of tax. Change resulted from decrease related to current hedging activity Net of tax Change resulted from decrease related to current hedging activity, Net of tax Decrease due to net hedge losses reclassified to earnings. Decrease due to net hedge losses reclassified to earnings Decrease due to net hedge losses reclassified to earnings long-term debt and other long-term obligations. long term debt and other long term obligations long-term debt and other long-term obligations Fair 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 Abstract Fair value and related carrying amounts of long-term debt and other long-term obligations Other Investments. Other Investments [Member] Cash balance exculded from available for sale securities. Cash balance exculded from available for sale securities Cash balance exculded from available for sale securities Fair 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, Reclassified Derivative 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 earnings Net 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 earnings Derivative Credit Risk Related Contingent Features. Derivative Credit Risk Related Contingent Features [Member] Losses to be amortized to interest expenses during next tweleve months Losses to be amortized to interest expenses during next twelve months Losses to be amortized to interest expenses during next tweleve months. Intangible Assets. Intangible Assets (Details) [Abstract] Intangible Assets. Intangible Assets Textuals Abstract Intangible Assets (Textuals) [Abstract] Proposed Merger. Proposed Merger (Details) [Abstract] Proposed Merger. Proposed Merger Textuals Abstract Proposed Merger With Allegheny Energy, Inc. (Textuals) [Abstract] Merger transactions costs Net of tax Merger transactions costs, net of tax Merger transactions costs, Net of tax. Consumer products Member. Consumer products [Member] Technology Member. Technology [Member] Utilities and energy Member. Utilities and energy [Member] Financial Member. Financial [Member] Right to receive portion of share of common stock of parent company Pursuant to the Merger Agreement, Right to receive portion of a share of common stock of FirstEnergy Right to receive portion of a share of common stock of parent company. Portion Held By Stockholders Of Subsidiary Company In Combined Entity Portion held by stockholders of Allegheny Energy in combined entity Portion held by stockholders of subsidiary company in combined entity Fair Value Measurement With Unobservable Inputs Reconciliation Recurring Basis Asset Liabilities Net Value Ending Balance Beginning Balance Fair 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 Settlements Settlements Fair 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 Losses Unrealized 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 Block Fair value of interest rate swaps Fair value of interest rate swaps. Fair Value Of Interest Rate Swaps Abstract Fair value of interest rate swaps Expected Adverse Change In Quoted Market Prices Derivative Instruments Expected adverse change in quoted market prices of derivative instruments Expected 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 Prices Decrease net income due to adverse change in commodity prices Decrease Net Income Due To Increase In Interest Rates Associated With Variable Rate Debt Decrease net income due to increase in interest rates associated with variable-rate debt Decrease net income due to increase in interest rates associated with variable-rate debt. Power purchase contract liability. Power Purchase Contract Liability Power purchase contract liability Accumulated Provision For Uncollectible Accounts Other Accumulated provision for uncollectible accounts - other Accumulated Provision For Uncollectible Accounts Other. Long Term Contract For Purchase Of Electric Power Cost Incurred Purchased power costs from entities Long Term Contract For Purchase of Electric Power Cost Incurred. Environmental Remediation Liabilities Accrued Total environmental liabilities Environmental Remediation Liabilities Accrued. Utilities Required To Reduce Peak Demand From Two Thousand Ten To Two Thousand Eighteen Utilities required to additional reduction in peak demand through 2018 Utilities Required to Reduce Peak Demand From 2010 To 2018 in percentage Purchase of tranches by bidding Purchase of tranches by bidding. Purchase of tranches by bidding Transition bonds sold to securitize the recovery of deferred costs associated with JCP&L's supply of BGS Initial Bgs Transition Bonds Transition bonds sold to securitize the recovery of deferred costs associated with subsidiary five supply of basic generation service. Guarantees And Surety Bonds Contracts Outstanding collateral payments Guarantees and Surety Bonds Contracts. Supplemental Guarantor Information (Details) [Abstract] Supplemental Guarantor Information Details Abstract MiscellaneousIncomeExpenseAbstract Miscellaneous income (expense), including Miscellaneous income expense Abstact. Interest And Debt Expense Affiliates Interest expense to affiliates Interest expense to affiliates Interest expense to affiliates NGC [Member] Non Guarantor Subsidiaries Two Member Consolidated [Member] FirstEnergy Solutions Corp Consolidated. Investment in associated companies Investment in associated companies. Investment in associated companies Property taxes. Property taxes Property taxes Unamortized sale and leaseback costs. Unamortized sale and leaseback costs Unamortized sale and leaseback costs Property taxes. Property taxes noncurrent liabilities Property taxes Supplemental Guarantor Information Textuals Abstract Supplemental Guarantor Information. Supplemental Guarantor Infromation (Textuals) [Abstract] Sale And Leaseback Transactions Of Undivided Interest Sale and leaseback transactions of undivided interest. Sale and leaseback transactions of undivided interest in Bruce Mansfield OE [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. Non Utility Generation 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 Investments [Member] Nuclear Fuel Disposal Trust Investments Member. Non Utility Generation 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. Non Utility Generation Contract [Member] NUG Contract Member. Asset Retirement Obligations (Details) [Abstract] Asset Retirement Obligations. Asset Retirement Obligations Textuals Abstract Asset Retirement Obligations. Asset Retirement Obligations (Textuals) Supplemental Guarantor Information Abstract Supplemental Guarantor Information Abstract. Supplemental Guarantor Information Disclosure Text Block Supplemental Guarantor Information Disclosure Text Block. Supplemental Guarantor Information (Tables) [Abstract] Supplemental Guarantor Information. First Energy Solutions Corp Condensed Consolidating Statements Of Income Text Block FirstEnergy Solutions Corp Condensed Consolidating Statements of Income. FirstEnergy Solutions Corp Condensed Consolidating Statements Of Income First Energy Solutions Corp Condensed Consolidating Balance Sheets Text Block FirstEnergy Solutions Corp Condensed Consolidating Balance Sheets Text Block. FirstEnergy Solutions Corp Condensed Consolidating Balance Sheets First Energy Solutions Corp Condensed Consolidating Statements Of Cash Flows Text Block FirstEnergy Solutions Corp Condensed Consolidating Statements Of Cash Flows. FirstEnergy Solutions Corp Condensed Consolidating Statements Of Cash Flows Gain Loss On Derivatives The gains and losses from increase (decrease) in fair value of dervatives included in earnings. Commodity derivative transactions, net Leasehold improvement payments to associated companies Leasehold improvement payments to associated companies. Leasehold improvement payments to associated companies Outstanding guarantees related to energy and energy related contracts Outstanding guarantees related to energy and energy related contracts. Acceleration Of Payment [Member] Acceleration Of Payment. Additional collateral payments on parental guarantees Additional collateral payments on parental guarantees. Additional FES collateral payments Additional FES collateral payments. Percent change in confidence level over one year Percent change in confidence level over one year. Surety bonds and lines of credit Surety bonds and lines of credit. Net of tax decrease due to adverse change in commodity prices Net of tax decrease due to adverse change in commodity prices. Hypothetical increase in interest rates Hypothetical increase in the interest rates. Cash proceeds received of May termination Cash proceeds received of May termination. Accrued interest allocation for May termination Accrued interest allocation for May termination. June fixed for floating interest rate swap agreements execution notional amount June fixed-for-floating interest rateswap agreements execution notional amount. Debt underlying June fixed for floating interest rate swap agreements execution Debt underlying the June fixed-for-floating interest rate swap agreements execution. Debt underlying the June fixed-for-floating interest rate swap agreements execution July notional amount of terminated fixed for floating interest rate swap agreements July notional amount of terminated fixed-for-floating interest rate swap agreements. Cash proceeds received of July termination Cash proceeds received of July termination. Net of tax change increase related to current hedging activity Net of tax change increase related to current hedging activity. Collateral has been posted related to fair value of credit related contingent features Collateral has been posted related to fair value of credit related contingent features. Funds provided over next three years Funds provided over the next three years. Funds provided by 2020 Funds provided by 2020. Control drive mechanism requiring modification Control drive mechanism requiring modification. Additional contribution to trust Additional contribution to trust. Reduced parental guarantee Reduced parental guarantee. Protection system relays in able to validate maintenance records Protection system relays in able to validate maintenance records. Total protection system relays Total protection system relays. Generation discount to certain low income customers Generation discount to certain low income customers. Recovery of marginal transmission losses Recovery of marginal transmission losses. Capping of gas one emissions under clean air transport rule Capping of SO2 emissions under Clean Air Transport Rules. Capping of SO2 emissions under CATR Proposed Greenhouse Gas emissions reduction by Twenty Fifty Proposed greenhouse gas emissions reduction by 2050. Weighted average fixed interest rate of interest of interest rate swaps Weighted average fixed interest rate of interest of interest rate swaps. Current weighted average variable rate of interest rate swaps Current weighted average variable rate of interest rate swaps. Accrued interest allocation for July termination Accrued interest allocation for July termination. Nuclear Decommissioning Trust interest and dividend income Nuclear Decommissioning Trust interest and dividend income. Assessment period costs Assessment period costs. Underpayment by Regional Transmission Organization Two Thousand Seven Thru Two Thousand Nine Underpayment by PJM 2007 - 2009. Underpayment by Regional Transmission Organization Two Thousand Five Thru Two Thousand Seven Underpayment by PJM 2005 - 2007. Regulatory asset impairment related to Electric Security Plan Regulatory asset impairment related to Electric Security Plan. Costs avoided by customers Costs avoided by customers. Fund to assist low income customers Fund to assist low income customers. Generation discount for low income customers Generation discount for low income customers. Public Utilities Commission of Ohio review of Market Rate Offer In Days Public Utilities Commission of Ohio review of Market Rate Offer 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 companies Number of customers served by utility operating companies. Number of square miles in service territories in Ohio Pennsylvania and New Jersey Number of square miles in service territories in Ohio Pennsylvania and New Jersey. Megawatts of net demonstrated capacity of competitive segment Megawatts of net demonstrated capacity of competitive segment. Decrease in amount recovered for costs incurred Decrease in the amount recovered for costs incurred. Regional allocation of costs Regional allocation of costs. Revised decommisioning costs Revised decommisioning costs. Effect 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 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 block ffect of derivative instruments on statements of income and comprehensive income for instruments not in hedging relationships text block. Shareholder value at merger agreement date Shareholder value at merger agreement date. Shareholder value at effectiveness date Shareholder value at effectiveness date. Market flow generators Market flow generators. Market flow PJM generators Net underpayments Net underpayments. Net underpayments from PJM to MISO Basis Of Presentation [Text Block] Basis Of Presentation Text Block. Consolidation Of Subsidiaries [Text Block] Consolidation Of Subsidiaries Text Block. Deferral of regulatory asset Deferral of new regulatory assets Deferral of new regulatory assets. Deferral of regulatory assets Cost Of Purchased Power From Affiliates Purchased power from affiliates Purchased power from affiliates. Increase Decrease In Fair Value Used In Annual Goodwill Impairment Test Increase Decrease In Fair Value Used In Annual Goodwill Impairment Test. Increase Decrease In Discount Rate Used In Annual Goodwill Impairment Test Increase Decrease In Discount Rate Used In Annual Goodwill Impairment Test. Derivative Measurement Units Axis Derivative Measurement Unit Domain MWH [Member] Gallons [Member] mmBtu [Member] Other Business Operations [Member] Other Business Operations [Member]. Segment Measurement Unit Axis Segment Measurement Unit Domain Customers [Member] Generating Facilities [Member] Square Miles [Member] Commitments Measurement Units Axis Commitments Measurement Unit Domain Tons [Member] Percent [Member] Subsequent Events Measurement Units Axis Subsequent Events Measurement Unit Domain Regulatory Matters Measurement Units Axis Regulatory Matters Measurement Unit Domain Days [Member] Kv [Member] Goodwill Measurement Units Axis Goodwill Measurement Unit Domain Financing Receivables [Text Block] Financing Receivables Text Block. Unamortized Gains Included Long Term Debt Associated With Prior Fixed For Floating Interest Rate Swaps Unamortized Gains Included In Long Term Debt Associated With Prior Fixed For Floating Interest Rate Swaps. Unamortized Gains Included In Long-Term Debt Associated With Prior Fixed-For-Floating Interest Rate Swaps Fixed For Floating Interest Rate Swaps Amortized To Interest Expense Fixed For Floating Interest Rate Swaps Amortized To Interest Expense. Fixed-For-Floating Interest Rate Swaps Amortized To Interest Expense Unamortized Gains Included Long Term Debt Associated With Prior Fixed For Floating Interest Rate Swaps Net Of Tax Unamortized Gains Included Long Term Debt Associated With Prior Fixed For Floating Interest Rate Swaps Net Of Tax Unamortized Gains Included Long-Term Debt Associated With Prior Fixed-For-Floating Interest Rate Swaps (Net Of Tax) Average Delivery Service Improvement Rider Collection Per Kilowatt Hours Average Delivery Service Improvement Rider Collection Per Kilowatt Hours. Load Cap Load Cap related to new ESP. Load Served From Renewable Energy Resources Load Served From Renewable Energy Resources. Regional Transmission Organization Fees Integration Costs Regional Transmission Organization Fees Integration Costs. Annual Revenue Requirements In Zone Annual Revenue Requirements In ATSI Zone related to Michigan Thumb Project. Environmental Liabilities Former Gas Facilities Environmental Liabilities Former Gas Facilities. Nuclear Plant Decommissioning Trusts Nuclear Plant Decommissioning Trusts. Asset Impairment Charges Text Block Asset Impairment Charges. Asset Impairment Charges [Text Block] Asset Impairment Charges (Details) [Abstract] Asset Impairment Charges Details Abstract. Investment In Consolidated Subsidiary Investment In Consolidated Subsidiary. Investment in subsidiary Adjustment That Increased Income Tax Expense Adjustment That Increased Income Tax Expense. Adjustment that increased income tax expense State Flow Through Tax Benefit State Flow Through Tax Benefit. State flow through tax benefit Bonus First Year Depreciation Percent Bonus First Year Depreciation Percent. Bonus first year depreciation percent Customers (less allowance of $39 million in 2010 and $33 million in 2009) Accounts Receivable Net Current Customers Accounts Receivable, Net, Current, Total Accumulated other comprehensive loss Accumulated Other Comprehensive Income Loss Net Of Tax Less - Accumulated provision for depreciation Accumulated Depreciation Depletion And Amortization Property Plant And Equipment Accumulated Depreciation Depletion And Amortization Property Plant And Equipment, Ending Balance Accumulated Depreciation Depletion And Amortization Property Plant And Equipment, Beginning Balance Other paid-in capital Additional Paid In Capital Common Stock Property additions Property additions Payments To Acquire Productive Assets Payments To Acquire Productive Assets, Total Deferred purchased power and other costs Deferred Purchased Power Costs Gain Loss On Sale Of Derivatives Interest rate swap transactions Gain on asset sales Gain Loss On Sale Of Other Assets Unrealized Gain (Loss) Recognized in: Unrealized Gain Loss On Derivatives Accumulated provision for uncollectible accounts - customer Allowance For Doubtful Accounts Receivable Current Nuclear fuel and lease amortization Other Amortization Of Deferred Charges Amortization of regulatory assets Amortization of regulatory asset Asset Impairment Charges Impairment of long-lived assets Asset Impairment Charges [Abstract] Other Asset Impairment Charges Asset Retirement Obligation Abstract Asset Retirement Obligation Disclosure Text Block ASSET RETIREMENT OBLIGATIONS Asset retirement obligation period increase decrease Asset retirement obligations Asset Retirement Obligations Noncurrent Balance Sheets Unaudited [Abstract] Condensed Consolidating Balance Sheets (Unaudited) Realized gains from the sale of securities held in the nuclear decommissioning trust Realized gains Available For Sale Securities Gross Realized Gains Realized losses Available For Sale Securities Gross Realized Losses Proceeds from sales Available For Sale Securities Gross Realized Gains Losses Sale Proceeds BASIC EARNINGS PER SHARE OF COMMON STOCK Basic earnings per share of common stock Earnings Per Share Basic Bonds Member Cash and cash equivalents at end of period Cash and cash equivalents at beginning of period Cash and cash equivalents Cash And Cash Equivalents At Carrying Value Cash and Cash Equivalents, at Carrying Value, Total Cash Flow Hedge Derivative Assets Cash Flow Hedge Derivative Instrument Assets At Fair Value Cash Flow Hedge Derivative Liabilities Cash Flow Hedge Derivative Instrument Liabilities At Fair Value Net controlled disbursement activity Proceeds From Repayments Of Bank Overdrafts Accrued compensation and retirement benefits Increase Decrease In Employee Related Liabilities Accrued taxes Increase Decrease In Accrued Income Taxes Payable Accrued interest Increase Decrease In Interest Payable Net Materials and supplies Increase Decrease In Inventories Decrease (increase) in operating assets- Increase Decrease In Operating Assets Abstract Increase (decrease) in operating liabilities- Increase Decrease In Operating Liabilities Abstract Prepayments and other current assets Increase Decrease In Prepaid Expense Accounts payable Increase Decrease In Accounts Payable Trade COMMITMENTS, GUARANTEES AND CONTINGENCIES Commitments And Contingencies Disclosure Text Block Power purchase contract asset Commodity Contract Asset Noncurrent Common stock, shares authorized Common Stock Shares Authorized Common stock, shares outstanding Common Stock Shares Outstanding COMPREHENSIVE INCOME (LOSS) AVAILABLE TO FIRSTENERGY CORP. Comprehensive Income Net Of Tax Construction work in progress Construction In Progress Gross Fair value of corporate debt [Member] Corporate debt securities [Member] Fuel Fuel Costs Purchased power Cost Of Purchased Power Purchased power from non-affiliates Total current liabilities Liabilities, Current CURRENT LIABILITIES: Liabilities Current Abstract Currently payable long-term debt Long Term Debt And Capital Lease Obligations Current Long-term debt and other long-term obligations Long-term debt and other long-term obligations Long-term debt and other long-term obligations Long Term Debt And Capital Lease Obligations Debt Securities Member Nuclear plant decommissioning trusts Decommissioning Fund Investments Invested in external trusts for decommissioning and environmental remediation Decommissioning Trust Assets Amount Deferred Tax Assets Deferred Income Accumulated deferred income taxes Accumulated deferred income taxes Deferred Tax Liabilities Noncurrent Defined Benefit Plans Domain Derivative Name Domain Derivative By Nature Axis Derivative [Member] DERIVATIVE INSTRUMENTS Derivative Instruments And Hedging Activities Disclosure Text Block Outstanding guarantees and other assurances aggregated Guarantee Obligations Current Carrying Value Maximum exposure under collateral provisions Guarantee Obligations Maximum Exposure Guarantee Obligations Nature Domain Guarantee Obligations By Nature Axis DILUTED EARNINGS PER SHARE OF COMMON STOCK Diluted earnings per share of common stock Earnings Per Share Diluted Total revenues Revenues Electric Revenue Stock-based compensation Share Based Compensation Capital expenditures for environmental compliance Environmental Remediation Expense Equity investment in the joint venture by FEV Equity Method Investments Equity Securities Member Excise tax collections Excise And Sales Taxes Derivative Assets Fair Value Hedge Assets At Fair Value Fair Value Hedge Assets At Fair Value Derivative Liabilities Fair Value Hedge Liabilities At Fair Value Fair Value Hedge Liabilities At Fair Value Finite Lived Intangible Assets Abstract Amortization expense (approximately) Finite Lived Intangible Assets Amortization Expense Debt securities issued by foreign governments [Member] Electricity Forwards [Member] Natural Gas Futures [Member] Gain in interest expense related to interest rate swaps Gain Loss On Fair Value Hedges Recognized In Earnings Loss on debt redemption Gains Losses On Extinguishment Of Debt Impairment Of Long Lived Assets Held For Use Investment impairment Impairment Of Investments Consolidated Statements of Income (Unaudited) [Abstract] Condensed Consolidated Statements of Income (Unaudited) INCOME TAXES Income Tax Disclosure Text Block Loans from associated companies, net Proceeds From (Payments for) Long-term Loans For Related Parties Restricted funds for debt redemption Restricted funds for debt redemption Increase Decrease In Restricted Cash Assumed exercise of dilutive stock options and awards Incremental Common Shares Attributable To Share Based Payment Arrangements Net intangible assets included in other assets on the FirstEnergy Consolidated Balance Sheet Customer intangibles Goodwill Goodwill Goodwill, Ending Balance Goodwill, Beginning Balance Accrued accumulated interest Unrecognized Tax Benefits Interest On Income Taxes Accrued Interest Rate Swap Member Materials and supplies, at average cost Inventory Net INVESTMENTS: Investments Abstract Letter Of Credit Member Total liabilities and capitalization Liabilities And Stockholders Equity Weighted average fixed interest rate of debt securities Long Term Debt Percentage Bearing Fixed Interest Rate Weighted average variable interest rate of debt securities Long Term Debt Percentage Bearing Variable Interest Rate Total investments Long Term Investments Fair Value Available For Sale Securities Cost Basis Held To Maturity Securities Investments in lease obligation bonds Held To Maturity Securities Noncurrent Noncontrolling interest Minority Interest Net cash provided from (used for) financing activities Net Cash Provided By Used In Financing Activities Net cash used for financing activities CASH FLOWS FROM FINANCING ACTIVITIES: Net Cash Provided By Used In Financing Activities Abstract Net cash used for investing activities Net Cash Provided by (Used in) Investing Activities CASH FLOWS FROM INVESTING ACTIVITIES: Net Cash Provided By Used In Investing Activities Abstract Net cash provided from operating activities Net Cash Provided By Used In Operating Activities NET CASH PROVIDED FROM (USED FOR) OPERATING ACTIVITIES CASH FLOWS FROM OPERATING ACTIVITIES: Net Cash Provided By Used In Operating Activities Abstract EARNINGS AVAILABLE TO FIRSTENERGY CORP. Earnings available to FirstEnergy Corp. Net Income Loss Net change in cash and cash equivalents Cash And Cash Equivalents, Period Increase (Decrease) Cash And Cash Equivalents, Period Increase (Decrease), Total New Accounting Standards and Interpretations [Abstract] New Accounting Standards and Interpretations [Abstract] NEW ACCOUNTING STANDARDS AND INTERPRETATIONS Schedule Of New Accounting Pronouncements And Changes In Accounting Principles Text Block Total other income (expense) Total other expense Nonoperating Income Expense Interest expense Interest expense - other Interest And Debt Expense Interest and Debt Expense, Total Total deferred charges and other assets Assets Noncurrent Total noncurrent liabilities Liabilities Noncurrent NONCURRENT LIABILITIES: Liabilities Noncurrent Abstract Notes receivable Notes Receivable Net Notes Receivable from associated companies Notes Receivable, Related Parties, Current Notional amount of interest rate swaps outstanding Notional Amount Of Interest Rate Derivatives OPERATING INCOME Operating Income Loss REVENUES: Revenues Abstract ORGANIZATION AND BASIS OF PRESENTATION Organization Consolidation And Presentation Of Financial Statements Disclosure Text Block Other Increase Decrease In Other Operating Capital Net Change in unrealized gain on available-for-sale securities Other Comprehensive Income Available For Sale Securities Adjustment Before Tax Period Increase Decrease Other comprehensive income (loss) Other Comprehensive Income Loss Before Tax Period Increase Decrease Increased/Decreased AOCI before tax Pension and other postretirement benefits Other Comprehensive Income Defined Benefit Plans Adjustment Before Tax Period Increase Decrease Unrealized gain on derivative hedges Other Comprehensive Income Derivatives Qualifying As Hedges Before Tax Period Increase Decrease Other comprehensive income (loss), net of tax Other Comprehensive Income Loss Net Of Tax Period Increase Decrease Income tax expense (benefit) related to other comprehensive income Income tax expense (benefit) related to other comprehensive income Other Comprehensive Income Loss Tax Other Other Assets Current Prepayments and other Other Other Payments for (Proceeds from) Other Investing Activities Other Other Long Term Investments Other Proceeds From (Payments For) Other Financing Activities Other Postretirement Benefit Plans Defined Benefit Member Other (less allowance of $7 million in 2010 and 2009) Other Other Receivables Common stock dividend payments Common stock dividend payments Payments Of Dividends Common Stock Pension trust contribution Pension Contributions Pension and OPEB expenses (benefits) Pension And Other Postretirement Benefit Expense PENSION AND OTHER POSTRETIREMENT BENEFITS Pension And Other Postretirement Benefits Disclosure Text Block Pension Plans Defined Benefit Member Recognized net actuarial loss Defined Benefit Plan Actuarial Net Gains Losses Amortization of prior service cost Defined Benefit Plan Amortization Of Prior Service Cost Credit Plan's discount rate Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Discount Rate Expected return on plan assets Defined Benefit Plan Expected Return On Plan Assets Interest cost Defined Benefit Plan Interest Cost Periodic pension costs allocated to parent and subsidairies Net periodic cost (credit) Periodic postretirement benefit costs allocated to parent and subsidairies Defined Benefit Plan Net Periodic Benefit Cost Service cost Defined Benefit Plan Service Cost Defined Benefit Plans Disclosures Defined Benefit Plans Axis Prepaid taxes Prepaid Taxes Proceeds From Contributions From Parent Equity contributions from parent Long-term debt Proceeds From Issuance Of Long Term Debt Proceeds From Issuance Of Long Term Debt, Total Sales of investment securities held in trusts Proceeds From Sale Of Available For Sale Securities Proceeds From Sale Of Available For Sale Securities, Total Proceeds from asset sales Proceeds from asset sales Proceeds from asset sales Short-term borrowings, net Proceeds From Short Term Debt Proceeds From Short Term Debt, Total In service Property Plant And Equipment Gross Property, Plant and Equipment, Gross, Ending Balance Property, Plant and Equipment, Gross, Beginning Balance Property, Plant and Equipment, Gross, Total Total property, plant and equipment Property, Plant And Equipment, Net Property, Plant and Equipment, Net, Ending Balance Property, Plant and Equipment, Net, Beginning Balance Reversal of accrued interest affecting effective tax rate Tax Adjustments Settlements And Unusual Provisions REGULATORY MATTERS Public Utilities Disclosure Text Block Purchased power costs from entities Schedule Of Long Term Contracts For Purchase Of Electric Power Text Block Purchases of investment securities held in trusts Purchases of investment securities held in trusts Payments To Acquire Available For Sale Securities Payments to Acquire Available-for-sale Securities, Total Customer acquisition costs Customer acquisition costs Payments To Acquire Intangible Assets Cash investments Cash investments Payments For Proceeds From Investments Receivables Receivables Net Current [Abstract] Regulatory assets Regulatory Assets Noncurrent Long-term debt Long-term debt Repayments Of Long Term Debt Repayments Of Long Term Debt, Total Short-term borrowings, net Short-term borrowings, net Repayments Of Short Term Debt Repayments Of Short Term Debt, Total Reporting Segment [Domain] Retained earnings Retained Earnings Accumulated Deficit Electric utilities Electric Domestic Regulated Revenue Unregulated businesses Electric Worldwide Unregulated Revenue Deferred gain on sale and leaseback transaction Sale Leaseback Transaction Deferred Gain Net GOODWILL Schedule Of Goodwill Text Block SEGMENT INFORMATION Segment Reporting Disclosure Text Block Segment Financial Information Schedule Of Segment Reporting Information By Segment Text Block Segment Reporting Information Assets Total assets Depreciation and amortization Segment Reporting Information Depreciation Depletion And Amortization Expense Segment Reporting Information Equity In Net Income Of Equity Method Investees Of Segment net income from equity investees Property additions Segment Reporting Information Expenditures For Additions To Long Lived Assets Internal revenues Internal revenues Segment Reporting Information Intersegment Revenue External revenues Segment Reporting Information Revenue From External Customers Segment Reporting Information, by Segment [Axis] Segment Reporting Information Profit Loss Net income (loss) Total revenues Segment Reporting Segment Revenue Short Term Debt Type Domain Short Term Debt Type Axis Short-term borrowings Short Term Borrowings Other Short Term Borrowings [Abstract] Short-term borrowings- Site Contingency Nature Of Contingency Domain Site Contingency By Nature Axis Statements of Cash Flows [Abstract] Consolidated Statements of Comprehensive Income (Unaudited) [Abstract] Common stockholders' equity- Stockholders Equity Abstract Swap Member Total current assets Assets Current CURRENT ASSETS: Assets Current Abstract Transition bonds outstanding Long Term Transition Bond Unrecognized tax benefits expected to resolved within the next twelve month Unrecognized Tax Benefits Increased amount of unrecognized tax benefits Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions Unrecognized benefits (if recognized) affecting effective tax rate Unrecognized Tax Benefits That Would Impact Effective Tax Rate Utilities Operating Expense Impairments Impairment of long-lived assets Impairment of long-lived assets Utility Plant Domain VARIABLE INTEREST ENTITIES Schedule Of Variable Interest Entities Text Block Voting interest of FEV and an affiliate of the Boich Companies in the joint venture Variable Interest Entity Ownership Percentage WEIGHTED AVERAGE NUMBER OF DILUTED SHARES OUTSTANDING Average shares of common stock outstanding - Diluted Weighted Average Number Of Diluted Shares Outstanding WEIGHTED AVERAGE NUMBER OF BASIC SHARES OUTSTANDING Average shares of common stock outstanding - Basic Weighted Average Number Of Shares Outstanding Basic Eliminations [Member] PROPERTY, PLANT AND EQUIPMENT: Property Plant And Equipment Net Abstract Amortized cost basis, unrealized gains and losses and fair values of investments in available-for-sale securities Available For Sale Securities Text Block Major Types Of Debt And Equity Securities Domain Cost Basis Available For Sale Securities Amortized Cost Unrealized Gains Available For Sale Securities Gross Unrealized Gains Amortized cost basis, unrealized gains and losses and fair values of investments in available-for-sale securities Available For Sale Securities Abstract Amortized cost basis, unrealized gains and losses, and approximate fair values of investments in held-to-maturity securities Held To Maturity Securities Text Block Other Debt Securities [Member] Unrealized Losses Held To Maturity Securities Unrecognized Holding Losses Unrealized Gains Held To Maturity Securities Unrecognized Holding Gains Fair Value Held To Maturity Securities Fair Value Total assets Total assets Assets Major Types Of Trading Securities And Assets Domain Intangible Assets Disclosure Text Block INTANGIBLE ASSETS Associated companies Accounts Receivable, Related Parties, Current Investment income Interest and dividend income Investment income Investment Income Interest And Dividend Investment Income, Interest and Dividend, Total Approximate fair value and related carrying amounts of notes receivable Notes Receivable Net Abstract Other Other Liabilities Current Other Other Liabilities Noncurrent Proposed Merger With Allegheny Energy, Inc. Proposed Merger With Allegheny Energy, Inc. DIVIDENDS DECLARED PER SHARE OF COMMON STOCK Common Stock Dividends Per Share Declared Proceeds from the sale of investments in available-for-sale securities, realized gains and losses on those sales, and interest and dividend income Available For Sale Securities Gross Realized Gain Loss Abstract Fair Value By Balance Sheet Grouping Disclosure Item Amounts Axis Fair Value Disclosure Item Amounts Domain Carrying Value [Member] Fair Value [Member] Statement [Table] ASSETS Assets [Abstract] Statement Line Items Assets and Liabilities Measured on Recurring Basis Fair Value Assets And Liabilities Measured On Recurring Basis Abstract Fair Value Assets Measured On Recurring Basis Disclosure Items Axis Fair Value Assets Measured On Recurring Basis Disclosure Items Domain Investments Fair Value Measured On Recurring Basis Investments Derivatives Fair Value Assets Measured On Recurring Basis Derivative Financial Instruments Assets Derivatives Fair Value Liabilities Measured On Recurring Basis Derivative Financial Instruments Liabilities Reconciliation of changes in the fair value of NUG contracts Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation Abstract Long-term rate of return on assets Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Expected Long Term Return On Assets Level 1 [Member] Level 2 [Member] Level 3 [Member] Fair Value Option Eligible Item Or Group Domain Fair Value Option Qualitative Disclosures Related To Election By Eligible Item Or Group Axis FAIR VALUE MEASURES Fair Value Disclosures Text Block Fixed Maturities Member All Other Corporate Bonds Member Summary Of Investments Other Than Investments In Related Parties By Type Axis Summary Of Investments By Type Domain Depreciation and amortization Provision for depreciation Depreciation Nonproduction Electric service prepayment programs Increase Decrease In Deferred Revenue Other operating expenses Other Cost And Expense Operating Other Cost and Expense, Operating, Total Other Other Assets Noncurrent Reconciliation of Basic and Diluted Earnings per Share of Common Stock Earnings Per Share Reconciliation Abstract Earnings Per Share Abstract General Policies [Abstract] INCOME BEFORE INCOME TAXES Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments ncome Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments Schedule Of Available For Sale Securities Major Types Of Debt And Equity Securities Axis Amortized cost basis, unrealized gains and losses, and approximate fair values of investments in held-to-maturity securities Schedule Of Held To Maturity Securities Line Items Parent Company [Member] Deferred income taxes and investment tax credits, net Deferred Income Taxes And Tax Credits Common stock, par value Common Stock Par Or Stated Value Per Share Common stock, $0.10 par value, authorized 375,000,000 shares-304,835,407 shares outstanding Common Stock Value Outstanding Total common stockholders' equity Stockholders Equity Common stockholder's equity Income taxes INCOME TAXES Income Tax Expense (Benefit) Net interest charges Segment Reporting Information Interest Income Expense Net Capitalized interest Capitalized interest Public Utilities Allowance For Funds Used During Construction Additions Public Utility Axis Gain on investment securities held in trusts Gain Loss On Sale Of Investments Pension And Other Postretirement Defined Benefit Plans, Liabilities, Noncurrent Pension And Other Postretirement Defined Benefit Plans, Liabilities, Noncurrent Retirement benefits Short Term Non Bank Loans And Notes Payable Associated companies Segment Reporting Information Goodwill Total goodwill Debt securities issued by the U.S. government [Member] Debt securities issued by states of the U.S. [Member] Fair value of commodity derivatives Derivative Fair Value Of Derivative Net Abstract Major Types Of Debt Securities [Domain] Receivables Increase Decrease In Accounts And Other Receivables Lease market valuation liability Off Market Lease Unfavorable Merger transactions costs Payments For Merger Related Costs Accumulated deferred investment tax credits Accumulated Deferred Investment Tax Credit EXPENSES: Costs And Expenses Abstract Total expenses Costs And Expenses FGCO [ Member] EARNINGS PER SHARE Earnings Per Share Text Block NET INCOME NET INCOME Net income Net Income (Loss), Including Portion Attributable to Noncontrolling Interest Net losses of the noncontrolling interests Loss attributable to noncontrolling interest LESS:COMPREHENSIVE LOSS ATTRIBUTABLE TO NONCONTROLLING INTEREST Net Income Loss Attributable To Noncontrolling Interest Accrued taxes Accrued Income Taxes Current General taxes Taxes Excluding Income And Excise Taxes COMPREHENSIVE INCOME (LOSS) Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest Total equity Stockholders Equity Including Portion Attributable To Noncontrolling Interest Hedging Relationship Domain Unrealized Losses Available For Sale Securities Gross Unrealized Loss Actual transmission costs incurred Cost Of Transmission COMMITMENTS, GUARANTEES AND CONTINGENCIES (Note 8) Commitments And Contingencies 2009 Credit Derivatives Contract Type Domain Guarantee Obligations By Payment And Performance Risk Credit Rating Axis Other [Member] Credit Rating Domain Adjustments to reconcile net income to net cash from operating activities- Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities Abstract Maximum Exposure Variable Interest Maximum Exposure To Loss CAPITALIZATION: Capitalization Longterm Debt And Equity Abstract Nature Of Operations [Text Block] Availableforsale Securities Member Accounts payable Accounts Payable Current Other Associated companies Accounts Payable, Related Parties, Current Accounts Payable And Accrued Liabilities Current [Abstract] Accounts payable- Defined Benefit Plan Fair Value Of Plan Assets By Measurement Axis Fair Value Plan Asset Measurement Domain Retirement benefits Pension And Other Postretirement Defined Benefit Plans Liabilities Noncurrent Equity Securities Other Member Investments 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 Axis Balance Sheet Location Domain Total Commodity Derivatives Assets Derivative Asset Designated As Hedging Instrument Fair Value Total Commodity Derivatives Liabilities Derivative Liability Designated As Hedging Instrument Fair Value Interest Rate Contract [Member] Commodity Contract [Member] Derivatives Fair Value By Derivative Instrument Risk [Axis] Cash Flow Hedging Member Income Statement And Other Comprehensive Income Location Domain The aggregate fair value of derivative instruments with credit risk-related contingent features Derivative Net Liability Position Aggregate Fair Value The aggregate fair value of derivative instruments with credit risk-related contingent features whose collateral has been posted Collateral Already Posted Aggregate Fair Value Additional collateral related to commodity derivatives Additional Collateral Aggregate Fair Value The effects of interest rate derivatives on the consolidated statements of income and comprehensive income Schedule Of Derivative Instruments Gain Loss In Statement Of Financial Performance Text Block Derivative Instruments Gain Loss By Hedging Relationship Axis Derivative Instruments Gain Loss By Income Statement Location Axis Effective Gain (Loss) Reclassified to:(1) Derivative Instruments Gain Loss Reclassified From Accumulated OCI Into Income Effective Portion Net Reclassified from AOCL into Interest Expense Derivative Instruments Loss Reclassified From Accumulated OCI Into Income Effective Portion Gain (Loss) Recognized in AOCL (Effective Portion) Derivative Instruments Gain Loss Recognized In Other Comprehensive Income Effective Portion Net First Energy recognized losses, Approximately Loss Recognized in AOCL Derivative Instruments, Loss Recognized in Other Comprehensive Income, Effective Portion Derivative Instruments Loss Recognized In Other Comprehensive Income Effective Portion Derivative Instruments Gain Recognized In Other Comprehensive Income Effective Portion Gain Recognized in AOCL Derivative Contract Type [Domain] Amendment Flag Current Fiscal Year End Date Document Period End Date Entity [Domain] Entity Well Known Seasoned Issuer Entity Voluntary Filers Entity Current Reporting Status Entity Filer Category Entity Public Float Entity Registrant Name Entity Central Index Key Entity Common Stock Shares Outstanding Document Fiscal Year Focus Document Fiscal Period Focus Legal Entity [Axis] Document Type Investment Axis Investment Domain