2.2.0.7 true Supplemental Guarantor Information (Details) (USD $) 00612 - Disclosure - Supplemental Guarantor Information (Details) true false In Thousands false false 1 USD false false USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 EPS Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 $ false 2 USD false false USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 EPS Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 $ false 3 USD false false USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Tons Standard http://firstenergycorp.com/20100331 tons fe 0 Percent Standard http://www.xbrl.org/2003/instance pure xbrli 0 kV Standard http://firstenergycorp.com/20100331 kV fe 0 Customers Standard http://firstenergycorp.com/20100331 Customers fe 0 Days Standard http://firstenergycorp.com/20100331 Days fe 0 EPS Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 $ false 4 USD false false USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 kV Standard http://firstenergycorp.com/20100331 kV fe 0 EPS Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 $ false 5 USD false false USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Tons Standard http://firstenergycorp.com/20100331 tons fe 0 Percent Standard http://www.xbrl.org/2003/instance pure xbrli 0 MWH Standard http://firstenergycorp.com/20100331 MWH fe 0 Generating_Facilities Standard http://firstenergycorp.com/20100331 Generating_Facilities fe 0 Square_Miles Standard http://firstenergycorp.com/20100331 Square_Miles fe 0 Gallons Standard http://firstenergycorp.com/20100331 Gallons fe 0 mmBTU Standard http://firstenergycorp.com/20100331 mmBTU fe 0 Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 $ false 6 USD false false USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 $ 2 Condensed Consolidated Statements of Income (Unaudited) 2 us-gaap_IncomeStatementAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 3 Total revenues 2 us-gaap_ElectricUtilityRevenue us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 true true false false 3128000000 3128000 [1] false false false 2 true true false false 3271000000 3271000 [1] false false false 3 true true false false 6427000000 6427000 [1] false false false 4 true true false false 6605000000 6605000 [1] false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The aggregate revenue, whether regulated or unregulated, derived from the generation, transmission and distribution of electricity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 1 -Article 5 true 4 EXPENSES: 2 us-gaap_CostsAndExpensesAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 5 Fuel 2 us-gaap_FuelCosts us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 350000000 350000 false false false 2 false true false false 276000000 276000 false false false 3 false true false false 684000000 684000 false false false 4 false true false false 588000000 588000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Fuel costs incurred that are directly related to goods produced and sold and services rendered during the reporting period. No authoritative reference available. false 6 Purchased power 2 us-gaap_CostOfPurchasedPower us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 1052000000 1052000 false false false 2 false true false false 1024000000 1024000 false false false 3 false true false false 2290000000 2290000 false false false 4 false true false false 2167000000 2167000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Cost of electricity purchased and sold during the reporting period. No authoritative reference available. false 7 Other operating expenses 2 us-gaap_OtherCostAndExpenseOperating us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 673000000 673000 false false false 2 false true false false 612000000 612000 false false false 3 false true false false 1374000000 1374000 false false false 4 false true false false 1439000000 1439000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The total amount of other operating cost and expense items that are associated with the entity's normal revenue producing operation. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 3 -Article 5 false 8 Provision for depreciation 2 us-gaap_DepreciationNonproduction us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 190000000 190000 false false false 2 false true false false 185000000 185000 false false false 3 false true false false 383000000 383000 false false false 4 false true false false 362000000 362000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The expense recognized in the current period that allocates the cost of nonproduction tangible assets over their useful lives. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 false 9 Amortization of new regulatory assets 2 us-gaap_AmortizationOfRegulatoryAsset us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 161000000 161000000 false false false 2 false true false false 233000000 233000000 false false false 3 false true false false 373000000 373000000 false false false 4 false true false false 642000000 642000000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The expense charged against earnings during the period to allocate the capitalized costs of regulatory assets over the periods expected to benefit from such costs. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 false 10 Deferral of new regulatory assets 2 fe_DeferralOfRegulatoryAsset fe false credit duration Deferral Of Regulatory Asset. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false true false false -45000000 -45000000 false false false 3 false false false false 0 0 false false false 4 false true false false -136000000 -136000000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Deferral Of Regulatory Asset. No authoritative reference available. false 11 General taxes 2 us-gaap_TaxesExcludingIncomeAndExciseTaxes us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 176000000 176000 false false false 2 false true false false 184000000 184000 false false false 3 false true false false 381000000 381000 false false false 4 false true false false 395000000 395000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary All taxes not related to income of the entity or excise or sales taxes levied on the revenue of the entity that are not reported elsewhere. These taxes could include production, real estate, personal property, and pump tax. No authoritative reference available. true 12 Total expenses 2 us-gaap_CostsAndExpenses us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 2602000000 2602000 false false false 2 false true false false 2469000000 2469000 false false false 3 false true false false 5485000000 5485000 false false false 4 false true false false 5457000000 5457000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Total costs of sales and operating expenses for the period. No authoritative reference available. true 13 OPERATING INCOME 2 us-gaap_OperatingIncomeLoss us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 526000000 526000 false false false 2 false true false false 802000000 802000 false false false 3 false true false false 942000000 942000 false false false 4 false true false false 1148000000 1148000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net result for the period of deducting operating expenses from operating revenues. No authoritative reference available. true 14 OTHER INCOME (EXPENSE): 2 fe_OtherIncomeExpenseAbstract fe false na duration Other Income Expense Abstract. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string Other Income Expense Abstract. false 15 Investment income 2 us-gaap_InvestmentIncomeInterestAndDividend us-gaap true credit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 31000000 31000 false false false 2 false true false false 27000000 27000 false false false 3 false true false false 47000000 47000 false false false 4 false true false false 16000000 16000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Income derived from investments in debt and equity securities and on cash and cash equivalents. Interest income represents earnings which reflect the time value of money or transactions in which the payments are for the use or forbearance of money. Dividend income represents a distribution of earnings to shareholders by investee companies. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 14 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 7 -Subparagraph a, b -Article 5 false 16 Miscellaneous income (expense), including 2 fe_Miscellaneousincomeexpenseabstract fe false na duration Miscellaneous income expense Abstact. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string Miscellaneous income expense Abstact. false 19 Interest expense 2 us-gaap_InterestAndDebtExpense us-gaap true debit duration No definition available. false false false false false false false false false false true negated false 1 false true false false -207000000 -207000 false false false 2 false true false false -206000000 -206000 false false false 3 false true false false -420000000 -420000 false false false 4 false true false false -400000000 -400000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Interest and debt related expenses associated with nonoperating financing activities of the entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 34 -Paragraph 21 false 20 Capitalized interest 2 us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionAdditions us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 40000000 40000 false false false 2 false true false false 33000000 33000 false false false 3 false true false false 81000000 81000 false false false 4 false true false false 61000000 61000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Total increase in earnings in the period representing the cost of equity (rate of return) and borrowed funds (interest rate) used to finance construction of regulated assets, which is expected to be recovered through rate adjustments. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 71 -Paragraph 15 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 90 -Paragraph 8 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 92 -Paragraph 8, 9, 12 true 21 Total other expense 2 us-gaap_NonoperatingIncomeExpense us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false -136000000 -136000 false false false 2 false true false false -146000000 -146000 false false false 3 false true false false -292000000 -292000 false false false 4 false true false false -323000000 -323000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The aggregate amount of income (expense) from ancillary business-related activities (that is to say, excluding major activities considered part of the normal operations of the business). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 7 -Article 5 true 22 INCOME BEFORE INCOME TAXES 2 us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments us-gaap true credit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 390000000 390000 false false false 2 false true false false 656000000 656000 false false false 3 false true false false 650000000 650000 false false false 4 false true false false 825000000 825000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Sum of operating profit and nonoperating income (expense) before income (loss) from equity method investments, income taxes, extraordinary items, cumulative effects of changes in accounting principles, and noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph h -Subparagraph 1(i) -Article 4 false 23 INCOME TAXES 2 us-gaap_IncomeTaxExpenseBenefit us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 134000000 134000 false false false 2 false true false false 248000000 248000 false false false 3 false true false false 245000000 245000 false false false 4 false true false false 302000000 302000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The sum of the current income tax expense (benefit) and the deferred income tax expense (benefit) pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph h -Article 4 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Paragraph 45 -Subparagraph a, b true 24 NET INCOME 2 us-gaap_ProfitLoss us-gaap true credit duration No definition available. false false false false false false false false false false false terselabel false 1 false true false false 256000000 256000 false false false 2 false true false false 408000000 408000 false false false 3 false true false false 405000000 405000 false false false 4 false true false false 523000000 523000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph A1, A4, A5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 5 -Subparagraph b Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 29 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph a Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph c(1) false 25 CURRENT ASSETS: 2 us-gaap_AssetsCurrentAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 26 Cash and cash equivalents 2 us-gaap_CashAndCashEquivalentsAtCarryingValue us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false true false false 900000000 900000 false false false 3 false false false false 0 0 false false false 4 false true false false 900000000 900000 false false false 5 false true false false 281000000 281000 false false false 6 false true false false 874000000 874000 false false false xbrli:monetaryItemType monetary Includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits should not be reported as cash and cash equivalents. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7, 26 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 8, 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7 -Footnote 1 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 false 27 Receivables 2 us-gaap_ReceivablesNetCurrentAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 28 Customers 2 us-gaap_AccountsReceivableNetCurrent us-gaap true debit instant No definition available. false false false false false false false false false false false terselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 1409000000 1409000 false false false 6 false true false false 1244000000 1244000 false false false xbrli:monetaryItemType monetary Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 3 -Subparagraph a(1) -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 4 -Article 5 false 30 Other 2 us-gaap_OtherReceivables us-gaap true debit instant No definition available. false false false false false false false false false false false terselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 146000000 146000 false false false 6 false true false false 153000000 153000 false false false xbrli:monetaryItemType monetary Carrying amounts due as of the balance sheet date from parties or arising from transactions not otherwise specified in the taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 8 -Article 5 false 32 Materials and supplies, at average cost 2 us-gaap_InventoryNet us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 675000000 675000 false false false 6 false true false false 647000000 647000 false false false xbrli:monetaryItemType monetary Carrying amount (lower of cost or market) as of the balance sheet date of inventories less all valuation and other allowances. Excludes noncurrent inventory balances (expected to remain on hand past one year or one operating cycle, if longer). No authoritative reference available. false 33 Prepayments and other 2 us-gaap_OtherAssetsCurrent us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 206000000 206000 false false false 6 false true false false 154000000 154000 false false false xbrli:monetaryItemType monetary Aggregate carrying amount, as of the balance sheet date, of current assets not separately presented elsewhere in the balance sheet. Current assets are expected to be realized or consumed within one year (or the normal operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 8 -Article 5 false 34 Total current assets 2 us-gaap_AssetsCurrent us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 3114000000 3114000 false false false 6 false true false false 3320000000 3320000 false false false xbrli:monetaryItemType monetary Sum of the carrying amounts as of the balance sheet date of all assets that are expected to be realized in cash, sold, or consumed within one year (or the normal operating cycle, if longer). Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 9 -Article 5 true 35 PROPERTY, PLANT AND EQUIPMENT: 2 us-gaap_PropertyPlantAndEquipmentNetAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 36 In service 2 us-gaap_PropertyPlantAndEquipmentGross us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 28274000000 28274000 false false false 6 false true false false 27826000000 27826000 false false false xbrli:monetaryItemType monetary Carrying amount at the balance sheet date for long-lived physical assets used in the normal conduct of business and not intended for resale. This can include land, physical structures, machinery, vehicles, furniture, computer equipment, construction in progress, and similar items. Amount does not include depreciation. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 false 37 Less - Accumulated provision for depreciation 2 us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 11724000000 11724000 false false false 6 false true false false 11397000000 11397000 false false false xbrli:monetaryItemType monetary The cumulative amount of depreciation, depletion and amortization (related to property, plant and equipment, but not including land) that has been recognized in the income statement. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 -Subparagraph c Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 14 -Article 5 true 38 Total in service, net of accumulated depreciation 2 fe_NetPlantExcludingConstructionWorkInProgress fe false debit instant Net Plant Excluding Construction Work In Progress. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 16550000000 16550000 false false false 6 false true false false 16429000000 16429000 false false false xbrli:monetaryItemType monetary Net Plant Excluding Construction Work In Progress. No authoritative reference available. false 39 Construction work in progress 2 us-gaap_ConstructionInProgressGross us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 3000000000 3000000 false false false 6 false true false false 2735000000 2735000 false false false xbrli:monetaryItemType monetary Carrying amount at the balance sheet date of long-lived asset under construction that include construction costs to date on capital projects that have not been completed and assets being constructed that are not ready to be placed into service. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 true 40 Total property, plant and equipment 2 us-gaap_PropertyPlantAndEquipmentNet us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 19550000000 19550000 false false false 6 false true false false 19164000000 19164000 false false false xbrli:monetaryItemType monetary Tangible assets that are held by an entity for use in the production or supply of goods and services, for rental to others, or for administrative purposes and that are expected to provide economic benefit for more than one year; net of accumulated depreciation. Examples include land, buildings, and production equipment. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 13 -Subparagraph a -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 12 -Paragraph 5 -Subparagraph b, c Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 8 -Article 7 true 41 INVESTMENTS: 2 us-gaap_InvestmentsAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 42 Nuclear plant decommissioning trusts 2 us-gaap_DecommissioningFundInvestments us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 1880000000 1880000 false false false 6 false true false false 1859000000 1859000 false false false xbrli:monetaryItemType monetary Decommission fund to pay for the costs of decontaminating and decommissioning of facilities through collection of revenues derived from utility assessments and government appropriations. Decommission fund investment for the process whereby a power station, at the end of its economic life, is taken permanently out of service and its site made available for other purposes. In the case of a nuclear station this comprises three different states of clearance. Immediately after the final closure, radioactive material such as nuclear fuel and operational waste is removed and the buildings surrounding the reactor shield are dismantled and finally the reactor itself is dismantled. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 12 -Article 5 false 44 Other 2 us-gaap_OtherLongTermInvestments us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 589000000 589000 false false false 6 false true false false 621000000 621000 false false false xbrli:monetaryItemType monetary Other noncurrent investments not otherwise specified in the taxonomy, not including investments in marketable securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 12 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 1 -Subparagraph f -Article 7 true 45 Total investments 2 us-gaap_LongTermInvestments us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 2955000000 2955000 false false false 6 false true false false 3023000000 3023000 false false false xbrli:monetaryItemType monetary The total amount of investments that are intended to be held for an extended period of time (longer than one operating cycle). No authoritative reference available. true 46 DEFERRED CHARGES AND OTHER ASSETS: 2 fe_DeferredChargesAndOtherAssetsAbstract fe false na duration Deferred Charges And Other Assets Abstract. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string Deferred Charges And Other Assets Abstract. false 48 Goodwill 2 us-gaap_Goodwill us-gaap true debit instant No definition available. false false false false false false false false false false false false 1 false false false false 0 0 false false false 2 false true false false 5575000000 5575000 false false false 3 false false false false 0 0 false false false 4 false true false false 5575000000 5575000 false false false 5 false true false false 5575000000 5575000 false false false 6 false true false false 5575000000 5575000 false false false xbrli:monetaryItemType monetary Carrying amount as of the balance sheet date, which is the cumulative amount paid, adjusted for any amortization recognized prior to adoption of FAS 142 and for any impairment charges, in excess of the fair value of net assets acquired in one or more business combination transactions. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 142 -Paragraph 43 false 49 Customer intangibles 2 us-gaap_FiniteLivedIntangibleAssetsNet us-gaap true debit instant No definition available. false false false false false false false false false false false false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 118000000 118000 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The aggregate sum of gross carrying value of a major finite-lived intangible asset class, less accumulated amortization and any impairment charges. A major class is composed of intangible assets that can be grouped together because they are similar, either by their nature or by their use in the operations of a company. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 142 -Paragraph 45 -Subparagraph a(1) false 52 Other 2 us-gaap_OtherAssetsNoncurrent us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 825000000 825000 false false false 6 false true false false 666000000 666000 false false false xbrli:monetaryItemType monetary Aggregate carrying amount, as of the balance sheet date, of noncurrent assets not separately disclosed in the balance sheet due to materiality considerations. Noncurrent assets are expected to be realized or consumed after one year (or the normal operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 17 -Article 5 true 53 Total deferred charges and other assets 2 us-gaap_AssetsNoncurrent us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 8847000000 8847000 false false false 6 false true false false 8797000000 8797000 false false false xbrli:monetaryItemType monetary Sum of the carrying amounts as of the balance sheet date of all assets that are expected to be realized in cash, sold or consumed after one year or beyond the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 18 -Article 5 true 54 Total assets 2 us-gaap_Assets us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false false false false 0 0 false false false 2 false true false false 34306000000 34306000 false false false 3 false false false false 0 0 false false false 4 false true false false 34306000000 34306000 false false false 5 false true false false 34466000000 34466000 false false false 6 false true false false 34304000000 34304000 false false false xbrli:monetaryItemType monetary Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Concepts (CON) -Number 6 -Paragraph 25 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 18 -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 12 -Article 7 true 55 CURRENT LIABILITIES: 2 us-gaap_LiabilitiesCurrentAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 56 Currently payable long-term debt 2 us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 1571000000 1571000 false false false 6 false true false false 1834000000 1834000 false false false xbrli:monetaryItemType monetary Obligation related to long-term debt (excluding convertible debt) and capital leases, the portion which is due in one year or less in the future. No authoritative reference available. false 57 Short-term borrowings- 2 us-gaap_ShortTermBorrowingsAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 59 Other 2 us-gaap_ShortTermBorrowings us-gaap true credit instant No definition available. false false false false false false false false false false false terselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 1463000000 1463000 false false false 6 false true false false 1181000000 1181000 false false false xbrli:monetaryItemType monetary Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19 -Subparagraph a -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 13 -Subparagraph 2, 3 -Article 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 16 -Subparagraph a(1) -Article 7 false 60 Accounts payable- 2 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 62 Other 2 us-gaap_AccountsPayableCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false terselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 848000000 848000 false false false 6 false true false false 829000000 829000 false false false xbrli:monetaryItemType monetary Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19 -Subparagraph a -Article 5 false 63 Accrued taxes 2 us-gaap_AccruedIncomeTaxesCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 256000000 256000 false false false 6 false true false false 314000000 314000 false false false xbrli:monetaryItemType monetary Carrying amount as of the balance sheet date of the unpaid sum of the known and estimated amounts payable to satisfy all currently due domestic and foreign income tax obligations. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 15 -Subparagraph b(1) -Article 7 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 15 -Article 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20 -Article 5 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Interpretation (FIN) -Number 48 -Paragraph 15, 21 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Section Appendix E -Paragraph 289 false 64 Other 2 us-gaap_OtherLiabilitiesCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 907000000 907000 false false false 6 false true false false 1130000000 1130000 false false false xbrli:monetaryItemType monetary Aggregate carrying amount, as of the balance sheet date, of current obligations not separately disclosed in the balance sheet due to materiality considerations. Current liabilities are expected to be paid within one year (or the normal operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 43 -Chapter 3 -Section A -Paragraph 8 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 6 -Paragraph 15 true 65 Total current liabilities 2 us-gaap_LiabilitiesCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 5045000000 5045000 false false false 6 false true false false 5288000000 5288000 false false false xbrli:monetaryItemType monetary Total obligations incurred as part of normal operations that are expected to be paid during the following twelve months or within one business cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 21 -Article 5 true 66 CAPITALIZATION: 2 us-gaap_CapitalizationLongtermDebtAndEquityAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 67 Common stockholder's equity 2 us-gaap_StockholdersEquity us-gaap true credit instant No definition available. false false false false false false false false false false false terselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 8839000000 8839000 false false false 6 false true false false 8559000000 8559000 false false false xbrli:monetaryItemType monetary Total of all Stockholders' Equity (deficit) items, net of receivables from officers, directors owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph A3 -Appendix A Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 4 -Section E Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29, 30, 31 -Article 5 false 68 Long-term debt and other long-term obligations 2 us-gaap_LongTermDebtAndCapitalLeaseObligations us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 11861000000 11861000 false false false 6 false true false false 11908000000 11908000 false false false xbrli:monetaryItemType monetary Sum of the carrying values as of the balance sheet date of all long-term debt, which is debt initially having maturities due after one year from the balance sheet date or beyond the operating cycle, if longer, but excluding the portions thereof scheduled to be repaid within one year or the normal operating cycle, if longer plus capital lease obligations due to be paid more than one year after the balance sheet date. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 6 -Section H true 69 Total capitalization 2 fe_TotalCapitalization fe false credit instant Total Capitalization. false false false false false false false false false false false totallabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 20680000000 20680000 false false false 6 false true false false 20465000000 20465000 false false false xbrli:monetaryItemType monetary Total Capitalization. No authoritative reference available. true 70 NONCURRENT LIABILITIES: 2 us-gaap_LiabilitiesNoncurrentAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 71 Deferred gain on sale and leaseback transaction 2 us-gaap_SaleLeasebackTransactionDeferredGainNet us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 976000000 976000 false false false 6 false true false false 993000000 993000 false false false xbrli:monetaryItemType monetary The portion of the gain that will be recorded as income or a reduction in rent expense in future periods less amounts recognized in the current period. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 13 -Paragraph 33 false 72 Accumulated deferred income taxes 2 us-gaap_DeferredTaxLiabilitiesNoncurrent us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 2710000000 2710000 false false false 6 false true false false 2468000000 2468000 false false false xbrli:monetaryItemType monetary Represents the noncurrent portion of deferred tax liabilities, which result from applying the applicable tax rate to net taxable temporary differences pertaining to each jurisdiction to which the entity is obligated to pay income tax. A noncurrent taxable temporary difference is a difference between the tax basis and the carrying amount of a noncurrent asset or liability in the financial statements prepared in accordance with generally accepted accounting principles. In a classified statement of financial position, an enterprise shall separate deferred tax liabilities and assets into a current amount and a noncurrent amount. Deferred tax liabilities and assets shall be classified as current or noncurrent based on the classification of the related asset or liability for financial reporting. A deferred tax liability or asset that is not related to an asset or liability for financial reporting, including deferred tax assets related to carryforwards, shall be classified according to the expected reversal date of the temporary difference. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Paragraph 41, 42 false 74 Asset retirement obligations 2 us-gaap_AssetRetirementObligationsNoncurrent us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 1372000000 1372000 false false false 6 false true false false 1425000000 1425000 false false false xbrli:monetaryItemType monetary Noncurrent portion of the carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 143 -Paragraph 3, 10, 22 false 77 Lease market valuation liability 2 us-gaap_OffMarketLeaseUnfavorable us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 239000000 239000 false false false 6 false true false false 262000000 262000 false false false xbrli:monetaryItemType monetary This element represents a liability associated with the acquisition of an off-market lease when the terms of the lease are unfavorable to the market terms for the lease at the date of acquisition. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141 -Paragraph 37 false 78 Other 2 us-gaap_OtherLiabilitiesNoncurrent us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 1222000000 1222000 false false false 6 false true false false 1226000000 1226000 false false false xbrli:monetaryItemType monetary Aggregate carrying amount, as of the balance sheet date, of noncurrent obligations not separately disclosed in the balance sheet due to materiality considerations. Noncurrent liabilities are expected to be paid after one year (or the normal operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 24 -Article 5 true 79 Total noncurrent liabilities 2 us-gaap_LiabilitiesNoncurrent us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 8741000000 8741000 false false false 6 false true false false 8551000000 8551000 false false false xbrli:monetaryItemType monetary Total obligations incurred as part of normal operations that is expected to be repaid beyond the following twelve months or one business cycle. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22, 23, 24, 25, 26, 27 -Article 5 true 80 Total liabilities and capitalization 2 us-gaap_LiabilitiesAndStockholdersEquity us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 34466000000 34466000 false false false 6 false true false false 34304000000 34304000 false false false xbrli:monetaryItemType monetary Total of all Liabilities and Stockholders' Equity items. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 32 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 25 -Article 7 true 81 Statements of Cash Flows [Abstract] 2 us-gaap_StatementOfCashFlowsAbstract us-gaap true na duration No definition available. false false false false false true false false false false false false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 82 NET CASH PROVIDED FROM (USED FOR) OPERATING ACTIVITIES 2 us-gaap_NetCashProvidedByUsedInOperatingActivities us-gaap true na duration No definition available. false false false false false false false false false false false terselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 858000000 858000 false false false 4 false true false false 1102000000 1102000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net cash from (used in) all of the entity's operating activities, including those of discontinued operations, of the reporting entity. Operating activities generally involve producing and delivering goods and providing services. Operating activity cash flows include transactions, adjustments, and changes in value that are not defined as investing or financing activities. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 26 false 83 New Financing- 2 fe_NewFinancingAbstract fe false na duration New Financing Abstract. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string New Financing Abstract. false 84 Long-term debt 2 us-gaap_ProceedsFromIssuanceOfLongTermDebt us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false 1679000000 1679000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 19 -Subparagraph b false 85 Short-term borrowings, net 2 us-gaap_ProceedsFromShortTermDebt us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 281000000 281000 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash inflow from a borrowing having initial term of repayment within one year or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 19 -Subparagraph b false 86 Redemptions and Repayments- 2 fe_RedemptionsAndRepaymentsAbstract fe false na duration Redemptions And Repayments Abstract. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string Redemptions And Repayments Abstract. false 87 Long-term debt 2 us-gaap_RepaymentsOfLongTermDebt us-gaap true credit duration No definition available. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -407000000 -407000 false false false 4 false true false false -881000000 -881000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 20 -Subparagraph b false 89 Other 2 us-gaap_ProceedsFromPaymentsForOtherFinancingActivities us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -23000000 -23000 false false false 4 false true false false -37000000 -37000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net cash inflow (outflow) from other financing activities. This element is used when there is not a more specific and appropriate element in the taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18, 19, 20 true 90 Net cash used for financing activities 2 us-gaap_NetCashProvidedByUsedInFinancingActivities us-gaap true debit duration No definition available. false false false false false false false false false false false terselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -484000000 -484000 false false false 4 false true false false 426000000 426000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net cash inflow (outflow) from financing activity for the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 26 false 91 CASH FLOWS FROM INVESTING ACTIVITIES: 2 us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 92 Property additions 2 us-gaap_PaymentsToAcquireProductiveAssets us-gaap true credit duration No definition available. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -997000000 -997000 false false false 4 false true false false -1143000000 -1143000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash outflow for purchases of and capital improvements on property, plant and equipment (capital expenditures), software, and other intangible assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 17 -Subparagraph c false 93 Proceeds from asset sales 2 us-gaap_ProceedsFromSaleOfOtherProductiveAssets us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 116000000 116000 false false false 4 false true false false 19000000 19000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash inflow from the sale of other tangible or intangible assets used to produce goods or deliver services not otherwise defined in the taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 16 -Subparagraph c false 94 Sales of investment securities held in trusts 2 us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 1915000000 1915000 false false false 4 false true false false 1001000000 1001000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash inflow associated with the sale of debt and equity securities classified as available-for-sale securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 16 -Subparagraph a Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 18 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 16 -Subparagraph b false 95 Purchases of investment securities held in trusts 2 us-gaap_PaymentsToAcquireAvailableForSaleSecurities us-gaap true credit duration No definition available. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -1934000000 -1934000 false false false 4 false true false false -1041000000 -1041000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash outflow to acquire debt and equity securities not classified as either held-to-maturity securities or trading securities which would be classified as available-for-sale securities and reported at fair value, with unrealized gains and losses excluded from earnings and reported in a separate component of shareholders' equity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 17 -Subparagraph b Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 18 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 17 -Subparagraph a false 97 Customer acquisition costs 2 us-gaap_PaymentsToAcquireIntangibleAssets us-gaap true credit duration No definition available. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -105000000 -105000 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash outflow to acquire asset without physical form usually arising from contractual or other legal rights, excluding goodwill. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 17 -Subparagraph c false 99 Other 2 us-gaap_PaymentsForProceedsFromOtherInvestingActivities us-gaap true credit duration No definition available. false false false false false false false false false false true negatedtotal false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -21000000 -21000 false false false 4 false true false false -49000000 -49000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net cash outflow (inflow) from other investing activities. This element is used when there is not a more specific and appropriate element in the taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 true 100 Net cash used for investing activities 2 us-gaap_NetCashProvidedByUsedInInvestingActivities us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -967000000 -967000 false false false 4 false true false false -1173000000 -1173000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net cash inflow (outflow) from investing activity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 26 true 101 Net change in cash and cash equivalents 2 us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease us-gaap true na duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -593000000 -593000 false false false 4 false true false false 355000000 355000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net change between the beginning and ending balance of cash and cash equivalents. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 26 false 102 Cash and cash equivalents at beginning of period 2 us-gaap_CashAndCashEquivalentsAtCarryingValue us-gaap true debit instant No definition available. false false false false false false false false true false false periodstartlabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false true false false 545000000 545000 false false false 5 false true false false 281000000 281000 false false false 6 false true false false 874000000 874000 false false false xbrli:monetaryItemType monetary Includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits should not be reported as cash and cash equivalents. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7, 26 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 8, 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7 -Footnote 1 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 false 103 Cash and cash equivalents at end of period 2 us-gaap_CashAndCashEquivalentsAtCarryingValue us-gaap true debit instant No definition available. false false false false false false false false false true false periodendlabel false 1 false false false false 0 0 false false false 2 false true false false 900000000 900000 false false false 3 false false false false 0 0 false false false 4 false true false false 900000000 900000 false false false 5 false true false false 281000000 281000 false false false 6 false true false false 874000000 874000 false false false xbrli:monetaryItemType monetary Includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits should not be reported as cash and cash equivalents. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7, 26 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 8, 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7 -Footnote 1 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 false 104 Supplemental Guarantor Infromation (Textuals) [Abstract] 2 fe_SupplementalGuarantorInformationTextualsAbstract fe false na duration Supplemental Guarantor Information. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string Supplemental Guarantor Information. false 105 Sale and leaseback transactions of undivided interest in Bruce Mansfield 2 fe_SaleAndLeasebackTransactionsOfUndividedInterest fe false na instant Sale and leaseback transactions of undivided interest. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false true false false 93.825 93.825 false false false 6 false false false false 0 0 false false false us-types:percentItemType pure Sale and leaseback transactions of undivided interest. No authoritative reference available. false 106 NGC [Member] 0 na true na na No definition available. false true false false false false false false false false false http://firstenergycorp.com/role/disclosuresupplementalguarantorinformationdetails false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false false 7 USD true false false false NGC [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_NonGuarantorSubsidiariesTwoMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 8 USD true false false false NGC [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_NonGuarantorSubsidiariesTwoMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 9 USD true false false false NGC [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_NonGuarantorSubsidiariesTwoMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 10 USD true false false false NGC [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_NonGuarantorSubsidiariesTwoMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 11 USD true false false false NGC [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_NonGuarantorSubsidiariesTwoMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ na No definition available. No authoritative reference available. false 107 Condensed Consolidated Statements of Income (Unaudited) 2 us-gaap_IncomeStatementAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 108 Total revenues 2 us-gaap_ElectricUtilityRevenue us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 338933000 338933 false false false 2 false true false false 389695000 389695 false false false 3 false true false false 765253000 765253 false false false 4 false true false false 785323000 785323 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The aggregate revenue, whether regulated or unregulated, derived from the generation, transmission and distribution of electricity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 1 -Article 5 true 109 EXPENSES: 2 us-gaap_CostsAndExpensesAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 110 Fuel 2 us-gaap_FuelCosts us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 34276000 34276 false false false 2 false true false false 26450000 26450 false false false 3 false true false false 76537000 76537 false false false 4 false true false false 55666000 55666 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Fuel costs incurred that are directly related to goods produced and sold and services rendered during the reporting period. No authoritative reference available. false 112 Other operating expenses 2 us-gaap_OtherCostAndExpenseOperating us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 116350000 116350 false false false 2 false true false false 131159000 131159 false false false 3 false true false false 255770000 255770 false false false 4 false true false false 283615000 283615 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The total amount of other operating cost and expense items that are associated with the entity's normal revenue producing operation. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 3 -Article 5 false 113 Provision for depreciation 2 us-gaap_DepreciationNonproduction us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 36449000 36449 false false false 2 false true false false 35654000 35654 false false false 3 false true false false 73359000 73359 false false false 4 false true false false 67303000 67303 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The expense recognized in the current period that allocates the cost of nonproduction tangible assets over their useful lives. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 false 116 General taxes 2 us-gaap_TaxesExcludingIncomeAndExciseTaxes us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 7327000 7327 false false false 2 false true false false 6184000 6184 false false false 3 false true false false 13975000 13975 false false false 4 false true false false 12228000 12228 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary All taxes not related to income of the entity or excise or sales taxes levied on the revenue of the entity that are not reported elsewhere. These taxes could include production, real estate, personal property, and pump tax. No authoritative reference available. true 117 Total expenses 2 us-gaap_CostsAndExpenses us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 243859000 243859 false false false 2 false true false false 250696000 250696 false false false 3 false true false false 530051000 530051 false false false 4 false true false false 533268000 533268 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Total costs of sales and operating expenses for the period. No authoritative reference available. true 118 OPERATING INCOME 2 us-gaap_OperatingIncomeLoss us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 95074000 95074 false false false 2 false true false false 138999000 138999 false false false 3 false true false false 235202000 235202 false false false 4 false true false false 252055000 252055 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net result for the period of deducting operating expenses from operating revenues. No authoritative reference available. true 119 OTHER INCOME (EXPENSE): 2 fe_OtherIncomeExpenseAbstract fe false na duration Other Income Expense Abstract. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string Other Income Expense Abstract. false 120 Investment income 2 us-gaap_InvestmentIncomeInterestAndDividend us-gaap true credit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 11474000 11474 false false false 2 false true false false 6030000 6030 false false false 3 false true false false 10240000 10240 false false false 4 false true false false -23607000 -23607 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Income derived from investments in debt and equity securities and on cash and cash equivalents. Interest income represents earnings which reflect the time value of money or transactions in which the payments are for the use or forbearance of money. Dividend income represents a distribution of earnings to shareholders by investee companies. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 14 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 7 -Subparagraph a, b -Article 5 false 121 Miscellaneous income (expense), including 2 fe_Miscellaneousincomeexpenseabstract fe false na duration Miscellaneous income expense Abstact. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string Miscellaneous income expense Abstact. false 122 net income from equity investees 2 us-gaap_SegmentReportingInformationEquityInNetIncomeOfEquityMethodInvesteesOfSegment us-gaap true credit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 102000 102 false false false 2 false true false false 0 0 false false false 3 false true false false 1000 1 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Amount of income or loss recognized by the reportable segment for its share of an investee's net income or loss reported under the equity method of accounting. Must be disclosed if the amount (a) is included in the measure of segment profit or loss reviewed by the chief operating decision maker or (b) is otherwise regularly provided to the chief operating decision maker, even if not included in that measure of segment profit or loss Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 131 -Paragraph 27 -Subparagraph g false 123 Interest expense to affiliates 2 fe_Interestanddebtexpenseaffiliates fe false debit duration Interest expense to affiliates false false false false false false false false false false true negated false 1 false true false false -415000 -415 false false false 2 false true false false -1658000 -1658 false false false 3 false true false false -850000 -850 false false false 4 false true false false -2845000 -2845 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Interest expense to affiliates No authoritative reference available. false 124 Interest expense 2 us-gaap_InterestAndDebtExpense us-gaap true debit duration No definition available. false false false false false false false false false false true negated false 1 false true false false -15361000 -15361 false false false 2 false true false false -14677000 -14677 false false false 3 false true false false -31124000 -31124 false false false 4 false true false false -29845000 -29845 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Interest and debt related expenses associated with nonoperating financing activities of the entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 34 -Paragraph 21 false 125 Capitalized interest 2 us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionAdditions us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 4234000 4234 false false false 2 false true false false 2856000 2856 false false false 3 false true false false 7491000 7491 false false false 4 false true false false 5133000 5133 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Total increase in earnings in the period representing the cost of equity (rate of return) and borrowed funds (interest rate) used to finance construction of regulated assets, which is expected to be recovered through rate adjustments. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 71 -Paragraph 15 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 90 -Paragraph 8 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 92 -Paragraph 8, 9, 12 true 126 Total other expense 2 us-gaap_NonoperatingIncomeExpense us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 34000 34 false false false 2 false true false false -7449000 -7449 false false false 3 false true false false -14242000 -14242 false false false 4 false true false false -51164000 -51164 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The aggregate amount of income (expense) from ancillary business-related activities (that is to say, excluding major activities considered part of the normal operations of the business). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 7 -Article 5 true 127 INCOME BEFORE INCOME TAXES 2 us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments us-gaap true credit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 95108000 95108 false false false 2 false true false false 131550000 131550 false false false 3 false true false false 220960000 220960 false false false 4 false true false false 200891000 200891 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Sum of operating profit and nonoperating income (expense) before income (loss) from equity method investments, income taxes, extraordinary items, cumulative effects of changes in accounting principles, and noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph h -Subparagraph 1(i) -Article 4 false 128 INCOME TAXES 2 us-gaap_IncomeTaxExpenseBenefit us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 33550000 33550 false false false 2 false true false false 48163000 48163 false false false 3 false true false false 78563000 78563 false false false 4 false true false false 71092000 71092 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The sum of the current income tax expense (benefit) and the deferred income tax expense (benefit) pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph h -Article 4 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Paragraph 45 -Subparagraph a, b true 129 NET INCOME 2 us-gaap_ProfitLoss us-gaap true credit duration No definition available. false false false false false false false false false false false terselabel false 1 false true false false 61558000 61558 false false false 2 false true false false 83387000 83387 false false false 3 false true false false 142397000 142397 false false false 4 false true false false 129799000 129799 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph A1, A4, A5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 5 -Subparagraph b Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 29 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph a Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph c(1) false 130 CURRENT ASSETS: 2 us-gaap_AssetsCurrentAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 131 Cash and cash equivalents 2 us-gaap_CashAndCashEquivalentsAtCarryingValue us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 9000 9 false false false 2 false true false false 0 0 false false false 3 false true false false 9000 9 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits should not be reported as cash and cash equivalents. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7, 26 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 8, 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7 -Footnote 1 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 false 132 Receivables 2 us-gaap_ReceivablesNetCurrentAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 133 Customers 2 us-gaap_AccountsReceivableNetCurrent us-gaap true debit instant No definition available. false false false false false false false false false false false terselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 3 -Subparagraph a(1) -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 4 -Article 5 false 134 Associated companies 2 us-gaap_AccountsReceivableRelatedPartiesCurrent us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 89725000 89725 false false false 2 false false false false 0 0 false false false 3 false true false false 89725000 89725 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 134841000 134841 false false false xbrli:monetaryItemType monetary Amount of receivables arising from transactions with related parties due within one year or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph k -Subparagraph 1 -Article 4 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 57 -Paragraph 2 -Subparagraph d Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 3 -Subparagraph a -Article 5 false 135 Other 2 us-gaap_OtherReceivables us-gaap true debit instant No definition available. false false false false false false false false false false false terselabel false 1 false true false false 4631000 4631 false false false 2 false false false false 0 0 false false false 3 false true false false 4631000 4631 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 12518000 12518 false false false xbrli:monetaryItemType monetary Carrying amounts due as of the balance sheet date from parties or arising from transactions not otherwise specified in the taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 8 -Article 5 false 136 Notes Receivable from associated companies 2 us-gaap_NotesReceivableRelatedPartiesCurrent us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 89594000 89594 false false false 2 false false false false 0 0 false false false 3 false true false false 89594000 89594 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 147863000 147863 false false false xbrli:monetaryItemType monetary Amounts due from parties associated with the reporting entity as evidenced by a written promise to pay, due within 1 year (or 1 business cycle) Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph k -Subparagraph 1 -Article 4 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 57 -Paragraph 2 -Subparagraph d Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 3 -Subparagraph a -Article 5 false 137 Materials and supplies, at average cost 2 us-gaap_InventoryNet us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 221008000 221008 false false false 2 false false false false 0 0 false false false 3 false true false false 221008000 221008 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 215197000 215197 false false false xbrli:monetaryItemType monetary Carrying amount (lower of cost or market) as of the balance sheet date of inventories less all valuation and other allowances. Excludes noncurrent inventory balances (expected to remain on hand past one year or one operating cycle, if longer). No authoritative reference available. false 138 Prepayments and other 2 us-gaap_OtherAssetsCurrent us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 4069000 4069 false false false 2 false false false false 0 0 false false false 3 false true false false 4069000 4069 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 9401000 9401 false false false xbrli:monetaryItemType monetary Aggregate carrying amount, as of the balance sheet date, of current assets not separately presented elsewhere in the balance sheet. Current assets are expected to be realized or consumed within one year (or the normal operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 8 -Article 5 false 139 Total current assets 2 us-gaap_AssetsCurrent us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 409036000 409036 false false false 2 false false false false 0 0 false false false 3 false true false false 409036000 409036 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 519829000 519829 false false false xbrli:monetaryItemType monetary Sum of the carrying amounts as of the balance sheet date of all assets that are expected to be realized in cash, sold, or consumed within one year (or the normal operating cycle, if longer). Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 9 -Article 5 true 140 PROPERTY, PLANT AND EQUIPMENT: 2 us-gaap_PropertyPlantAndEquipmentNetAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 141 In service 2 us-gaap_PropertyPlantAndEquipmentGross us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 5203976000 5203976 false false false 2 false false false false 0 0 false false false 3 false true false false 5203976000 5203976 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 5174835000 5174835 false false false xbrli:monetaryItemType monetary Carrying amount at the balance sheet date for long-lived physical assets used in the normal conduct of business and not intended for resale. This can include land, physical structures, machinery, vehicles, furniture, computer equipment, construction in progress, and similar items. Amount does not include depreciation. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 false 142 Less - Accumulated provision for depreciation 2 us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 2028479000 2028479 false false false 2 false false false false 0 0 false false false 3 false true false false 2028479000 2028479 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 1910701000 1910701 false false false xbrli:monetaryItemType monetary The cumulative amount of depreciation, depletion and amortization (related to property, plant and equipment, but not including land) that has been recognized in the income statement. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 -Subparagraph c Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 14 -Article 5 true 143 Total in service, net of accumulated depreciation 2 fe_NetPlantExcludingConstructionWorkInProgress fe false debit instant Net Plant Excluding Construction Work In Progress. false false false false false false false false false false false verboselabel false 1 false true false false 3175497000 3175497 false false false 2 false false false false 0 0 false false false 3 false true false false 3175497000 3175497 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 3264134000 3264134 false false false xbrli:monetaryItemType monetary Net Plant Excluding Construction Work In Progress. No authoritative reference available. false 144 Construction work in progress 2 us-gaap_ConstructionInProgressGross us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 466321000 466321 false false false 2 false false false false 0 0 false false false 3 false true false false 466321000 466321 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 368336000 368336 false false false xbrli:monetaryItemType monetary Carrying amount at the balance sheet date of long-lived asset under construction that include construction costs to date on capital projects that have not been completed and assets being constructed that are not ready to be placed into service. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 true 145 Total property, plant and equipment 2 us-gaap_PropertyPlantAndEquipmentNet us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 3641818000 3641818 false false false 2 false false false false 0 0 false false false 3 false true false false 3641818000 3641818 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 3632470000 3632470 false false false xbrli:monetaryItemType monetary Tangible assets that are held by an entity for use in the production or supply of goods and services, for rental to others, or for administrative purposes and that are expected to provide economic benefit for more than one year; net of accumulated depreciation. Examples include land, buildings, and production equipment. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 13 -Subparagraph a -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 12 -Paragraph 5 -Subparagraph b, c Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 8 -Article 7 true 146 INVESTMENTS: 2 us-gaap_InvestmentsAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 147 Nuclear plant decommissioning trusts 2 us-gaap_DecommissioningFundInvestments us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 1107594000 1107594 false false false 2 false false false false 0 0 false false false 3 false true false false 1107594000 1107594 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 1088641000 1088641 false false false xbrli:monetaryItemType monetary Decommission fund to pay for the costs of decontaminating and decommissioning of facilities through collection of revenues derived from utility assessments and government appropriations. Decommission fund investment for the process whereby a power station, at the end of its economic life, is taken permanently out of service and its site made available for other purposes. In the case of a nuclear station this comprises three different states of clearance. Immediately after the final closure, radioactive material such as nuclear fuel and operational waste is removed and the buildings surrounding the reactor shield are dismantled and finally the reactor itself is dismantled. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 12 -Article 5 false 148 Investment in associated companies 2 fe_Investmentinassociatedcompanies fe false debit instant Investment in associated companies. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Investment in associated companies. No authoritative reference available. false 149 Other 2 us-gaap_OtherLongTermInvestments us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 203000 203 false false false 2 false false false false 0 0 false false false 3 false true false false 203000 203 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 202000 202 false false false xbrli:monetaryItemType monetary Other noncurrent investments not otherwise specified in the taxonomy, not including investments in marketable securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 12 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 1 -Subparagraph f -Article 7 true 150 Total investments 2 us-gaap_LongTermInvestments us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 1107797000 1107797 false false false 2 false false false false 0 0 false false false 3 false true false false 1107797000 1107797 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 1088843000 1088843 false false false xbrli:monetaryItemType monetary The total amount of investments that are intended to be held for an extended period of time (longer than one operating cycle). No authoritative reference available. true 151 DEFERRED CHARGES AND OTHER ASSETS: 2 fe_DeferredChargesAndOtherAssetsAbstract fe false na duration Deferred Charges And Other Assets Abstract. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string Deferred Charges And Other Assets Abstract. false 152 Accumulated deferred income taxes 2 us-gaap_DeferredTaxAssetsDeferredIncome us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary The tax effect as of the balance sheet date of the amount of the estimated future tax deductions attributable to income recognized only for tax purposes and which will reverse when recognized under generally accepted accounting principles. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Paragraph 43 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Paragraph 11 -Subparagraph c false 153 Goodwill 2 us-gaap_Goodwill us-gaap true debit instant No definition available. false false false false false false false false false false false false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Carrying amount as of the balance sheet date, which is the cumulative amount paid, adjusted for any amortization recognized prior to adoption of FAS 142 and for any impairment charges, in excess of the fair value of net assets acquired in one or more business combination transactions. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 142 -Paragraph 43 false 154 Customer intangibles 2 us-gaap_FiniteLivedIntangibleAssetsNet us-gaap true debit instant No definition available. false false false false false false false false false false false false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary The aggregate sum of gross carrying value of a major finite-lived intangible asset class, less accumulated amortization and any impairment charges. A major class is composed of intangible assets that can be grouped together because they are similar, either by their nature or by their use in the operations of a company. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 142 -Paragraph 45 -Subparagraph a(1) false 155 Property taxes 2 fe_PropertyTaxes fe false debit instant Property taxes. false false false false false false false false false false false verboselabel false 1 false true false false 22314000 22314 false false false 2 false false false false 0 0 false false false 3 false true false false 22314000 22314 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 22314000 22314 false false false xbrli:monetaryItemType monetary Property taxes. No authoritative reference available. false 156 Unamortized sale and leaseback costs 2 fe_UnamortizedSaleAndLeasebackCosts fe false debit instant Unamortized sale and leaseback costs. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Unamortized sale and leaseback costs. No authoritative reference available. false 157 Other 2 us-gaap_OtherAssetsNoncurrent us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 9655000 9655 false false false 2 false false false false 0 0 false false false 3 false true false false 9655000 9655 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 18755000 18755 false false false xbrli:monetaryItemType monetary Aggregate carrying amount, as of the balance sheet date, of noncurrent assets not separately disclosed in the balance sheet due to materiality considerations. Noncurrent assets are expected to be realized or consumed after one year (or the normal operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 17 -Article 5 true 158 Total deferred charges and other assets 2 us-gaap_AssetsNoncurrent us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 31969000 31969 false false false 2 false false false false 0 0 false false false 3 false true false false 31969000 31969 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 41069000 41069 false false false xbrli:monetaryItemType monetary Sum of the carrying amounts as of the balance sheet date of all assets that are expected to be realized in cash, sold or consumed after one year or beyond the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 18 -Article 5 true 159 Total assets 2 us-gaap_Assets us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 5190620000 5190620 false false false 2 false false false false 0 0 false false false 3 false true false false 5190620000 5190620 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 5282211000 5282211 false false false xbrli:monetaryItemType monetary Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Concepts (CON) -Number 6 -Paragraph 25 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 18 -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 12 -Article 7 true 160 CURRENT LIABILITIES: 2 us-gaap_LiabilitiesCurrentAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 161 Currently payable long-term debt 2 us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 927772000 927772 false false false 2 false false false false 0 0 false false false 3 false true false false 927772000 927772 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 922429000 922429 false false false xbrli:monetaryItemType monetary Obligation related to long-term debt (excluding convertible debt) and capital leases, the portion which is due in one year or less in the future. No authoritative reference available. false 162 Short-term borrowings- 2 us-gaap_ShortTermBorrowingsAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 163 Associated companies 2 us-gaap_ShortTermNonBankLoansAndNotesPayable us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Carrying amount at the balance sheet date of borrowings from a creditor other than a bank, not elsewhere specified in the taxonomy, with a maturity within one year (or within one operating cycle if longer) from the date of borrowing. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19 -Subparagraph a -Article 5 false 164 Other 2 us-gaap_ShortTermBorrowings us-gaap true credit instant No definition available. false false false false false false false false false false false terselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19 -Subparagraph a -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 13 -Subparagraph 2, 3 -Article 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 16 -Subparagraph a(1) -Article 7 false 165 Accounts payable- 2 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 166 Associated companies 2 us-gaap_AccountsPayableRelatedPartiesCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 154508000 154508 false false false 2 false false false false 0 0 false false false 3 false true false false 154508000 154508 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 295045000 295045 false false false xbrli:monetaryItemType monetary Amount for accounts payable to related parties. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19 -Subparagraph a -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 57 -Paragraph 2 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph k -Subparagraph 1 -Article 4 false 167 Other 2 us-gaap_AccountsPayableCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false terselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19 -Subparagraph a -Article 5 false 168 Accrued taxes 2 us-gaap_AccruedIncomeTaxesCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 54576000 54576 false false false 2 false false false false 0 0 false false false 3 false true false false 54576000 54576 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 22777000 22777 false false false xbrli:monetaryItemType monetary Carrying amount as of the balance sheet date of the unpaid sum of the known and estimated amounts payable to satisfy all currently due domestic and foreign income tax obligations. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 15 -Subparagraph b(1) -Article 7 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 15 -Article 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20 -Article 5 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Interpretation (FIN) -Number 48 -Paragraph 15, 21 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Section Appendix E -Paragraph 289 false 169 Other 2 us-gaap_OtherLiabilitiesCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 15377000 15377 false false false 2 false false false false 0 0 false false false 3 false true false false 15377000 15377 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 16734000 16734 false false false xbrli:monetaryItemType monetary Aggregate carrying amount, as of the balance sheet date, of current obligations not separately disclosed in the balance sheet due to materiality considerations. Current liabilities are expected to be paid within one year (or the normal operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 43 -Chapter 3 -Section A -Paragraph 8 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 6 -Paragraph 15 true 170 Total current liabilities 2 us-gaap_LiabilitiesCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 1152233000 1152233 false false false 2 false false false false 0 0 false false false 3 false true false false 1152233000 1152233 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 1256985000 1256985 false false false xbrli:monetaryItemType monetary Total obligations incurred as part of normal operations that are expected to be paid during the following twelve months or within one business cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 21 -Article 5 true 171 CAPITALIZATION: 2 us-gaap_CapitalizationLongtermDebtAndEquityAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 172 Common stockholder's equity 2 us-gaap_StockholdersEquity us-gaap true credit instant No definition available. false false false false false false false false false false false terselabel false 1 false true false false 2268860000 2268860 false false false 2 false false false false 0 0 false false false 3 false true false false 2268860000 2268860 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 2119488000 2119488 false false false xbrli:monetaryItemType monetary Total of all Stockholders' Equity (deficit) items, net of receivables from officers, directors owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph A3 -Appendix A Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 4 -Section E Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29, 30, 31 -Article 5 false 173 Long-term debt and other long-term obligations 2 us-gaap_LongTermDebtAndCapitalLeaseObligations us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 506533000 506533 false false false 2 false false false false 0 0 false false false 3 false true false false 506533000 506533 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 554825000 554825 false false false xbrli:monetaryItemType monetary Sum of the carrying values as of the balance sheet date of all long-term debt, which is debt initially having maturities due after one year from the balance sheet date or beyond the operating cycle, if longer, but excluding the portions thereof scheduled to be repaid within one year or the normal operating cycle, if longer plus capital lease obligations due to be paid more than one year after the balance sheet date. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 6 -Section H true 174 Total capitalization 2 fe_TotalCapitalization fe false credit instant Total Capitalization. false false false false false false false false false false false totallabel false 1 false true false false 2775393000 2775393 false false false 2 false false false false 0 0 false false false 3 false true false false 2775393000 2775393 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 2674313000 2674313 false false false xbrli:monetaryItemType monetary Total Capitalization. No authoritative reference available. true 175 NONCURRENT LIABILITIES: 2 us-gaap_LiabilitiesNoncurrentAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 176 Deferred gain on sale and leaseback transaction 2 us-gaap_SaleLeasebackTransactionDeferredGainNet us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary The portion of the gain that will be recorded as income or a reduction in rent expense in future periods less amounts recognized in the current period. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 13 -Paragraph 33 false 177 Accumulated deferred income taxes 2 us-gaap_DeferredTaxLiabilitiesNoncurrent us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 373725000 373725 false false false 2 false false false false 0 0 false false false 3 false true false false 373725000 373725 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 342840000 342840 false false false xbrli:monetaryItemType monetary Represents the noncurrent portion of deferred tax liabilities, which result from applying the applicable tax rate to net taxable temporary differences pertaining to each jurisdiction to which the entity is obligated to pay income tax. A noncurrent taxable temporary difference is a difference between the tax basis and the carrying amount of a noncurrent asset or liability in the financial statements prepared in accordance with generally accepted accounting principles. In a classified statement of financial position, an enterprise shall separate deferred tax liabilities and assets into a current amount and a noncurrent amount. Deferred tax liabilities and assets shall be classified as current or noncurrent based on the classification of the related asset or liability for financial reporting. A deferred tax liability or asset that is not related to an asset or liability for financial reporting, including deferred tax assets related to carryforwards, shall be classified according to the expected reversal date of the temporary difference. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Paragraph 41, 42 false 178 Accumulated deferred investment tax credits 2 us-gaap_AccumulatedDeferredInvestmentTaxCredit us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 21490000 21490 false false false 2 false false false false 0 0 false false false 3 false true false false 21490000 21490 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 22037000 22037 false false false xbrli:monetaryItemType monetary The noncurrent portion of the reserve for accumulated deferred investment tax credits as of the balance sheet date. This is the remaining investment credit, which will reduce the cost of services collected from ratepayers by a ratable portion over the investment's regulatory life. No authoritative reference available. false 179 Asset retirement obligations 2 us-gaap_AssetRetirementObligationsNoncurrent us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 837213000 837213 false false false 2 false false false false 0 0 false false false 3 false true false false 837213000 837213 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 895734000 895734 false false false xbrli:monetaryItemType monetary Noncurrent portion of the carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 143 -Paragraph 3, 10, 22 false 180 Retirement benefits 2 us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansNoncurrentLiabilities us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary For classified balance sheets this represents the noncurrent liability for underfunded plans recognized in the balance sheet that is associated with the defined benefit pension plans and other postretirement defined benefit plans. For unclassified balance sheets, this represents the entire liability recognized in the balance sheet that is associated with the defined benefit plans. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph c Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 6 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 3 false 181 Property taxes 2 fe_PropertyTaxesNoncurrentLiabilities fe false credit instant Property taxes. false false false false false false false false false false false verboselabel false 1 false true false false 22314000 22314 false false false 2 false false false false 0 0 false false false 3 false true false false 22314000 22314 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 22314000 22314 false false false xbrli:monetaryItemType monetary Property taxes. No authoritative reference available. false 182 Lease market valuation liability 2 us-gaap_OffMarketLeaseUnfavorable us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary This element represents a liability associated with the acquisition of an off-market lease when the terms of the lease are unfavorable to the market terms for the lease at the date of acquisition. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141 -Paragraph 37 false 183 Other 2 us-gaap_OtherLiabilitiesNoncurrent us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 8252000 8252 false false false 2 false false false false 0 0 false false false 3 false true false false 8252000 8252 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 67988000 67988 false false false xbrli:monetaryItemType monetary Aggregate carrying amount, as of the balance sheet date, of noncurrent obligations not separately disclosed in the balance sheet due to materiality considerations. Noncurrent liabilities are expected to be paid after one year (or the normal operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 24 -Article 5 true 184 Total noncurrent liabilities 2 us-gaap_LiabilitiesNoncurrent us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 1262994000 1262994 false false false 2 false false false false 0 0 false false false 3 false true false false 1262994000 1262994 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 1350913000 1350913 false false false xbrli:monetaryItemType monetary Total obligations incurred as part of normal operations that is expected to be repaid beyond the following twelve months or one business cycle. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22, 23, 24, 25, 26, 27 -Article 5 true 185 Total liabilities and capitalization 2 us-gaap_LiabilitiesAndStockholdersEquity us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 5190620000 5190620 false false false 2 false false false false 0 0 false false false 3 false true false false 5190620000 5190620 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 5282211000 5282211 false false false xbrli:monetaryItemType monetary Total of all Liabilities and Stockholders' Equity items. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 32 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 25 -Article 7 true 186 Statements of Cash Flows [Abstract] 2 us-gaap_StatementOfCashFlowsAbstract us-gaap true na duration No definition available. false false false false false true false false false false false false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 187 NET CASH PROVIDED FROM (USED FOR) OPERATING ACTIVITIES 2 us-gaap_NetCashProvidedByUsedInOperatingActivities us-gaap true na duration No definition available. false false false false false false false false false false false terselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 287376000 287376 false false false 4 false true false false 221625000 221625 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net cash from (used in) all of the entity's operating activities, including those of discontinued operations, of the reporting entity. Operating activities generally involve producing and delivering goods and providing services. Operating activity cash flows include transactions, adjustments, and changes in value that are not defined as investing or financing activities. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 26 false 188 New Financing- 2 fe_NewFinancingAbstract fe false na duration New Financing Abstract. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string New Financing Abstract. false 189 Long-term debt 2 us-gaap_ProceedsFromIssuanceOfLongTermDebt us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false true false false 333965000 333965 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 19 -Subparagraph b false 190 Short-term borrowings, net 2 us-gaap_ProceedsFromShortTermDebt us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false 128716000 128716 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash inflow from a borrowing having initial term of repayment within one year or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 19 -Subparagraph b false 191 Redemptions and Repayments- 2 fe_RedemptionsAndRepaymentsAbstract fe false na duration Redemptions And Repayments Abstract. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string Redemptions And Repayments Abstract. false 192 Long-term debt 2 us-gaap_RepaymentsOfLongTermDebt us-gaap true credit duration No definition available. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -42949000 -42949 false false false 4 false true false false -369519000 -369519 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 20 -Subparagraph b false 193 Short-term borrowings, net 2 us-gaap_RepaymentsOfShortTermDebt us-gaap true credit duration No definition available. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash outflow for a borrowing having initial term of repayment within one year or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 20 -Subparagraph b false 194 Other 2 us-gaap_ProceedsFromPaymentsForOtherFinancingActivities us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -101000 -101 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net cash inflow (outflow) from other financing activities. This element is used when there is not a more specific and appropriate element in the taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18, 19, 20 true 195 Net cash used for financing activities 2 us-gaap_NetCashProvidedByUsedInFinancingActivities us-gaap true debit duration No definition available. false false false false false false false false false false false terselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -43050000 -43050 false false false 4 false true false false 93162000 93162 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net cash inflow (outflow) from financing activity for the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 26 false 196 CASH FLOWS FROM INVESTING ACTIVITIES: 2 us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 197 Property additions 2 us-gaap_PaymentsToAcquireProductiveAssets us-gaap true credit duration No definition available. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -229408000 -229408 false false false 4 false true false false -301484000 -301484 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash outflow for purchases of and capital improvements on property, plant and equipment (capital expenditures), software, and other intangible assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 17 -Subparagraph c false 198 Proceeds from asset sales 2 us-gaap_ProceedsFromSaleOfOtherProductiveAssets us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash inflow from the sale of other tangible or intangible assets used to produce goods or deliver services not otherwise defined in the taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 16 -Subparagraph c false 199 Sales of investment securities held in trusts 2 us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 956813000 956813 false false false 4 false true false false 537078000 537078 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash inflow associated with the sale of debt and equity securities classified as available-for-sale securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 16 -Subparagraph a Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 18 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 16 -Subparagraph b false 200 Purchases of investment securities held in trusts 2 us-gaap_PaymentsToAcquireAvailableForSaleSecurities us-gaap true credit duration No definition available. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -978785000 -978785 false false false 4 false true false false -550730000 -550730 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash outflow to acquire debt and equity securities not classified as either held-to-maturity securities or trading securities which would be classified as available-for-sale securities and reported at fair value, with unrealized gains and losses excluded from earnings and reported in a separate component of shareholders' equity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 17 -Subparagraph b Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 18 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 17 -Subparagraph a false 201 Loans from associated companies, net 2 us-gaap_ProceedsFromPaymentsForLongTermLoansForRelatedParties us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 58270000 58270 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash inflow or outflow associated with long-term loans for related parties where one party can exercise control or significant influence over another party, including affiliates, owners or officers and their immediate families, pension trusts, and so forth. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15, 16, 17 false 202 Customer acquisition costs 2 us-gaap_PaymentsToAcquireIntangibleAssets us-gaap true credit duration No definition available. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash outflow to acquire asset without physical form usually arising from contractual or other legal rights, excluding goodwill. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 17 -Subparagraph c false 203 Leasehold improvement payments to associated companies 2 fe_LeaseholdImprovementPaymentsToAssociatedCompanies fe false credit duration Leasehold improvement payments to associated companies. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -51204000 -51204 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Leasehold improvement payments to associated companies. No authoritative reference available. false 204 Other 2 us-gaap_PaymentsForProceedsFromOtherInvestingActivities us-gaap true credit duration No definition available. false false false false false false false false false false true negatedtotal false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -12000 -12 false false false 4 false true false false 349000 349 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net cash outflow (inflow) from other investing activities. This element is used when there is not a more specific and appropriate element in the taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 true 205 Net cash used for investing activities 2 us-gaap_NetCashProvidedByUsedInInvestingActivities us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -244326000 -244326 false false false 4 false true false false -314787000 -314787 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net cash inflow (outflow) from investing activity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 26 true 206 Net change in cash and cash equivalents 2 us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease us-gaap true na duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net change between the beginning and ending balance of cash and cash equivalents. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 26 false 207 Cash and cash equivalents at beginning of period 2 us-gaap_CashAndCashEquivalentsAtCarryingValue us-gaap true debit instant No definition available. false false false false false false false false true false false periodstartlabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 9000 9 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits should not be reported as cash and cash equivalents. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7, 26 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 8, 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7 -Footnote 1 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 false 208 Cash and cash equivalents at end of period 2 us-gaap_CashAndCashEquivalentsAtCarryingValue us-gaap true debit instant No definition available. false false false false false false false false false true false periodendlabel false 1 false true false false 9000 9 false false false 2 false true false false 0 0 false false false 3 false true false false 9000 9 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits should not be reported as cash and cash equivalents. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7, 26 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 8, 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7 -Footnote 1 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 false 211 NGC [Member] | Affiliates Member 0 na true na na No definition available. false true false false false false false false false false false http://firstenergycorp.com/role/disclosuresupplementalguarantorinformationdetails false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false false 12 USD true false false false NGC [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_NonGuarantorSubsidiariesTwoMember dei_LegalEntityAxis explicitMember false false Affiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_AffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 13 USD true false false false NGC [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_NonGuarantorSubsidiariesTwoMember dei_LegalEntityAxis explicitMember false false Affiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_AffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 14 USD true false false false NGC [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_NonGuarantorSubsidiariesTwoMember dei_LegalEntityAxis explicitMember false false Affiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_AffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 15 USD true false false false NGC [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_NonGuarantorSubsidiariesTwoMember dei_LegalEntityAxis explicitMember false false Affiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_AffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ na No definition available. No authoritative reference available. false 214 EXPENSES: 2 us-gaap_CostsAndExpensesAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 216 Purchased power 2 us-gaap_CostOfPurchasedPower us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 49457000 49457 false false false 2 false true false false 51249000 51249 false false false 3 false true false false 110410000 110410 false false false 4 false true false false 114456000 114456 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Cost of electricity purchased and sold during the reporting period. No authoritative reference available. false 316 NGC [Member] | Nonaffiliates Member 0 na true na na No definition available. false true false false false false false false false false false http://firstenergycorp.com/role/disclosuresupplementalguarantorinformationdetails false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false false 16 USD true false false false NGC [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_NonGuarantorSubsidiariesTwoMember dei_LegalEntityAxis explicitMember false false Nonaffiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_NonaffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 17 USD true false false false NGC [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_NonGuarantorSubsidiariesTwoMember dei_LegalEntityAxis explicitMember false false Nonaffiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_NonaffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 18 USD true false false false NGC [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_NonGuarantorSubsidiariesTwoMember dei_LegalEntityAxis explicitMember false false Nonaffiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_NonaffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 19 USD true false false false NGC [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_NonGuarantorSubsidiariesTwoMember dei_LegalEntityAxis explicitMember false false Nonaffiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_NonaffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ na No definition available. No authoritative reference available. false 319 EXPENSES: 2 us-gaap_CostsAndExpensesAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 321 Purchased power 2 us-gaap_CostOfPurchasedPower us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false true false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Cost of electricity purchased and sold during the reporting period. No authoritative reference available. false 421 Eliminations [Member] 0 na true na na No definition available. false true false false false false false false false false false http://firstenergycorp.com/role/disclosuresupplementalguarantorinformationdetails false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false false 20 USD true false false false Eliminations [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_ConsolidationEliminationsMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 21 USD true false false false Eliminations [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_ConsolidationEliminationsMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 22 USD true false false false Eliminations [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_ConsolidationEliminationsMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 23 USD true false false false Eliminations [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_ConsolidationEliminationsMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 24 USD true false false false Eliminations [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_ConsolidationEliminationsMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ na No definition available. No authoritative reference available. false 422 Condensed Consolidated Statements of Income (Unaudited) 2 us-gaap_IncomeStatementAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 423 Total revenues 2 us-gaap_ElectricUtilityRevenue us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false -900580000 -900580 false false false 2 false true false false -819640000 -819640 false false false 3 false true false false -1874196000 -1874196 false false false 4 false true false false -1736983000 -1736983 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The aggregate revenue, whether regulated or unregulated, derived from the generation, transmission and distribution of electricity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 1 -Article 5 true 424 EXPENSES: 2 us-gaap_CostsAndExpensesAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 425 Fuel 2 us-gaap_FuelCosts us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false true false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Fuel costs incurred that are directly related to goods produced and sold and services rendered during the reporting period. No authoritative reference available. false 427 Other operating expenses 2 us-gaap_OtherCostAndExpenseOperating us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 12189000 12189 false false false 2 false true false false 12189000 12189 false false false 3 false true false false 24378000 24378 false false false 4 false true false false 24379000 24379 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The total amount of other operating cost and expense items that are associated with the entity's normal revenue producing operation. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 3 -Article 5 false 428 Provision for depreciation 2 us-gaap_DepreciationNonproduction us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false -1307000 -1307 false false false 2 false true false false -1314000 -1314 false false false 3 false true false false -2616000 -2616 false false false 4 false true false false -2629000 -2629 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The expense recognized in the current period that allocates the cost of nonproduction tangible assets over their useful lives. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 false 431 General taxes 2 us-gaap_TaxesExcludingIncomeAndExciseTaxes us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 0 0 false false false 2 false true false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary All taxes not related to income of the entity or excise or sales taxes levied on the revenue of the entity that are not reported elsewhere. These taxes could include production, real estate, personal property, and pump tax. No authoritative reference available. true 432 Total expenses 2 us-gaap_CostsAndExpenses us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false -889698000 -889698 false false false 2 false true false false -808765000 -808765 false false false 3 false true false false -1852434000 -1852434 false false false 4 false true false false -1715233000 -1715233 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Total costs of sales and operating expenses for the period. No authoritative reference available. true 433 OPERATING INCOME 2 us-gaap_OperatingIncomeLoss us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false -10882000 -10882 false false false 2 false true false false -10875000 -10875 false false false 3 false true false false -21762000 -21762 false false false 4 false true false false -21750000 -21750 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net result for the period of deducting operating expenses from operating revenues. No authoritative reference available. true 434 OTHER INCOME (EXPENSE): 2 fe_OtherIncomeExpenseAbstract fe false na duration Other Income Expense Abstract. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string Other Income Expense Abstract. false 435 Investment income 2 us-gaap_InvestmentIncomeInterestAndDividend us-gaap true credit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false true false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Income derived from investments in debt and equity securities and on cash and cash equivalents. Interest income represents earnings which reflect the time value of money or transactions in which the payments are for the use or forbearance of money. Dividend income represents a distribution of earnings to shareholders by investee companies. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 14 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 7 -Subparagraph a, b -Article 5 false 436 Miscellaneous income (expense), including 2 fe_Miscellaneousincomeexpenseabstract fe false na duration Miscellaneous income expense Abstact. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string Miscellaneous income expense Abstact. false 437 net income from equity investees 2 us-gaap_SegmentReportingInformationEquityInNetIncomeOfEquityMethodInvesteesOfSegment us-gaap true credit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false -147709000 -147709 false false false 2 false true false false -282510000 -282510 false false false 3 false true false false -311038000 -311038 false false false 4 false true false false -399702000 -399702 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Amount of income or loss recognized by the reportable segment for its share of an investee's net income or loss reported under the equity method of accounting. Must be disclosed if the amount (a) is included in the measure of segment profit or loss reviewed by the chief operating decision maker or (b) is otherwise regularly provided to the chief operating decision maker, even if not included in that measure of segment profit or loss Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 131 -Paragraph 27 -Subparagraph g false 438 Interest expense to affiliates 2 fe_Interestanddebtexpenseaffiliates fe false debit duration Interest expense to affiliates false false false false false false false false false false true negated false 1 false true false false 0 0 false false false 2 false true false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Interest expense to affiliates No authoritative reference available. false 439 Interest expense 2 us-gaap_InterestAndDebtExpense us-gaap true debit duration No definition available. false false false false false false false false false false true negated false 1 false true false false 16050000 16050 false false false 2 false true false false 16273000 16273 false false false 3 false true false false 32048000 32048 false false false 4 false true false false 32492000 32492 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Interest and debt related expenses associated with nonoperating financing activities of the entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 34 -Paragraph 21 false 440 Capitalized interest 2 us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionAdditions us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 0 0 false false false 2 false true false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Total increase in earnings in the period representing the cost of equity (rate of return) and borrowed funds (interest rate) used to finance construction of regulated assets, which is expected to be recovered through rate adjustments. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 71 -Paragraph 15 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 90 -Paragraph 8 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 92 -Paragraph 8, 9, 12 true 441 Total other expense 2 us-gaap_NonoperatingIncomeExpense us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false -131659000 -131659 false false false 2 false true false false -266237000 -266237 false false false 3 false true false false -278990000 -278990 false false false 4 false true false false -367210000 -367210 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The aggregate amount of income (expense) from ancillary business-related activities (that is to say, excluding major activities considered part of the normal operations of the business). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 7 -Article 5 true 442 INCOME BEFORE INCOME TAXES 2 us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments us-gaap true credit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false -142541000 -142541 false false false 2 false true false false -277112000 -277112 false false false 3 false true false false -300752000 -300752 false false false 4 false true false false -388960000 -388960 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Sum of operating profit and nonoperating income (expense) before income (loss) from equity method investments, income taxes, extraordinary items, cumulative effects of changes in accounting principles, and noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph h -Subparagraph 1(i) -Article 4 false 443 INCOME TAXES 2 us-gaap_IncomeTaxExpenseBenefit us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 2557000 2557 false false false 2 false true false false 2240000 2240 false false false 3 false true false false 5097000 5097 false false false 4 false true false false 4457000 4457 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The sum of the current income tax expense (benefit) and the deferred income tax expense (benefit) pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph h -Article 4 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Paragraph 45 -Subparagraph a, b true 444 NET INCOME 2 us-gaap_ProfitLoss us-gaap true credit duration No definition available. false false false false false false false false false false false terselabel false 1 false true false false -145098000 -145098 false false false 2 false true false false -279352000 -279352 false false false 3 false true false false -305849000 -305849 false false false 4 false true false false -393417000 -393417 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph A1, A4, A5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 5 -Subparagraph b Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 29 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph a Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph c(1) false 445 CURRENT ASSETS: 2 us-gaap_AssetsCurrentAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 446 Cash and cash equivalents 2 us-gaap_CashAndCashEquivalentsAtCarryingValue us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false true false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits should not be reported as cash and cash equivalents. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7, 26 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 8, 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7 -Footnote 1 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 false 447 Receivables 2 us-gaap_ReceivablesNetCurrentAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 448 Customers 2 us-gaap_AccountsReceivableNetCurrent us-gaap true debit instant No definition available. false false false false false false false false false false false terselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 3 -Subparagraph a(1) -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 4 -Article 5 false 449 Associated companies 2 us-gaap_AccountsReceivableRelatedPartiesCurrent us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false -319936000 -319936 false false false 2 false false false false 0 0 false false false 3 false true false false -319936000 -319936 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false -297308000 -297308 false false false xbrli:monetaryItemType monetary Amount of receivables arising from transactions with related parties due within one year or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph k -Subparagraph 1 -Article 4 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 57 -Paragraph 2 -Subparagraph d Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 3 -Subparagraph a -Article 5 false 450 Other 2 us-gaap_OtherReceivables us-gaap true debit instant No definition available. false false false false false false false false false false false terselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Carrying amounts due as of the balance sheet date from parties or arising from transactions not otherwise specified in the taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 8 -Article 5 false 451 Notes Receivable from associated companies 2 us-gaap_NotesReceivableRelatedPartiesCurrent us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Amounts due from parties associated with the reporting entity as evidenced by a written promise to pay, due within 1 year (or 1 business cycle) Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph k -Subparagraph 1 -Article 4 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 57 -Paragraph 2 -Subparagraph d Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 3 -Subparagraph a -Article 5 false 452 Materials and supplies, at average cost 2 us-gaap_InventoryNet us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Carrying amount (lower of cost or market) as of the balance sheet date of inventories less all valuation and other allowances. Excludes noncurrent inventory balances (expected to remain on hand past one year or one operating cycle, if longer). No authoritative reference available. false 453 Prepayments and other 2 us-gaap_OtherAssetsCurrent us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Aggregate carrying amount, as of the balance sheet date, of current assets not separately presented elsewhere in the balance sheet. Current assets are expected to be realized or consumed within one year (or the normal operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 8 -Article 5 false 454 Total current assets 2 us-gaap_AssetsCurrent us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false -319936000 -319936 false false false 2 false false false false 0 0 false false false 3 false true false false -319936000 -319936 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false -297308000 -297308 false false false xbrli:monetaryItemType monetary Sum of the carrying amounts as of the balance sheet date of all assets that are expected to be realized in cash, sold, or consumed within one year (or the normal operating cycle, if longer). Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 9 -Article 5 true 455 PROPERTY, PLANT AND EQUIPMENT: 2 us-gaap_PropertyPlantAndEquipmentNetAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 456 In service 2 us-gaap_PropertyPlantAndEquipmentGross us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false -385086000 -385086 false false false 2 false false false false 0 0 false false false 3 false true false false -385086000 -385086 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false -386023000 -386023 false false false xbrli:monetaryItemType monetary Carrying amount at the balance sheet date for long-lived physical assets used in the normal conduct of business and not intended for resale. This can include land, physical structures, machinery, vehicles, furniture, computer equipment, construction in progress, and similar items. Amount does not include depreciation. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 false 457 Less - Accumulated provision for depreciation 2 us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false -173191000 -173191 false false false 2 false false false false 0 0 false false false 3 false true false false -173191000 -173191 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false -171512000 -171512 false false false xbrli:monetaryItemType monetary The cumulative amount of depreciation, depletion and amortization (related to property, plant and equipment, but not including land) that has been recognized in the income statement. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 -Subparagraph c Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 14 -Article 5 true 458 Total in service, net of accumulated depreciation 2 fe_NetPlantExcludingConstructionWorkInProgress fe false debit instant Net Plant Excluding Construction Work In Progress. false false false false false false false false false false false verboselabel false 1 false true false false -211895000 -211895 false false false 2 false false false false 0 0 false false false 3 false true false false -211895000 -211895 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false -214511000 -214511 false false false xbrli:monetaryItemType monetary Net Plant Excluding Construction Work In Progress. No authoritative reference available. false 459 Construction work in progress 2 us-gaap_ConstructionInProgressGross us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Carrying amount at the balance sheet date of long-lived asset under construction that include construction costs to date on capital projects that have not been completed and assets being constructed that are not ready to be placed into service. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 true 460 Total property, plant and equipment 2 us-gaap_PropertyPlantAndEquipmentNet us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false -211895000 -211895 false false false 2 false false false false 0 0 false false false 3 false true false false -211895000 -211895 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false -214511000 -214511 false false false xbrli:monetaryItemType monetary Tangible assets that are held by an entity for use in the production or supply of goods and services, for rental to others, or for administrative purposes and that are expected to provide economic benefit for more than one year; net of accumulated depreciation. Examples include land, buildings, and production equipment. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 13 -Subparagraph a -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 12 -Paragraph 5 -Subparagraph b, c Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 8 -Article 7 true 461 INVESTMENTS: 2 us-gaap_InvestmentsAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 462 Nuclear plant decommissioning trusts 2 us-gaap_DecommissioningFundInvestments us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Decommission fund to pay for the costs of decontaminating and decommissioning of facilities through collection of revenues derived from utility assessments and government appropriations. Decommission fund investment for the process whereby a power station, at the end of its economic life, is taken permanently out of service and its site made available for other purposes. In the case of a nuclear station this comprises three different states of clearance. Immediately after the final closure, radioactive material such as nuclear fuel and operational waste is removed and the buildings surrounding the reactor shield are dismantled and finally the reactor itself is dismantled. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 12 -Article 5 false 463 Investment in associated companies 2 fe_Investmentinassociatedcompanies fe false debit instant Investment in associated companies. false false false false false false false false false false false verboselabel false 1 false true false false -4790066000 -4790066 false false false 2 false false false false 0 0 false false false 3 false true false false -4790066000 -4790066 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false -4477602000 -4477602 false false false xbrli:monetaryItemType monetary Investment in associated companies. No authoritative reference available. false 464 Other 2 us-gaap_OtherLongTermInvestments us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Other noncurrent investments not otherwise specified in the taxonomy, not including investments in marketable securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 12 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 1 -Subparagraph f -Article 7 true 465 Total investments 2 us-gaap_LongTermInvestments us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false -4790066000 -4790066 false false false 2 false false false false 0 0 false false false 3 false true false false -4790066000 -4790066 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false -4477602000 -4477602 false false false xbrli:monetaryItemType monetary The total amount of investments that are intended to be held for an extended period of time (longer than one operating cycle). No authoritative reference available. true 466 DEFERRED CHARGES AND OTHER ASSETS: 2 fe_DeferredChargesAndOtherAssetsAbstract fe false na duration Deferred Charges And Other Assets Abstract. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string Deferred Charges And Other Assets Abstract. false 467 Accumulated deferred income taxes 2 us-gaap_DeferredTaxAssetsDeferredIncome us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false -419058000 -419058 false false false 2 false false false false 0 0 false false false 3 false true false false -419058000 -419058 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false -388602000 -388602 false false false xbrli:monetaryItemType monetary The tax effect as of the balance sheet date of the amount of the estimated future tax deductions attributable to income recognized only for tax purposes and which will reverse when recognized under generally accepted accounting principles. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Paragraph 43 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Paragraph 11 -Subparagraph c false 468 Goodwill 2 us-gaap_Goodwill us-gaap true debit instant No definition available. false false false false false false false false false false false false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Carrying amount as of the balance sheet date, which is the cumulative amount paid, adjusted for any amortization recognized prior to adoption of FAS 142 and for any impairment charges, in excess of the fair value of net assets acquired in one or more business combination transactions. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 142 -Paragraph 43 false 469 Customer intangibles 2 us-gaap_FiniteLivedIntangibleAssetsNet us-gaap true debit instant No definition available. false false false false false false false false false false false false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary The aggregate sum of gross carrying value of a major finite-lived intangible asset class, less accumulated amortization and any impairment charges. A major class is composed of intangible assets that can be grouped together because they are similar, either by their nature or by their use in the operations of a company. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 142 -Paragraph 45 -Subparagraph a(1) false 470 Property taxes 2 fe_PropertyTaxes fe false debit instant Property taxes. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Property taxes. No authoritative reference available. false 471 Unamortized sale and leaseback costs 2 fe_UnamortizedSaleAndLeasebackCosts fe false debit instant Unamortized sale and leaseback costs. false false false false false false false false false false false verboselabel false 1 false true false false 63478000 63478 false false false 2 false false false false 0 0 false false false 3 false true false false 63478000 63478 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 56099000 56099 false false false xbrli:monetaryItemType monetary Unamortized sale and leaseback costs. No authoritative reference available. false 472 Other 2 us-gaap_OtherAssetsNoncurrent us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false -60778000 -60778 false false false 2 false false false false 0 0 false false false 3 false true false false -60778000 -60778 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false -51114000 -51114 false false false xbrli:monetaryItemType monetary Aggregate carrying amount, as of the balance sheet date, of noncurrent assets not separately disclosed in the balance sheet due to materiality considerations. Noncurrent assets are expected to be realized or consumed after one year (or the normal operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 17 -Article 5 true 473 Total deferred charges and other assets 2 us-gaap_AssetsNoncurrent us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false -416358000 -416358 false false false 2 false false false false 0 0 false false false 3 false true false false -416358000 -416358 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false -383617000 -383617 false false false xbrli:monetaryItemType monetary Sum of the carrying amounts as of the balance sheet date of all assets that are expected to be realized in cash, sold or consumed after one year or beyond the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 18 -Article 5 true 474 Total assets 2 us-gaap_Assets us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false -5738255000 -5738255 false false false 2 false false false false 0 0 false false false 3 false true false false -5738255000 -5738255 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false -5373038000 -5373038 false false false xbrli:monetaryItemType monetary Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Concepts (CON) -Number 6 -Paragraph 25 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 18 -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 12 -Article 7 true 475 CURRENT LIABILITIES: 2 us-gaap_LiabilitiesCurrentAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 476 Currently payable long-term debt 2 us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false -19101000 -19101 false false false 2 false false false false 0 0 false false false 3 false true false false -19101000 -19101 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false -18640000 -18640 false false false xbrli:monetaryItemType monetary Obligation related to long-term debt (excluding convertible debt) and capital leases, the portion which is due in one year or less in the future. No authoritative reference available. false 477 Short-term borrowings- 2 us-gaap_ShortTermBorrowingsAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 478 Associated companies 2 us-gaap_ShortTermNonBankLoansAndNotesPayable us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Carrying amount at the balance sheet date of borrowings from a creditor other than a bank, not elsewhere specified in the taxonomy, with a maturity within one year (or within one operating cycle if longer) from the date of borrowing. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19 -Subparagraph a -Article 5 false 479 Other 2 us-gaap_ShortTermBorrowings us-gaap true credit instant No definition available. false false false false false false false false false false false terselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19 -Subparagraph a -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 13 -Subparagraph 2, 3 -Article 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 16 -Subparagraph a(1) -Article 7 false 480 Accounts payable- 2 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 481 Associated companies 2 us-gaap_AccountsPayableRelatedPartiesCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false -311849000 -311849 false false false 2 false false false false 0 0 false false false 3 false true false false -311849000 -311849 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false -261201000 -261201 false false false xbrli:monetaryItemType monetary Amount for accounts payable to related parties. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19 -Subparagraph a -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 57 -Paragraph 2 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph k -Subparagraph 1 -Article 4 false 482 Other 2 us-gaap_AccountsPayableCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false terselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19 -Subparagraph a -Article 5 false 483 Accrued taxes 2 us-gaap_AccruedIncomeTaxesCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false -21336000 -21336 false false false 2 false false false false 0 0 false false false 3 false true false false -21336000 -21336 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false -44887000 -44887 false false false xbrli:monetaryItemType monetary Carrying amount as of the balance sheet date of the unpaid sum of the known and estimated amounts payable to satisfy all currently due domestic and foreign income tax obligations. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 15 -Subparagraph b(1) -Article 7 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 15 -Article 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20 -Article 5 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Interpretation (FIN) -Number 48 -Paragraph 15, 21 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Section Appendix E -Paragraph 289 false 484 Other 2 us-gaap_OtherLiabilitiesCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 34722000 34722 false false false 2 false false false false 0 0 false false false 3 false true false false 34722000 34722 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 36994000 36994 false false false xbrli:monetaryItemType monetary Aggregate carrying amount, as of the balance sheet date, of current obligations not separately disclosed in the balance sheet due to materiality considerations. Current liabilities are expected to be paid within one year (or the normal operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 43 -Chapter 3 -Section A -Paragraph 8 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 6 -Paragraph 15 true 485 Total current liabilities 2 us-gaap_LiabilitiesCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false -317564000 -317564 false false false 2 false false false false 0 0 false false false 3 false true false false -317564000 -317564 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false -287734000 -287734 false false false xbrli:monetaryItemType monetary Total obligations incurred as part of normal operations that are expected to be paid during the following twelve months or within one business cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 21 -Article 5 true 486 CAPITALIZATION: 2 us-gaap_CapitalizationLongtermDebtAndEquityAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 487 Common stockholder's equity 2 us-gaap_StockholdersEquity us-gaap true credit instant No definition available. false false false false false false false false false false false terselabel false 1 false true false false -4773279000 -4773279 false false false 2 false false false false 0 0 false false false 3 false true false false -4773279000 -4773279 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false -4466003000 -4466003 false false false xbrli:monetaryItemType monetary Total of all Stockholders' Equity (deficit) items, net of receivables from officers, directors owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph A3 -Appendix A Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 4 -Section E Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29, 30, 31 -Article 5 false 488 Long-term debt and other long-term obligations 2 us-gaap_LongTermDebtAndCapitalLeaseObligations us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false -1259694000 -1259694 false false false 2 false false false false 0 0 false false false 3 false true false false -1259694000 -1259694 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false -1269330000 -1269330 false false false xbrli:monetaryItemType monetary Sum of the carrying values as of the balance sheet date of all long-term debt, which is debt initially having maturities due after one year from the balance sheet date or beyond the operating cycle, if longer, but excluding the portions thereof scheduled to be repaid within one year or the normal operating cycle, if longer plus capital lease obligations due to be paid more than one year after the balance sheet date. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 6 -Section H true 489 Total capitalization 2 fe_TotalCapitalization fe false credit instant Total Capitalization. false false false false false false false false false false false totallabel false 1 false true false false -6032973000 -6032973 false false false 2 false false false false 0 0 false false false 3 false true false false -6032973000 -6032973 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false -5735333000 -5735333 false false false xbrli:monetaryItemType monetary Total Capitalization. No authoritative reference available. true 490 NONCURRENT LIABILITIES: 2 us-gaap_LiabilitiesNoncurrentAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 491 Deferred gain on sale and leaseback transaction 2 us-gaap_SaleLeasebackTransactionDeferredGainNet us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 976012000 976012 false false false 2 false false false false 0 0 false false false 3 false true false false 976012000 976012 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 992869000 992869 false false false xbrli:monetaryItemType monetary The portion of the gain that will be recorded as income or a reduction in rent expense in future periods less amounts recognized in the current period. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 13 -Paragraph 33 false 492 Accumulated deferred income taxes 2 us-gaap_DeferredTaxLiabilitiesNoncurrent us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false -363730000 -363730 false false false 2 false false false false 0 0 false false false 3 false true false false -363730000 -363730 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false -342840000 -342840 false false false xbrli:monetaryItemType monetary Represents the noncurrent portion of deferred tax liabilities, which result from applying the applicable tax rate to net taxable temporary differences pertaining to each jurisdiction to which the entity is obligated to pay income tax. A noncurrent taxable temporary difference is a difference between the tax basis and the carrying amount of a noncurrent asset or liability in the financial statements prepared in accordance with generally accepted accounting principles. In a classified statement of financial position, an enterprise shall separate deferred tax liabilities and assets into a current amount and a noncurrent amount. Deferred tax liabilities and assets shall be classified as current or noncurrent based on the classification of the related asset or liability for financial reporting. A deferred tax liability or asset that is not related to an asset or liability for financial reporting, including deferred tax assets related to carryforwards, shall be classified according to the expected reversal date of the temporary difference. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Paragraph 41, 42 false 493 Accumulated deferred investment tax credits 2 us-gaap_AccumulatedDeferredInvestmentTaxCredit us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary The noncurrent portion of the reserve for accumulated deferred investment tax credits as of the balance sheet date. This is the remaining investment credit, which will reduce the cost of services collected from ratepayers by a ratable portion over the investment's regulatory life. No authoritative reference available. false 494 Asset retirement obligations 2 us-gaap_AssetRetirementObligationsNoncurrent us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Noncurrent portion of the carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 143 -Paragraph 3, 10, 22 false 495 Retirement benefits 2 us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansNoncurrentLiabilities us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary For classified balance sheets this represents the noncurrent liability for underfunded plans recognized in the balance sheet that is associated with the defined benefit pension plans and other postretirement defined benefit plans. For unclassified balance sheets, this represents the entire liability recognized in the balance sheet that is associated with the defined benefit plans. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph c Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 6 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 3 false 496 Property taxes 2 fe_PropertyTaxesNoncurrentLiabilities fe false credit instant Property taxes. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Property taxes. No authoritative reference available. false 497 Lease market valuation liability 2 us-gaap_OffMarketLeaseUnfavorable us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary This element represents a liability associated with the acquisition of an off-market lease when the terms of the lease are unfavorable to the market terms for the lease at the date of acquisition. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141 -Paragraph 37 false 498 Other 2 us-gaap_OtherLiabilitiesNoncurrent us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Aggregate carrying amount, as of the balance sheet date, of noncurrent obligations not separately disclosed in the balance sheet due to materiality considerations. Noncurrent liabilities are expected to be paid after one year (or the normal operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 24 -Article 5 true 499 Total noncurrent liabilities 2 us-gaap_LiabilitiesNoncurrent us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 612282000 612282 false false false 2 false false false false 0 0 false false false 3 false true false false 612282000 612282 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 650029000 650029 false false false xbrli:monetaryItemType monetary Total obligations incurred as part of normal operations that is expected to be repaid beyond the following twelve months or one business cycle. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22, 23, 24, 25, 26, 27 -Article 5 true 500 Total liabilities and capitalization 2 us-gaap_LiabilitiesAndStockholdersEquity us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false -5738255000 -5738255 false false false 2 false false false false 0 0 false false false 3 false true false false -5738255000 -5738255 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false -5373038000 -5373038 false false false xbrli:monetaryItemType monetary Total of all Liabilities and Stockholders' Equity items. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 32 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 25 -Article 7 true 501 Statements of Cash Flows [Abstract] 2 us-gaap_StatementOfCashFlowsAbstract us-gaap true na duration No definition available. false false false false false true false false false false false false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 502 NET CASH PROVIDED FROM (USED FOR) OPERATING ACTIVITIES 2 us-gaap_NetCashProvidedByUsedInOperatingActivities us-gaap true na duration No definition available. false false false false false false false false false false false terselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -9174000 -9174 false false false 4 false true false false -8734000 -8734 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net cash from (used in) all of the entity's operating activities, including those of discontinued operations, of the reporting entity. Operating activities generally involve producing and delivering goods and providing services. Operating activity cash flows include transactions, adjustments, and changes in value that are not defined as investing or financing activities. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 26 false 503 New Financing- 2 fe_NewFinancingAbstract fe false na duration New Financing Abstract. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string New Financing Abstract. false 504 Long-term debt 2 us-gaap_ProceedsFromIssuanceOfLongTermDebt us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 19 -Subparagraph b false 505 Short-term borrowings, net 2 us-gaap_ProceedsFromShortTermDebt us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false -82587000 -82587 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash inflow from a borrowing having initial term of repayment within one year or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 19 -Subparagraph b false 506 Redemptions and Repayments- 2 fe_RedemptionsAndRepaymentsAbstract fe false na duration Redemptions And Repayments Abstract. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string Redemptions And Repayments Abstract. false 507 Long-term debt 2 us-gaap_RepaymentsOfLongTermDebt us-gaap true credit duration No definition available. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 9174000 9174 false false false 4 false true false false 8734000 8734 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 20 -Subparagraph b false 508 Short-term borrowings, net 2 us-gaap_RepaymentsOfShortTermDebt us-gaap true credit duration No definition available. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false 82587000 82587 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash outflow for a borrowing having initial term of repayment within one year or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 20 -Subparagraph b false 509 Other 2 us-gaap_ProceedsFromPaymentsForOtherFinancingActivities us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net cash inflow (outflow) from other financing activities. This element is used when there is not a more specific and appropriate element in the taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18, 19, 20 true 510 Net cash used for financing activities 2 us-gaap_NetCashProvidedByUsedInFinancingActivities us-gaap true debit duration No definition available. false false false false false false false false false false false terselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 9174000 9174 false false false 4 false true false false 8734000 8734 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net cash inflow (outflow) from financing activity for the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 26 false 511 CASH FLOWS FROM INVESTING ACTIVITIES: 2 us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 512 Property additions 2 us-gaap_PaymentsToAcquireProductiveAssets us-gaap true credit duration No definition available. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash outflow for purchases of and capital improvements on property, plant and equipment (capital expenditures), software, and other intangible assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 17 -Subparagraph c false 513 Proceeds from asset sales 2 us-gaap_ProceedsFromSaleOfOtherProductiveAssets us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash inflow from the sale of other tangible or intangible assets used to produce goods or deliver services not otherwise defined in the taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 16 -Subparagraph c false 514 Sales of investment securities held in trusts 2 us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash inflow associated with the sale of debt and equity securities classified as available-for-sale securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 16 -Subparagraph a Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 18 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 16 -Subparagraph b false 515 Purchases of investment securities held in trusts 2 us-gaap_PaymentsToAcquireAvailableForSaleSecurities us-gaap true credit duration No definition available. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash outflow to acquire debt and equity securities not classified as either held-to-maturity securities or trading securities which would be classified as available-for-sale securities and reported at fair value, with unrealized gains and losses excluded from earnings and reported in a separate component of shareholders' equity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 17 -Subparagraph b Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 18 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 17 -Subparagraph a false 516 Loans from associated companies, net 2 us-gaap_ProceedsFromPaymentsForLongTermLoansForRelatedParties us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash inflow or outflow associated with long-term loans for related parties where one party can exercise control or significant influence over another party, including affiliates, owners or officers and their immediate families, pension trusts, and so forth. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15, 16, 17 false 517 Customer acquisition costs 2 us-gaap_PaymentsToAcquireIntangibleAssets us-gaap true credit duration No definition available. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash outflow to acquire asset without physical form usually arising from contractual or other legal rights, excluding goodwill. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 17 -Subparagraph c false 518 Leasehold improvement payments to associated companies 2 fe_LeaseholdImprovementPaymentsToAssociatedCompanies fe false credit duration Leasehold improvement payments to associated companies. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Leasehold improvement payments to associated companies. No authoritative reference available. false 519 Other 2 us-gaap_PaymentsForProceedsFromOtherInvestingActivities us-gaap true credit duration No definition available. false false false false false false false false false false true negatedtotal false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net cash outflow (inflow) from other investing activities. This element is used when there is not a more specific and appropriate element in the taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 true 520 Net cash used for investing activities 2 us-gaap_NetCashProvidedByUsedInInvestingActivities us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net cash inflow (outflow) from investing activity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 26 true 521 Net change in cash and cash equivalents 2 us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease us-gaap true na duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net change between the beginning and ending balance of cash and cash equivalents. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 26 false 522 Cash and cash equivalents at beginning of period 2 us-gaap_CashAndCashEquivalentsAtCarryingValue us-gaap true debit instant No definition available. false false false false false false false false true false false periodstartlabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits should not be reported as cash and cash equivalents. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7, 26 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 8, 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7 -Footnote 1 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 false 523 Cash and cash equivalents at end of period 2 us-gaap_CashAndCashEquivalentsAtCarryingValue us-gaap true debit instant No definition available. false false false false false false false false false true false periodendlabel false 1 false true false false 0 0 false false false 2 false true false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits should not be reported as cash and cash equivalents. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7, 26 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 8, 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7 -Footnote 1 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 false 526 Eliminations [Member] | Affiliates Member 0 na true na na No definition available. false true false false false false false false false false false http://firstenergycorp.com/role/disclosuresupplementalguarantorinformationdetails false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false false 25 USD true false false false Eliminations [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_ConsolidationEliminationsMember dei_LegalEntityAxis explicitMember false false Affiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_AffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 26 USD true false false false Eliminations [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_ConsolidationEliminationsMember dei_LegalEntityAxis explicitMember false false Affiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_AffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 27 USD true false false false Eliminations [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_ConsolidationEliminationsMember dei_LegalEntityAxis explicitMember false false Affiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_AffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 28 USD true false false false Eliminations [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_ConsolidationEliminationsMember dei_LegalEntityAxis explicitMember false false Affiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_AffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ na No definition available. No authoritative reference available. false 529 EXPENSES: 2 us-gaap_CostsAndExpensesAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 531 Purchased power 2 us-gaap_CostOfPurchasedPower us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false -900580000 -900580 false false false 2 false true false false -819640000 -819640 false false false 3 false true false false -1874196000 -1874196 false false false 4 false true false false -1736983000 -1736983 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Cost of electricity purchased and sold during the reporting period. No authoritative reference available. false 631 Eliminations [Member] | Nonaffiliates Member 0 na true na na No definition available. false true false false false false false false false false false http://firstenergycorp.com/role/disclosuresupplementalguarantorinformationdetails false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false false 29 USD true false false false Eliminations [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_ConsolidationEliminationsMember dei_LegalEntityAxis explicitMember false false Nonaffiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_NonaffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 30 USD true false false false Eliminations [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_ConsolidationEliminationsMember dei_LegalEntityAxis explicitMember false false Nonaffiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_NonaffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 31 USD true false false false Eliminations [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_ConsolidationEliminationsMember dei_LegalEntityAxis explicitMember false false Nonaffiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_NonaffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 32 USD true false false false Eliminations [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_ConsolidationEliminationsMember dei_LegalEntityAxis explicitMember false false Nonaffiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_NonaffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ na No definition available. No authoritative reference available. false 634 EXPENSES: 2 us-gaap_CostsAndExpensesAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 636 Purchased power 2 us-gaap_CostOfPurchasedPower us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false true false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Cost of electricity purchased and sold during the reporting period. No authoritative reference available. false 736 Consolidated [Member] 0 na true na na No definition available. false true false false false false false false false false false http://firstenergycorp.com/role/disclosuresupplementalguarantorinformationdetails false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false false 33 USD true false false false Consolidated [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_FesConsolidatedMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 34 USD true false false false Consolidated [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_FesConsolidatedMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 35 USD true false false false Consolidated [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_FesConsolidatedMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 36 USD true false false false Consolidated [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_FesConsolidatedMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 37 USD true false false false Consolidated [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_FesConsolidatedMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ na No definition available. No authoritative reference available. false 737 Condensed Consolidated Statements of Income (Unaudited) 2 us-gaap_IncomeStatementAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 738 Total revenues 2 us-gaap_ElectricUtilityRevenue us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 1314674000 1314674 false false false 2 false true false false 1341152000 1341152 false false false 3 false true false false 2702767000 2702767 false false false 4 false true false false 2567258000 2567258 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The aggregate revenue, whether regulated or unregulated, derived from the generation, transmission and distribution of electricity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 1 -Article 5 true 739 EXPENSES: 2 us-gaap_CostsAndExpensesAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 740 Fuel 2 us-gaap_FuelCosts us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 342411000 342411 false false false 2 false true false false 270309000 270309 false false false 3 false true false false 670632000 670632 false false false 4 false true false false 576467000 576467 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Fuel costs incurred that are directly related to goods produced and sold and services rendered during the reporting period. No authoritative reference available. false 742 Other operating expenses 2 us-gaap_OtherCostAndExpenseOperating us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 303895000 303895 false false false 2 false true false false 278264000 278264 false false false 3 false true false false 608406000 608406 false false false 4 false true false false 585620000 585620 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The total amount of other operating cost and expense items that are associated with the entity's normal revenue producing operation. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 3 -Article 5 false 743 Provision for depreciation 2 us-gaap_DepreciationNonproduction us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 63319000 63319 false false false 2 false true false false 65548000 65548 false false false 3 false true false false 126237000 126237 false false false 4 false true false false 126921000 126921 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The expense recognized in the current period that allocates the cost of nonproduction tangible assets over their useful lives. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 false 746 General taxes 2 us-gaap_TaxesExcludingIncomeAndExciseTaxes us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 22272000 22272 false false false 2 false true false false 21285000 21285 false false false 3 false true false false 49018000 49018 false false false 4 false true false false 44661000 44661 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary All taxes not related to income of the entity or excise or sales taxes levied on the revenue of the entity that are not reported elsewhere. These taxes could include production, real estate, personal property, and pump tax. No authoritative reference available. true 747 Total expenses 2 us-gaap_CostsAndExpenses us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 1099615000 1099615 false false false 2 false true false false 872268000 872268 false false false 3 false true false false 2333179000 2333179 false false false 4 false true false false 1794080000 1794080 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Total costs of sales and operating expenses for the period. No authoritative reference available. true 748 OPERATING INCOME 2 us-gaap_OperatingIncomeLoss us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 215059000 215059 false false false 2 false true false false 468884000 468884 false false false 3 false true false false 369588000 369588 false false false 4 false true false false 773178000 773178 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net result for the period of deducting operating expenses from operating revenues. No authoritative reference available. true 749 OTHER INCOME (EXPENSE): 2 fe_OtherIncomeExpenseAbstract fe false na duration Other Income Expense Abstract. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string Other Income Expense Abstract. false 750 Investment income 2 us-gaap_InvestmentIncomeInterestAndDividend us-gaap true credit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 13366000 13366 false false false 2 false true false false 5643000 5643 false false false 3 false true false false 14083000 14083 false false false 4 false true false false -23231000 -23231 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Income derived from investments in debt and equity securities and on cash and cash equivalents. Interest income represents earnings which reflect the time value of money or transactions in which the payments are for the use or forbearance of money. Dividend income represents a distribution of earnings to shareholders by investee companies. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 14 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 7 -Subparagraph a, b -Article 5 false 751 Miscellaneous income (expense), including 2 fe_Miscellaneousincomeexpenseabstract fe false na duration Miscellaneous income expense Abstact. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string Miscellaneous income expense Abstact. false 752 net income from equity investees 2 us-gaap_SegmentReportingInformationEquityInNetIncomeOfEquityMethodInvesteesOfSegment us-gaap true credit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 4393000 4393 false false false 2 false true false false 7622000 7622 false false false 3 false true false false 5703000 5703 false false false 4 false true false false 10133000 10133 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Amount of income or loss recognized by the reportable segment for its share of an investee's net income or loss reported under the equity method of accounting. Must be disclosed if the amount (a) is included in the measure of segment profit or loss reviewed by the chief operating decision maker or (b) is otherwise regularly provided to the chief operating decision maker, even if not included in that measure of segment profit or loss Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 131 -Paragraph 27 -Subparagraph g false 753 Interest expense to affiliates 2 fe_Interestanddebtexpenseaffiliates fe false debit duration Interest expense to affiliates false false false false false false false false false false true negated false 1 false true false false -2560000 -2560 false false false 2 false true false false -3315000 -3315 false false false 3 false true false false -4865000 -4865 false false false 4 false true false false -6294000 -6294 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Interest expense to affiliates No authoritative reference available. false 754 Interest expense 2 us-gaap_InterestAndDebtExpense us-gaap true debit duration No definition available. false false false false false false false false false false true negated false 1 false true false false -51372000 -51372 false false false 2 false true false false -26271000 -26271 false false false 3 false true false false -101016000 -101016 false false false 4 false true false false -48798000 -48798 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Interest and debt related expenses associated with nonoperating financing activities of the entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 34 -Paragraph 21 false 755 Capitalized interest 2 us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionAdditions us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 23905000 23905 false false false 2 false true false false 14028000 14028 false false false 3 false true false false 43595000 43595 false false false 4 false true false false 24106000 24106 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Total increase in earnings in the period representing the cost of equity (rate of return) and borrowed funds (interest rate) used to finance construction of regulated assets, which is expected to be recovered through rate adjustments. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 71 -Paragraph 15 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 90 -Paragraph 8 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 92 -Paragraph 8, 9, 12 true 756 Total other expense 2 us-gaap_NonoperatingIncomeExpense us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false -12268000 -12268 false false false 2 false true false false -2293000 -2293 false false false 3 false true false false -42500000 -42500 false false false 4 false true false false -44084000 -44084 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The aggregate amount of income (expense) from ancillary business-related activities (that is to say, excluding major activities considered part of the normal operations of the business). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 7 -Article 5 true 757 INCOME BEFORE INCOME TAXES 2 us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments us-gaap true credit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 202791000 202791 false false false 2 false true false false 466591000 466591 false false false 3 false true false false 327088000 327088 false false false 4 false true false false 729094000 729094 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Sum of operating profit and nonoperating income (expense) before income (loss) from equity method investments, income taxes, extraordinary items, cumulative effects of changes in accounting principles, and noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph h -Subparagraph 1(i) -Article 4 false 758 INCOME TAXES 2 us-gaap_IncomeTaxExpenseBenefit us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 68866000 68866 false false false 2 false true false false 169189000 169189 false false false 3 false true false false 113237000 113237 false false false 4 false true false false 261011000 261011 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The sum of the current income tax expense (benefit) and the deferred income tax expense (benefit) pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph h -Article 4 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Paragraph 45 -Subparagraph a, b true 759 NET INCOME 2 us-gaap_ProfitLoss us-gaap true credit duration No definition available. false false false false false false false false false false false terselabel false 1 false true false false 133925000 133925 false false false 2 false true false false 297402000 297402 false false false 3 false true false false 213851000 213851 false false false 4 false true false false 468083000 468083 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph A1, A4, A5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 5 -Subparagraph b Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 29 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph a Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph c(1) false 760 CURRENT ASSETS: 2 us-gaap_AssetsCurrentAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 761 Cash and cash equivalents 2 us-gaap_CashAndCashEquivalentsAtCarryingValue us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 11000 11 false false false 2 false true false false 120034000 120034 false false false 3 false true false false 11000 11 false false false 4 false true false false 120034000 120034 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits should not be reported as cash and cash equivalents. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7, 26 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 8, 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7 -Footnote 1 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 false 762 Receivables 2 us-gaap_ReceivablesNetCurrentAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 763 Customers 2 us-gaap_AccountsReceivableNetCurrent us-gaap true debit instant No definition available. false false false false false false false false false false false terselabel false 1 false true false false 315178000 315178 false false false 2 false false false false 0 0 false false false 3 false true false false 315178000 315178 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 195107000 195107 false false false xbrli:monetaryItemType monetary Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 3 -Subparagraph a(1) -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 4 -Article 5 false 764 Associated companies 2 us-gaap_AccountsReceivableRelatedPartiesCurrent us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 354127000 354127 false false false 2 false false false false 0 0 false false false 3 false true false false 354127000 354127 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 318561000 318561 false false false xbrli:monetaryItemType monetary Amount of receivables arising from transactions with related parties due within one year or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph k -Subparagraph 1 -Article 4 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 57 -Paragraph 2 -Subparagraph d Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 3 -Subparagraph a -Article 5 false 765 Other 2 us-gaap_OtherReceivables us-gaap true debit instant No definition available. false false false false false false false false false false false terselabel false 1 false true false false 36392000 36392 false false false 2 false false false false 0 0 false false false 3 false true false false 36392000 36392 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 51872000 51872 false false false xbrli:monetaryItemType monetary Carrying amounts due as of the balance sheet date from parties or arising from transactions not otherwise specified in the taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 8 -Article 5 false 766 Notes Receivable from associated companies 2 us-gaap_NotesReceivableRelatedPartiesCurrent us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 173931000 173931 false false false 2 false false false false 0 0 false false false 3 false true false false 173931000 173931 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 805103000 805103 false false false xbrli:monetaryItemType monetary Amounts due from parties associated with the reporting entity as evidenced by a written promise to pay, due within 1 year (or 1 business cycle) Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph k -Subparagraph 1 -Article 4 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 57 -Paragraph 2 -Subparagraph d Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 3 -Subparagraph a -Article 5 false 767 Materials and supplies, at average cost 2 us-gaap_InventoryNet us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 578521000 578521 false false false 2 false false false false 0 0 false false false 3 false true false false 578521000 578521 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 539541000 539541 false false false xbrli:monetaryItemType monetary Carrying amount (lower of cost or market) as of the balance sheet date of inventories less all valuation and other allowances. Excludes noncurrent inventory balances (expected to remain on hand past one year or one operating cycle, if longer). No authoritative reference available. false 768 Prepayments and other 2 us-gaap_OtherAssetsCurrent us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 172514000 172514 false false false 2 false false false false 0 0 false false false 3 false true false false 172514000 172514 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 107782000 107782 false false false xbrli:monetaryItemType monetary Aggregate carrying amount, as of the balance sheet date, of current assets not separately presented elsewhere in the balance sheet. Current assets are expected to be realized or consumed within one year (or the normal operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 8 -Article 5 false 769 Total current assets 2 us-gaap_AssetsCurrent us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 1630674000 1630674 false false false 2 false false false false 0 0 false false false 3 false true false false 1630674000 1630674 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 2017978000 2017978 false false false xbrli:monetaryItemType monetary Sum of the carrying amounts as of the balance sheet date of all assets that are expected to be realized in cash, sold, or consumed within one year (or the normal operating cycle, if longer). Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 9 -Article 5 true 770 PROPERTY, PLANT AND EQUIPMENT: 2 us-gaap_PropertyPlantAndEquipmentNetAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 771 In service 2 us-gaap_PropertyPlantAndEquipmentGross us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 10500405000 10500405 false false false 2 false false false false 0 0 false false false 3 false true false false 10500405000 10500405 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 10357632000 10357632 false false false xbrli:monetaryItemType monetary Carrying amount at the balance sheet date for long-lived physical assets used in the normal conduct of business and not intended for resale. This can include land, physical structures, machinery, vehicles, furniture, computer equipment, construction in progress, and similar items. Amount does not include depreciation. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 false 772 Less - Accumulated provision for depreciation 2 us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 4695180000 4695180 false false false 2 false false false false 0 0 false false false 3 false true false false 4695180000 4695180 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 4531158000 4531158 false false false xbrli:monetaryItemType monetary The cumulative amount of depreciation, depletion and amortization (related to property, plant and equipment, but not including land) that has been recognized in the income statement. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 -Subparagraph c Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 14 -Article 5 true 773 Total in service, net of accumulated depreciation 2 fe_NetPlantExcludingConstructionWorkInProgress fe false debit instant Net Plant Excluding Construction Work In Progress. false false false false false false false false false false false verboselabel false 1 false true false false 5805225000 5805225 false false false 2 false false false false 0 0 false false false 3 false true false false 5805225000 5805225 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 5826474000 5826474 false false false xbrli:monetaryItemType monetary Net Plant Excluding Construction Work In Progress. No authoritative reference available. false 774 Construction work in progress 2 us-gaap_ConstructionInProgressGross us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 2622865000 2622865 false false false 2 false false false false 0 0 false false false 3 false true false false 2622865000 2622865 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 2423446000 2423446 false false false xbrli:monetaryItemType monetary Carrying amount at the balance sheet date of long-lived asset under construction that include construction costs to date on capital projects that have not been completed and assets being constructed that are not ready to be placed into service. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 true 775 Total property, plant and equipment 2 us-gaap_PropertyPlantAndEquipmentNet us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 8428090000 8428090 false false false 2 false false false false 0 0 false false false 3 false true false false 8428090000 8428090 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 8249920000 8249920 false false false xbrli:monetaryItemType monetary Tangible assets that are held by an entity for use in the production or supply of goods and services, for rental to others, or for administrative purposes and that are expected to provide economic benefit for more than one year; net of accumulated depreciation. Examples include land, buildings, and production equipment. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 13 -Subparagraph a -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 12 -Paragraph 5 -Subparagraph b, c Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 8 -Article 7 true 776 INVESTMENTS: 2 us-gaap_InvestmentsAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 777 Nuclear plant decommissioning trusts 2 us-gaap_DecommissioningFundInvestments us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 1107594000 1107594 false false false 2 false false false false 0 0 false false false 3 false true false false 1107594000 1107594 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 1088641000 1088641 false false false xbrli:monetaryItemType monetary Decommission fund to pay for the costs of decontaminating and decommissioning of facilities through collection of revenues derived from utility assessments and government appropriations. Decommission fund investment for the process whereby a power station, at the end of its economic life, is taken permanently out of service and its site made available for other purposes. In the case of a nuclear station this comprises three different states of clearance. Immediately after the final closure, radioactive material such as nuclear fuel and operational waste is removed and the buildings surrounding the reactor shield are dismantled and finally the reactor itself is dismantled. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 12 -Article 5 false 778 Investment in associated companies 2 fe_Investmentinassociatedcompanies fe false debit instant Investment in associated companies. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Investment in associated companies. No authoritative reference available. false 779 Other 2 us-gaap_OtherLongTermInvestments us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 7965000 7965 false false false 2 false false false false 0 0 false false false 3 false true false false 7965000 7965 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 22466000 22466 false false false xbrli:monetaryItemType monetary Other noncurrent investments not otherwise specified in the taxonomy, not including investments in marketable securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 12 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 1 -Subparagraph f -Article 7 true 780 Total investments 2 us-gaap_LongTermInvestments us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 1115559000 1115559 false false false 2 false false false false 0 0 false false false 3 false true false false 1115559000 1115559 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 1111107000 1111107 false false false xbrli:monetaryItemType monetary The total amount of investments that are intended to be held for an extended period of time (longer than one operating cycle). No authoritative reference available. true 781 DEFERRED CHARGES AND OTHER ASSETS: 2 fe_DeferredChargesAndOtherAssetsAbstract fe false na duration Deferred Charges And Other Assets Abstract. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string Deferred Charges And Other Assets Abstract. false 782 Accumulated deferred income taxes 2 us-gaap_DeferredTaxAssetsDeferredIncome us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 86626000 86626 false false false xbrli:monetaryItemType monetary The tax effect as of the balance sheet date of the amount of the estimated future tax deductions attributable to income recognized only for tax purposes and which will reverse when recognized under generally accepted accounting principles. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Paragraph 43 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Paragraph 11 -Subparagraph c false 783 Goodwill 2 us-gaap_Goodwill us-gaap true debit instant No definition available. false false false false false false false false false false false false 1 false true false false 24248000 24248 false false false 2 false false false false 0 0 false false false 3 false true false false 24248000 24248 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 24248000 24248 false false false xbrli:monetaryItemType monetary Carrying amount as of the balance sheet date, which is the cumulative amount paid, adjusted for any amortization recognized prior to adoption of FAS 142 and for any impairment charges, in excess of the fair value of net assets acquired in one or more business combination transactions. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 142 -Paragraph 43 false 784 Customer intangibles 2 us-gaap_FiniteLivedIntangibleAssetsNet us-gaap true debit instant No definition available. false false false false false false false false false false false false 1 false true false false 118219000 118219 false false false 2 false false false false 0 0 false false false 3 false true false false 118219000 118219 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 16566000 16566 false false false xbrli:monetaryItemType monetary The aggregate sum of gross carrying value of a major finite-lived intangible asset class, less accumulated amortization and any impairment charges. A major class is composed of intangible assets that can be grouped together because they are similar, either by their nature or by their use in the operations of a company. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 142 -Paragraph 45 -Subparagraph a(1) false 785 Property taxes 2 fe_PropertyTaxes fe false debit instant Property taxes. false false false false false false false false false false false verboselabel false 1 false true false false 50125000 50125 false false false 2 false false false false 0 0 false false false 3 false true false false 50125000 50125 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 50125000 50125 false false false xbrli:monetaryItemType monetary Property taxes. No authoritative reference available. false 786 Unamortized sale and leaseback costs 2 fe_UnamortizedSaleAndLeasebackCosts fe false debit instant Unamortized sale and leaseback costs. false false false false false false false false false false false verboselabel false 1 false true false false 77646000 77646 false false false 2 false false false false 0 0 false false false 3 false true false false 77646000 77646 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 72553000 72553 false false false xbrli:monetaryItemType monetary Unamortized sale and leaseback costs. No authoritative reference available. false 787 Other 2 us-gaap_OtherAssetsNoncurrent us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 128315000 128315 false false false 2 false false false false 0 0 false false false 3 false true false false 128315000 128315 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 121665000 121665 false false false xbrli:monetaryItemType monetary Aggregate carrying amount, as of the balance sheet date, of noncurrent assets not separately disclosed in the balance sheet due to materiality considerations. Noncurrent assets are expected to be realized or consumed after one year (or the normal operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 17 -Article 5 true 788 Total deferred charges and other assets 2 us-gaap_AssetsNoncurrent us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 398553000 398553 false false false 2 false false false false 0 0 false false false 3 false true false false 398553000 398553 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 371783000 371783 false false false xbrli:monetaryItemType monetary Sum of the carrying amounts as of the balance sheet date of all assets that are expected to be realized in cash, sold or consumed after one year or beyond the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 18 -Article 5 true 789 Total assets 2 us-gaap_Assets us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 11572876000 11572876 false false false 2 false false false false 0 0 false false false 3 false true false false 11572876000 11572876 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 11750788000 11750788 false false false xbrli:monetaryItemType monetary Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Concepts (CON) -Number 6 -Paragraph 25 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 18 -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 12 -Article 7 true 790 CURRENT LIABILITIES: 2 us-gaap_LiabilitiesCurrentAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 791 Currently payable long-term debt 2 us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 1381783000 1381783 false false false 2 false false false false 0 0 false false false 3 false true false false 1381783000 1381783 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 1550927000 1550927 false false false xbrli:monetaryItemType monetary Obligation related to long-term debt (excluding convertible debt) and capital leases, the portion which is due in one year or less in the future. No authoritative reference available. false 792 Short-term borrowings- 2 us-gaap_ShortTermBorrowingsAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 793 Associated companies 2 us-gaap_ShortTermNonBankLoansAndNotesPayable us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 85128000 85128 false false false 2 false false false false 0 0 false false false 3 false true false false 85128000 85128 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 9237000 9237 false false false xbrli:monetaryItemType monetary Carrying amount at the balance sheet date of borrowings from a creditor other than a bank, not elsewhere specified in the taxonomy, with a maturity within one year (or within one operating cycle if longer) from the date of borrowing. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19 -Subparagraph a -Article 5 false 794 Other 2 us-gaap_ShortTermBorrowings us-gaap true credit instant No definition available. false false false false false false false false false false false terselabel false 1 false true false false 100000000 100000 false false false 2 false false false false 0 0 false false false 3 false true false false 100000000 100000 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 100000000 100000 false false false xbrli:monetaryItemType monetary Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19 -Subparagraph a -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 13 -Subparagraph 2, 3 -Article 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 16 -Subparagraph a(1) -Article 7 false 795 Accounts payable- 2 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 796 Associated companies 2 us-gaap_AccountsPayableRelatedPartiesCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 412507000 412507 false false false 2 false false false false 0 0 false false false 3 false true false false 412507000 412507 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 466078000 466078 false false false xbrli:monetaryItemType monetary Amount for accounts payable to related parties. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19 -Subparagraph a -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 57 -Paragraph 2 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph k -Subparagraph 1 -Article 4 false 797 Other 2 us-gaap_AccountsPayableCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false terselabel false 1 false true false false 236720000 236720 false false false 2 false false false false 0 0 false false false 3 false true false false 236720000 236720 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 245363000 245363 false false false xbrli:monetaryItemType monetary Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19 -Subparagraph a -Article 5 false 798 Accrued taxes 2 us-gaap_AccruedIncomeTaxesCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 109082000 109082 false false false 2 false false false false 0 0 false false false 3 false true false false 109082000 109082 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 83158000 83158 false false false xbrli:monetaryItemType monetary Carrying amount as of the balance sheet date of the unpaid sum of the known and estimated amounts payable to satisfy all currently due domestic and foreign income tax obligations. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 15 -Subparagraph b(1) -Article 7 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 15 -Article 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20 -Article 5 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Interpretation (FIN) -Number 48 -Paragraph 15, 21 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Section Appendix E -Paragraph 289 false 799 Other 2 us-gaap_OtherLiabilitiesCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 369086000 369086 false false false 2 false false false false 0 0 false false false 3 false true false false 369086000 369086 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 359057000 359057 false false false xbrli:monetaryItemType monetary Aggregate carrying amount, as of the balance sheet date, of current obligations not separately disclosed in the balance sheet due to materiality considerations. Current liabilities are expected to be paid within one year (or the normal operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 43 -Chapter 3 -Section A -Paragraph 8 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 6 -Paragraph 15 true 800 Total current liabilities 2 us-gaap_LiabilitiesCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 2694306000 2694306 false false false 2 false false false false 0 0 false false false 3 false true false false 2694306000 2694306 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 2813820000 2813820 false false false xbrli:monetaryItemType monetary Total obligations incurred as part of normal operations that are expected to be paid during the following twelve months or within one business cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 21 -Article 5 true 801 CAPITALIZATION: 2 us-gaap_CapitalizationLongtermDebtAndEquityAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 802 Common stockholder's equity 2 us-gaap_StockholdersEquity us-gaap true credit instant No definition available. false false false false false false false false false false false terselabel false 1 false true false false 3731382000 3731382 false false false 2 false false false false 0 0 false false false 3 false true false false 3731382000 3731382 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 3514571000 3514571 false false false xbrli:monetaryItemType monetary Total of all Stockholders' Equity (deficit) items, net of receivables from officers, directors owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph A3 -Appendix A Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 4 -Section E Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29, 30, 31 -Article 5 false 803 Long-term debt and other long-term obligations 2 us-gaap_LongTermDebtAndCapitalLeaseObligations us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 2585919000 2585919 false false false 2 false false false false 0 0 false false false 3 false true false false 2585919000 2585919 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 2711652000 2711652 false false false xbrli:monetaryItemType monetary Sum of the carrying values as of the balance sheet date of all long-term debt, which is debt initially having maturities due after one year from the balance sheet date or beyond the operating cycle, if longer, but excluding the portions thereof scheduled to be repaid within one year or the normal operating cycle, if longer plus capital lease obligations due to be paid more than one year after the balance sheet date. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 6 -Section H true 804 Total capitalization 2 fe_TotalCapitalization fe false credit instant Total Capitalization. false false false false false false false false false false false totallabel false 1 false true false false 6317301000 6317301 false false false 2 false false false false 0 0 false false false 3 false true false false 6317301000 6317301 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 6226223000 6226223 false false false xbrli:monetaryItemType monetary Total Capitalization. No authoritative reference available. true 805 NONCURRENT LIABILITIES: 2 us-gaap_LiabilitiesNoncurrentAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 806 Deferred gain on sale and leaseback transaction 2 us-gaap_SaleLeasebackTransactionDeferredGainNet us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 976012000 976012 false false false 2 false false false false 0 0 false false false 3 false true false false 976012000 976012 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 992869000 992869 false false false xbrli:monetaryItemType monetary The portion of the gain that will be recorded as income or a reduction in rent expense in future periods less amounts recognized in the current period. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 13 -Paragraph 33 false 807 Accumulated deferred income taxes 2 us-gaap_DeferredTaxLiabilitiesNoncurrent us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 9995000 9995 false false false 2 false false false false 0 0 false false false 3 false true false false 9995000 9995 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Represents the noncurrent portion of deferred tax liabilities, which result from applying the applicable tax rate to net taxable temporary differences pertaining to each jurisdiction to which the entity is obligated to pay income tax. A noncurrent taxable temporary difference is a difference between the tax basis and the carrying amount of a noncurrent asset or liability in the financial statements prepared in accordance with generally accepted accounting principles. In a classified statement of financial position, an enterprise shall separate deferred tax liabilities and assets into a current amount and a noncurrent amount. Deferred tax liabilities and assets shall be classified as current or noncurrent based on the classification of the related asset or liability for financial reporting. A deferred tax liability or asset that is not related to an asset or liability for financial reporting, including deferred tax assets related to carryforwards, shall be classified according to the expected reversal date of the temporary difference. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Paragraph 41, 42 false 808 Accumulated deferred investment tax credits 2 us-gaap_AccumulatedDeferredInvestmentTaxCredit us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 56310000 56310 false false false 2 false false false false 0 0 false false false 3 false true false false 56310000 56310 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 58396000 58396 false false false xbrli:monetaryItemType monetary The noncurrent portion of the reserve for accumulated deferred investment tax credits as of the balance sheet date. This is the remaining investment credit, which will reduce the cost of services collected from ratepayers by a ratable portion over the investment's regulatory life. No authoritative reference available. false 809 Asset retirement obligations 2 us-gaap_AssetRetirementObligationsNoncurrent us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 863409000 863409 false false false 2 false false false false 0 0 false false false 3 false true false false 863409000 863409 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 921448000 921448 false false false xbrli:monetaryItemType monetary Noncurrent portion of the carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 143 -Paragraph 3, 10, 22 false 810 Retirement benefits 2 us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansNoncurrentLiabilities us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 223853000 223853 false false false 2 false false false false 0 0 false false false 3 false true false false 223853000 223853 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 204035000 204035 false false false xbrli:monetaryItemType monetary For classified balance sheets this represents the noncurrent liability for underfunded plans recognized in the balance sheet that is associated with the defined benefit pension plans and other postretirement defined benefit plans. For unclassified balance sheets, this represents the entire liability recognized in the balance sheet that is associated with the defined benefit plans. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph c Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 6 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 3 false 811 Property taxes 2 fe_PropertyTaxesNoncurrentLiabilities fe false credit instant Property taxes. false false false false false false false false false false false verboselabel false 1 false true false false 50125000 50125 false false false 2 false false false false 0 0 false false false 3 false true false false 50125000 50125 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 50125000 50125 false false false xbrli:monetaryItemType monetary Property taxes. No authoritative reference available. false 812 Lease market valuation liability 2 us-gaap_OffMarketLeaseUnfavorable us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 239447000 239447 false false false 2 false false false false 0 0 false false false 3 false true false false 239447000 239447 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 262200000 262200 false false false xbrli:monetaryItemType monetary This element represents a liability associated with the acquisition of an off-market lease when the terms of the lease are unfavorable to the market terms for the lease at the date of acquisition. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141 -Paragraph 37 false 813 Other 2 us-gaap_OtherLiabilitiesNoncurrent us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 142118000 142118 false false false 2 false false false false 0 0 false false false 3 false true false false 142118000 142118 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 221672000 221672 false false false xbrli:monetaryItemType monetary Aggregate carrying amount, as of the balance sheet date, of noncurrent obligations not separately disclosed in the balance sheet due to materiality considerations. Noncurrent liabilities are expected to be paid after one year (or the normal operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 24 -Article 5 true 814 Total noncurrent liabilities 2 us-gaap_LiabilitiesNoncurrent us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 2561269000 2561269 false false false 2 false false false false 0 0 false false false 3 false true false false 2561269000 2561269 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 2710745000 2710745 false false false xbrli:monetaryItemType monetary Total obligations incurred as part of normal operations that is expected to be repaid beyond the following twelve months or one business cycle. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22, 23, 24, 25, 26, 27 -Article 5 true 815 Total liabilities and capitalization 2 us-gaap_LiabilitiesAndStockholdersEquity us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 11572876000 11572876 false false false 2 false false false false 0 0 false false false 3 false true false false 11572876000 11572876 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 11750788000 11750788 false false false xbrli:monetaryItemType monetary Total of all Liabilities and Stockholders' Equity items. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 32 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 25 -Article 7 true 816 Statements of Cash Flows [Abstract] 2 us-gaap_StatementOfCashFlowsAbstract us-gaap true na duration No definition available. false false false false false true false false false false false false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 817 NET CASH PROVIDED FROM (USED FOR) OPERATING ACTIVITIES 2 us-gaap_NetCashProvidedByUsedInOperatingActivities us-gaap true na duration No definition available. false false false false false false false false false false false terselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 218455000 218455 false false false 4 false true false false 812216000 812216 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net cash from (used in) all of the entity's operating activities, including those of discontinued operations, of the reporting entity. Operating activities generally involve producing and delivering goods and providing services. Operating activity cash flows include transactions, adjustments, and changes in value that are not defined as investing or financing activities. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 26 false 818 New Financing- 2 fe_NewFinancingAbstract fe false na duration New Financing Abstract. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string New Financing Abstract. false 819 Long-term debt 2 us-gaap_ProceedsFromIssuanceOfLongTermDebt us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false true false false 681675000 681675 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 19 -Subparagraph b false 820 Short-term borrowings, net 2 us-gaap_ProceedsFromShortTermDebt us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 75891000 75891 false false false 4 false true false false 145009000 145009 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash inflow from a borrowing having initial term of repayment within one year or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 19 -Subparagraph b false 821 Redemptions and Repayments- 2 fe_RedemptionsAndRepaymentsAbstract fe false na duration Redemptions And Repayments Abstract. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string Redemptions And Repayments Abstract. false 822 Long-term debt 2 us-gaap_RepaymentsOfLongTermDebt us-gaap true credit duration No definition available. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -295037000 -295037 false false false 4 false true false false -622853000 -622853 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 20 -Subparagraph b false 823 Short-term borrowings, net 2 us-gaap_RepaymentsOfShortTermDebt us-gaap true credit duration No definition available. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash outflow for a borrowing having initial term of repayment within one year or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 20 -Subparagraph b false 824 Other 2 us-gaap_ProceedsFromPaymentsForOtherFinancingActivities us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -686000 -686 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net cash inflow (outflow) from other financing activities. This element is used when there is not a more specific and appropriate element in the taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18, 19, 20 true 825 Net cash used for financing activities 2 us-gaap_NetCashProvidedByUsedInFinancingActivities us-gaap true debit duration No definition available. false false false false false false false false false false false terselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -219832000 -219832 false false false 4 false true false false 203831000 203831 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net cash inflow (outflow) from financing activity for the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 26 false 826 CASH FLOWS FROM INVESTING ACTIVITIES: 2 us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 827 Property additions 2 us-gaap_PaymentsToAcquireProductiveAssets us-gaap true credit duration No definition available. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -566187000 -566187 false false false 4 false true false false -634967000 -634967 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash outflow for purchases of and capital improvements on property, plant and equipment (capital expenditures), software, and other intangible assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 17 -Subparagraph c false 828 Proceeds from asset sales 2 us-gaap_ProceedsFromSaleOfOtherProductiveAssets us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 115657000 115657 false false false 4 false true false false 15771000 15771 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash inflow from the sale of other tangible or intangible assets used to produce goods or deliver services not otherwise defined in the taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 16 -Subparagraph c false 829 Sales of investment securities held in trusts 2 us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 956813000 956813 false false false 4 false true false false 537078000 537078 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash inflow associated with the sale of debt and equity securities classified as available-for-sale securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 16 -Subparagraph a Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 18 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 16 -Subparagraph b false 830 Purchases of investment securities held in trusts 2 us-gaap_PaymentsToAcquireAvailableForSaleSecurities us-gaap true credit duration No definition available. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -978785000 -978785 false false false 4 false true false false -550730000 -550730 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash outflow to acquire debt and equity securities not classified as either held-to-maturity securities or trading securities which would be classified as available-for-sale securities and reported at fair value, with unrealized gains and losses excluded from earnings and reported in a separate component of shareholders' equity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 17 -Subparagraph b Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 18 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 17 -Subparagraph a false 831 Loans from associated companies, net 2 us-gaap_ProceedsFromPaymentsForLongTermLoansForRelatedParties us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 631173000 631173 false false false 4 false true false false -241170000 -241170 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash inflow or outflow associated with long-term loans for related parties where one party can exercise control or significant influence over another party, including affiliates, owners or officers and their immediate families, pension trusts, and so forth. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15, 16, 17 false 832 Customer acquisition costs 2 us-gaap_PaymentsToAcquireIntangibleAssets us-gaap true credit duration No definition available. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -104795000 -104795 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash outflow to acquire asset without physical form usually arising from contractual or other legal rights, excluding goodwill. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 17 -Subparagraph c false 833 Leasehold improvement payments to associated companies 2 fe_LeaseholdImprovementPaymentsToAssociatedCompanies fe false credit duration Leasehold improvement payments to associated companies. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -51204000 -51204 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Leasehold improvement payments to associated companies. No authoritative reference available. false 834 Other 2 us-gaap_PaymentsForProceedsFromOtherInvestingActivities us-gaap true credit duration No definition available. false false false false false false false false false false true negatedtotal false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -1296000 -1296 false false false 4 false true false false -22034000 -22034 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net cash outflow (inflow) from other investing activities. This element is used when there is not a more specific and appropriate element in the taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 true 835 Net cash used for investing activities 2 us-gaap_NetCashProvidedByUsedInInvestingActivities us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 1376000 1376 false false false 4 false true false false -896052000 -896052 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net cash inflow (outflow) from investing activity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 26 true 836 Net change in cash and cash equivalents 2 us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease us-gaap true na duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -1000 -1 false false false 4 false true false false 119995000 119995 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net change between the beginning and ending balance of cash and cash equivalents. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 26 false 837 Cash and cash equivalents at beginning of period 2 us-gaap_CashAndCashEquivalentsAtCarryingValue us-gaap true debit instant No definition available. false false false false false false false false true false false periodstartlabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 12000 12 false false false 4 false true false false 39000 39 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits should not be reported as cash and cash equivalents. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7, 26 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 8, 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7 -Footnote 1 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 false 838 Cash and cash equivalents at end of period 2 us-gaap_CashAndCashEquivalentsAtCarryingValue us-gaap true debit instant No definition available. false false false false false false false false false true false periodendlabel false 1 false true false false 11000 11 false false false 2 false true false false 120034000 120034 false false false 3 false true false false 11000 11 false false false 4 false true false false 120034000 120034 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits should not be reported as cash and cash equivalents. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7, 26 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 8, 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7 -Footnote 1 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 false 841 Consolidated [Member] | Affiliates Member 0 na true na na No definition available. false true false false false false false false false false false http://firstenergycorp.com/role/disclosuresupplementalguarantorinformationdetails false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false false 38 USD true false false false Consolidated [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_FesConsolidatedMember dei_LegalEntityAxis explicitMember false false Affiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_AffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 39 USD true false false false Consolidated [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_FesConsolidatedMember dei_LegalEntityAxis explicitMember false false Affiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_AffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 40 USD true false false false Consolidated [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_FesConsolidatedMember dei_LegalEntityAxis explicitMember false false Affiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_AffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 41 USD true false false false Consolidated [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_FesConsolidatedMember dei_LegalEntityAxis explicitMember false false Affiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_AffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ na No definition available. No authoritative reference available. false 844 EXPENSES: 2 us-gaap_CostsAndExpensesAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 846 Purchased power 2 us-gaap_CostOfPurchasedPower us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 68898000 68898 false false false 2 false true false false 51249000 51249 false false false 3 false true false false 129851000 129851 false false false 4 false true false false 114456000 114456 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Cost of electricity purchased and sold during the reporting period. No authoritative reference available. false 946 Consolidated [Member] | Nonaffiliates Member 0 na true na na No definition available. false true false false false false false false false false false http://firstenergycorp.com/role/disclosuresupplementalguarantorinformationdetails false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false false 42 USD true false false false Consolidated [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_FesConsolidatedMember dei_LegalEntityAxis explicitMember false false Nonaffiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_NonaffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 43 USD true false false false Consolidated [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_FesConsolidatedMember dei_LegalEntityAxis explicitMember false false Nonaffiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_NonaffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 44 USD true false false false Consolidated [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_FesConsolidatedMember dei_LegalEntityAxis explicitMember false false Nonaffiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_NonaffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 45 USD true false false false Consolidated [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_FesConsolidatedMember dei_LegalEntityAxis explicitMember false false Nonaffiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_NonaffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ na No definition available. No authoritative reference available. false 949 EXPENSES: 2 us-gaap_CostsAndExpensesAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 951 Purchased power 2 us-gaap_CostOfPurchasedPower us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 298820000 298820 false false false 2 false true false false 185613000 185613 false false false 3 false true false false 749035000 749035 false false false 4 false true false false 345955000 345955 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Cost of electricity purchased and sold during the reporting period. No authoritative reference available. false 1051 FGCO [ Member] 0 na true na na No definition available. false true false false false false false false false false false http://firstenergycorp.com/role/disclosuresupplementalguarantorinformationdetails false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false false 46 USD true false false false FGCO [ Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_NonGuarantorSubsidiariesMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 47 USD true false false false FGCO [ Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_NonGuarantorSubsidiariesMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 48 USD true false false false FGCO [ Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_NonGuarantorSubsidiariesMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 49 USD true false false false FGCO [ Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_NonGuarantorSubsidiariesMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 50 USD true false false false FGCO [ Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_NonGuarantorSubsidiariesMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ na No definition available. No authoritative reference available. false 1052 Condensed Consolidated Statements of Income (Unaudited) 2 us-gaap_IncomeStatementAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 1053 Total revenues 2 us-gaap_ElectricUtilityRevenue us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 580621000 580621 false false false 2 false true false false 703110000 703110 false false false 3 false true false false 1148985000 1148985 false false false 4 false true false false 1249036000 1249036 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The aggregate revenue, whether regulated or unregulated, derived from the generation, transmission and distribution of electricity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 1 -Article 5 true 1054 EXPENSES: 2 us-gaap_CostsAndExpensesAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 1055 Fuel 2 us-gaap_FuelCosts us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 300867000 300867 false false false 2 false true false false 238832000 238832 false false false 3 false true false false 581730000 581730 false false false 4 false true false false 513679000 513679 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Fuel costs incurred that are directly related to goods produced and sold and services rendered during the reporting period. No authoritative reference available. false 1057 Other operating expenses 2 us-gaap_OtherCostAndExpenseOperating us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 94373000 94373 false false false 2 false true false false 99145000 99145 false false false 3 false true false false 194149000 194149 false false false 4 false true false false 203588000 203588 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The total amount of other operating cost and expense items that are associated with the entity's normal revenue producing operation. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 3 -Article 5 false 1058 Provision for depreciation 2 us-gaap_DepreciationNonproduction us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 27466000 27466 false false false 2 false true false false 30191000 30191 false false false 3 false true false false 53993000 53993 false false false 4 false true false false 60211000 60211 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The expense recognized in the current period that allocates the cost of nonproduction tangible assets over their useful lives. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 false 1061 General taxes 2 us-gaap_TaxesExcludingIncomeAndExciseTaxes us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 9227000 9227 false false false 2 false true false false 11332000 11332 false false false 3 false true false false 23827000 23827 false false false 4 false true false false 23958000 23958 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary All taxes not related to income of the entity or excise or sales taxes levied on the revenue of the entity that are not reported elsewhere. These taxes could include production, real estate, personal property, and pump tax. No authoritative reference available. true 1062 Total expenses 2 us-gaap_CostsAndExpenses us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 439096000 439096 false false false 2 false true false false 384518000 384518 false false false 3 false true false false 865941000 865941 false false false 4 false true false false 808536000 808536 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Total costs of sales and operating expenses for the period. No authoritative reference available. true 1063 OPERATING INCOME 2 us-gaap_OperatingIncomeLoss us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 141525000 141525 false false false 2 false true false false 318592000 318592 false false false 3 false true false false 283044000 283044 false false false 4 false true false false 440500000 440500 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net result for the period of deducting operating expenses from operating revenues. No authoritative reference available. true 1064 OTHER INCOME (EXPENSE): 2 fe_OtherIncomeExpenseAbstract fe false na duration Other Income Expense Abstract. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string Other Income Expense Abstract. false 1065 Investment income 2 us-gaap_InvestmentIncomeInterestAndDividend us-gaap true credit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 81000 81 false false false 2 false true false false 131000 131 false false false 3 false true false false 135000 135 false false false 4 false true false false 162000 162 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Income derived from investments in debt and equity securities and on cash and cash equivalents. Interest income represents earnings which reflect the time value of money or transactions in which the payments are for the use or forbearance of money. Dividend income represents a distribution of earnings to shareholders by investee companies. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 14 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 7 -Subparagraph a, b -Article 5 false 1066 Miscellaneous income (expense), including 2 fe_Miscellaneousincomeexpenseabstract fe false na duration Miscellaneous income expense Abstact. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string Miscellaneous income expense Abstact. false 1067 net income from equity investees 2 us-gaap_SegmentReportingInformationEquityInNetIncomeOfEquityMethodInvesteesOfSegment us-gaap true credit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 709000 709 false false false 2 false true false false 820000 820 false false false 3 false true false false -924000 -924 false false false 4 false true false false 742000 742 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Amount of income or loss recognized by the reportable segment for its share of an investee's net income or loss reported under the equity method of accounting. Must be disclosed if the amount (a) is included in the measure of segment profit or loss reviewed by the chief operating decision maker or (b) is otherwise regularly provided to the chief operating decision maker, even if not included in that measure of segment profit or loss Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 131 -Paragraph 27 -Subparagraph g false 1068 Interest expense to affiliates 2 fe_Interestanddebtexpenseaffiliates fe false debit duration Interest expense to affiliates false false false false false false false false false false true negated false 1 false true false false -2084000 -2084 false false false 2 false true false false -1623000 -1623 false false false 3 false true false false -3896000 -3896 false false false 4 false true false false -3381000 -3381 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Interest expense to affiliates No authoritative reference available. false 1069 Interest expense 2 us-gaap_InterestAndDebtExpense us-gaap true debit duration No definition available. false false false false false false false false false false true negated false 1 false true false false -27799000 -27799 false false false 2 false true false false -24967000 -24967 false false false 3 false true false false -54305000 -54305 false false false 4 false true false false -46025000 -46025 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Interest and debt related expenses associated with nonoperating financing activities of the entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 34 -Paragraph 21 false 1070 Capitalized interest 2 us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionAdditions us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 19573000 19573 false false false 2 false true false false 11126000 11126 false false false 3 false true false false 35906000 35906 false false false 4 false true false false 18876000 18876 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Total increase in earnings in the period representing the cost of equity (rate of return) and borrowed funds (interest rate) used to finance construction of regulated assets, which is expected to be recovered through rate adjustments. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 71 -Paragraph 15 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 90 -Paragraph 8 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 92 -Paragraph 8, 9, 12 true 1071 Total other expense 2 us-gaap_NonoperatingIncomeExpense us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false -9520000 -9520 false false false 2 false true false false -14513000 -14513 false false false 3 false true false false -23084000 -23084 false false false 4 false true false false -29626000 -29626 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The aggregate amount of income (expense) from ancillary business-related activities (that is to say, excluding major activities considered part of the normal operations of the business). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 7 -Article 5 true 1072 INCOME BEFORE INCOME TAXES 2 us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments us-gaap true credit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 132005000 132005 false false false 2 false true false false 304079000 304079 false false false 3 false true false false 259960000 259960 false false false 4 false true false false 410874000 410874 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Sum of operating profit and nonoperating income (expense) before income (loss) from equity method investments, income taxes, extraordinary items, cumulative effects of changes in accounting principles, and noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph h -Subparagraph 1(i) -Article 4 false 1073 INCOME TAXES 2 us-gaap_IncomeTaxExpenseBenefit us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 48465000 48465 false false false 2 false true false false 108114000 108114 false false false 3 false true false false 96508000 96508 false false false 4 false true false false 147256000 147256 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The sum of the current income tax expense (benefit) and the deferred income tax expense (benefit) pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph h -Article 4 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Paragraph 45 -Subparagraph a, b true 1074 NET INCOME 2 us-gaap_ProfitLoss us-gaap true credit duration No definition available. false false false false false false false false false false false terselabel false 1 false true false false 83540000 83540 false false false 2 false true false false 195965000 195965 false false false 3 false true false false 163452000 163452 false false false 4 false true false false 263618000 263618 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph A1, A4, A5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 5 -Subparagraph b Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 29 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph a Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph c(1) false 1075 CURRENT ASSETS: 2 us-gaap_AssetsCurrentAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 1076 Cash and cash equivalents 2 us-gaap_CashAndCashEquivalentsAtCarryingValue us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 2000 2 false false false 2 false true false false 34000 34 false false false 3 false true false false 2000 2 false false false 4 false true false false 34000 34 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits should not be reported as cash and cash equivalents. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7, 26 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 8, 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7 -Footnote 1 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 false 1077 Receivables 2 us-gaap_ReceivablesNetCurrentAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 1078 Customers 2 us-gaap_AccountsReceivableNetCurrent us-gaap true debit instant No definition available. false false false false false false false false false false false terselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 3 -Subparagraph a(1) -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 4 -Article 5 false 1079 Associated companies 2 us-gaap_AccountsReceivableRelatedPartiesCurrent us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 257268000 257268 false false false 2 false false false false 0 0 false false false 3 false true false false 257268000 257268 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 175730000 175730 false false false xbrli:monetaryItemType monetary Amount of receivables arising from transactions with related parties due within one year or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph k -Subparagraph 1 -Article 4 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 57 -Paragraph 2 -Subparagraph d Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 3 -Subparagraph a -Article 5 false 1080 Other 2 us-gaap_OtherReceivables us-gaap true debit instant No definition available. false false false false false false false false false false false terselabel false 1 false true false false 6946000 6946 false false false 2 false false false false 0 0 false false false 3 false true false false 6946000 6946 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 10960000 10960 false false false xbrli:monetaryItemType monetary Carrying amounts due as of the balance sheet date from parties or arising from transactions not otherwise specified in the taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 8 -Article 5 false 1081 Notes Receivable from associated companies 2 us-gaap_NotesReceivableRelatedPartiesCurrent us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 240836000 240836 false false false xbrli:monetaryItemType monetary Amounts due from parties associated with the reporting entity as evidenced by a written promise to pay, due within 1 year (or 1 business cycle) Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph k -Subparagraph 1 -Article 4 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 57 -Paragraph 2 -Subparagraph d Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 3 -Subparagraph a -Article 5 false 1082 Materials and supplies, at average cost 2 us-gaap_InventoryNet us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 333709000 333709 false false false 2 false false false false 0 0 false false false 3 false true false false 333709000 333709 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 307079000 307079 false false false xbrli:monetaryItemType monetary Carrying amount (lower of cost or market) as of the balance sheet date of inventories less all valuation and other allowances. Excludes noncurrent inventory balances (expected to remain on hand past one year or one operating cycle, if longer). No authoritative reference available. false 1083 Prepayments and other 2 us-gaap_OtherAssetsCurrent us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 5600000 5600 false false false 2 false false false false 0 0 false false false 3 false true false false 5600000 5600 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 18356000 18356 false false false xbrli:monetaryItemType monetary Aggregate carrying amount, as of the balance sheet date, of current assets not separately presented elsewhere in the balance sheet. Current assets are expected to be realized or consumed within one year (or the normal operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 8 -Article 5 false 1084 Total current assets 2 us-gaap_AssetsCurrent us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 603525000 603525 false false false 2 false false false false 0 0 false false false 3 false true false false 603525000 603525 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 752964000 752964 false false false xbrli:monetaryItemType monetary Sum of the carrying amounts as of the balance sheet date of all assets that are expected to be realized in cash, sold, or consumed within one year (or the normal operating cycle, if longer). Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 9 -Article 5 true 1085 PROPERTY, PLANT AND EQUIPMENT: 2 us-gaap_PropertyPlantAndEquipmentNetAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 1086 In service 2 us-gaap_PropertyPlantAndEquipmentGross us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 5588112000 5588112 false false false 2 false false false false 0 0 false false false 3 false true false false 5588112000 5588112 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 5478346000 5478346 false false false xbrli:monetaryItemType monetary Carrying amount at the balance sheet date for long-lived physical assets used in the normal conduct of business and not intended for resale. This can include land, physical structures, machinery, vehicles, furniture, computer equipment, construction in progress, and similar items. Amount does not include depreciation. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 false 1087 Less - Accumulated provision for depreciation 2 us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 2824150000 2824150 false false false 2 false false false false 0 0 false false false 3 false true false false 2824150000 2824150 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 2778320000 2778320 false false false xbrli:monetaryItemType monetary The cumulative amount of depreciation, depletion and amortization (related to property, plant and equipment, but not including land) that has been recognized in the income statement. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 -Subparagraph c Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 14 -Article 5 true 1088 Total in service, net of accumulated depreciation 2 fe_NetPlantExcludingConstructionWorkInProgress fe false debit instant Net Plant Excluding Construction Work In Progress. false false false false false false false false false false false verboselabel false 1 false true false false 2763962000 2763962 false false false 2 false false false false 0 0 false false false 3 false true false false 2763962000 2763962 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 2700026000 2700026 false false false xbrli:monetaryItemType monetary Net Plant Excluding Construction Work In Progress. No authoritative reference available. false 1089 Construction work in progress 2 us-gaap_ConstructionInProgressGross us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 2149132000 2149132 false false false 2 false false false false 0 0 false false false 3 false true false false 2149132000 2149132 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 2049078000 2049078 false false false xbrli:monetaryItemType monetary Carrying amount at the balance sheet date of long-lived asset under construction that include construction costs to date on capital projects that have not been completed and assets being constructed that are not ready to be placed into service. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 true 1090 Total property, plant and equipment 2 us-gaap_PropertyPlantAndEquipmentNet us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 4913094000 4913094 false false false 2 false false false false 0 0 false false false 3 false true false false 4913094000 4913094 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 4749104000 4749104 false false false xbrli:monetaryItemType monetary Tangible assets that are held by an entity for use in the production or supply of goods and services, for rental to others, or for administrative purposes and that are expected to provide economic benefit for more than one year; net of accumulated depreciation. Examples include land, buildings, and production equipment. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 13 -Subparagraph a -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 12 -Paragraph 5 -Subparagraph b, c Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 8 -Article 7 true 1091 INVESTMENTS: 2 us-gaap_InvestmentsAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 1092 Nuclear plant decommissioning trusts 2 us-gaap_DecommissioningFundInvestments us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Decommission fund to pay for the costs of decontaminating and decommissioning of facilities through collection of revenues derived from utility assessments and government appropriations. Decommission fund investment for the process whereby a power station, at the end of its economic life, is taken permanently out of service and its site made available for other purposes. In the case of a nuclear station this comprises three different states of clearance. Immediately after the final closure, radioactive material such as nuclear fuel and operational waste is removed and the buildings surrounding the reactor shield are dismantled and finally the reactor itself is dismantled. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 12 -Article 5 false 1093 Investment in associated companies 2 fe_Investmentinassociatedcompanies fe false debit instant Investment in associated companies. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Investment in associated companies. No authoritative reference available. false 1094 Other 2 us-gaap_OtherLongTermInvestments us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 7003000 7003 false false false 2 false false false false 0 0 false false false 3 false true false false 7003000 7003 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 21127000 21127 false false false xbrli:monetaryItemType monetary Other noncurrent investments not otherwise specified in the taxonomy, not including investments in marketable securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 12 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 1 -Subparagraph f -Article 7 true 1095 Total investments 2 us-gaap_LongTermInvestments us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 7003000 7003 false false false 2 false false false false 0 0 false false false 3 false true false false 7003000 7003 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 21127000 21127 false false false xbrli:monetaryItemType monetary The total amount of investments that are intended to be held for an extended period of time (longer than one operating cycle). No authoritative reference available. true 1096 DEFERRED CHARGES AND OTHER ASSETS: 2 fe_DeferredChargesAndOtherAssetsAbstract fe false na duration Deferred Charges And Other Assets Abstract. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string Deferred Charges And Other Assets Abstract. false 1097 Accumulated deferred income taxes 2 us-gaap_DeferredTaxAssetsDeferredIncome us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 340072000 340072 false false false 2 false false false false 0 0 false false false 3 false true false false 340072000 340072 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 381849000 381849 false false false xbrli:monetaryItemType monetary The tax effect as of the balance sheet date of the amount of the estimated future tax deductions attributable to income recognized only for tax purposes and which will reverse when recognized under generally accepted accounting principles. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Paragraph 43 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Paragraph 11 -Subparagraph c false 1098 Goodwill 2 us-gaap_Goodwill us-gaap true debit instant No definition available. false false false false false false false false false false false false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Carrying amount as of the balance sheet date, which is the cumulative amount paid, adjusted for any amortization recognized prior to adoption of FAS 142 and for any impairment charges, in excess of the fair value of net assets acquired in one or more business combination transactions. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 142 -Paragraph 43 false 1099 Customer intangibles 2 us-gaap_FiniteLivedIntangibleAssetsNet us-gaap true debit instant No definition available. false false false false false false false false false false false false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary The aggregate sum of gross carrying value of a major finite-lived intangible asset class, less accumulated amortization and any impairment charges. A major class is composed of intangible assets that can be grouped together because they are similar, either by their nature or by their use in the operations of a company. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 142 -Paragraph 45 -Subparagraph a(1) false 1100 Property taxes 2 fe_PropertyTaxes fe false debit instant Property taxes. false false false false false false false false false false false verboselabel false 1 false true false false 27811000 27811 false false false 2 false false false false 0 0 false false false 3 false true false false 27811000 27811 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 27811000 27811 false false false xbrli:monetaryItemType monetary Property taxes. No authoritative reference available. false 1101 Unamortized sale and leaseback costs 2 fe_UnamortizedSaleAndLeasebackCosts fe false debit instant Unamortized sale and leaseback costs. false false false false false false false false false false false verboselabel false 1 false true false false 14168000 14168 false false false 2 false false false false 0 0 false false false 3 false true false false 14168000 14168 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 16454000 16454 false false false xbrli:monetaryItemType monetary Unamortized sale and leaseback costs. No authoritative reference available. false 1102 Other 2 us-gaap_OtherAssetsNoncurrent us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 76609000 76609 false false false 2 false false false false 0 0 false false false 3 false true false false 76609000 76609 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 71179000 71179 false false false xbrli:monetaryItemType monetary Aggregate carrying amount, as of the balance sheet date, of noncurrent assets not separately disclosed in the balance sheet due to materiality considerations. Noncurrent assets are expected to be realized or consumed after one year (or the normal operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 17 -Article 5 true 1103 Total deferred charges and other assets 2 us-gaap_AssetsNoncurrent us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 458660000 458660 false false false 2 false false false false 0 0 false false false 3 false true false false 458660000 458660 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 497293000 497293 false false false xbrli:monetaryItemType monetary Sum of the carrying amounts as of the balance sheet date of all assets that are expected to be realized in cash, sold or consumed after one year or beyond the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 18 -Article 5 true 1104 Total assets 2 us-gaap_Assets us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 5982282000 5982282 false false false 2 false false false false 0 0 false false false 3 false true false false 5982282000 5982282 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 6020488000 6020488 false false false xbrli:monetaryItemType monetary Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Concepts (CON) -Number 6 -Paragraph 25 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 18 -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 12 -Article 7 true 1105 CURRENT LIABILITIES: 2 us-gaap_LiabilitiesCurrentAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 1106 Currently payable long-term debt 2 us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 472357000 472357 false false false 2 false false false false 0 0 false false false 3 false true false false 472357000 472357 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 646402000 646402 false false false xbrli:monetaryItemType monetary Obligation related to long-term debt (excluding convertible debt) and capital leases, the portion which is due in one year or less in the future. No authoritative reference available. false 1107 Short-term borrowings- 2 us-gaap_ShortTermBorrowingsAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 1108 Associated companies 2 us-gaap_ShortTermNonBankLoansAndNotesPayable us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 85128000 85128 false false false 2 false false false false 0 0 false false false 3 false true false false 85128000 85128 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 9237000 9237 false false false xbrli:monetaryItemType monetary Carrying amount at the balance sheet date of borrowings from a creditor other than a bank, not elsewhere specified in the taxonomy, with a maturity within one year (or within one operating cycle if longer) from the date of borrowing. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19 -Subparagraph a -Article 5 false 1109 Other 2 us-gaap_ShortTermBorrowings us-gaap true credit instant No definition available. false false false false false false false false false false false terselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19 -Subparagraph a -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 13 -Subparagraph 2, 3 -Article 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 16 -Subparagraph a(1) -Article 7 false 1110 Accounts payable- 2 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 1111 Associated companies 2 us-gaap_AccountsPayableRelatedPartiesCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 257889000 257889 false false false 2 false false false false 0 0 false false false 3 false true false false 257889000 257889 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 170446000 170446 false false false xbrli:monetaryItemType monetary Amount for accounts payable to related parties. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19 -Subparagraph a -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 57 -Paragraph 2 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph k -Subparagraph 1 -Article 4 false 1112 Other 2 us-gaap_AccountsPayableCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false terselabel false 1 false true false false 134944000 134944 false false false 2 false false false false 0 0 false false false 3 false true false false 134944000 134944 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 193641000 193641 false false false xbrli:monetaryItemType monetary Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19 -Subparagraph a -Article 5 false 1113 Accrued taxes 2 us-gaap_AccruedIncomeTaxesCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 74125000 74125 false false false 2 false false false false 0 0 false false false 3 false true false false 74125000 74125 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 61055000 61055 false false false xbrli:monetaryItemType monetary Carrying amount as of the balance sheet date of the unpaid sum of the known and estimated amounts payable to satisfy all currently due domestic and foreign income tax obligations. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 15 -Subparagraph b(1) -Article 7 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 15 -Article 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20 -Article 5 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Interpretation (FIN) -Number 48 -Paragraph 15, 21 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Section Appendix E -Paragraph 289 false 1114 Other 2 us-gaap_OtherLiabilitiesCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 102780000 102780 false false false 2 false false false false 0 0 false false false 3 false true false false 102780000 102780 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 132314000 132314 false false false xbrli:monetaryItemType monetary Aggregate carrying amount, as of the balance sheet date, of current obligations not separately disclosed in the balance sheet due to materiality considerations. Current liabilities are expected to be paid within one year (or the normal operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 43 -Chapter 3 -Section A -Paragraph 8 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 6 -Paragraph 15 true 1115 Total current liabilities 2 us-gaap_LiabilitiesCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 1127223000 1127223 false false false 2 false false false false 0 0 false false false 3 false true false false 1127223000 1127223 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 1213095000 1213095 false false false xbrli:monetaryItemType monetary Total obligations incurred as part of normal operations that are expected to be paid during the following twelve months or within one business cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 21 -Article 5 true 1116 CAPITALIZATION: 2 us-gaap_CapitalizationLongtermDebtAndEquityAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 1117 Common stockholder's equity 2 us-gaap_StockholdersEquity us-gaap true credit instant No definition available. false false false false false false false false false false false terselabel false 1 false true false false 2504419000 2504419 false false false 2 false false false false 0 0 false false false 3 false true false false 2504419000 2504419 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 2346515000 2346515 false false false xbrli:monetaryItemType monetary Total of all Stockholders' Equity (deficit) items, net of receivables from officers, directors owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph A3 -Appendix A Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 4 -Section E Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29, 30, 31 -Article 5 false 1118 Long-term debt and other long-term obligations 2 us-gaap_LongTermDebtAndCapitalLeaseObligations us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 1820112000 1820112 false false false 2 false false false false 0 0 false false false 3 false true false false 1820112000 1820112 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 1906818000 1906818 false false false xbrli:monetaryItemType monetary Sum of the carrying values as of the balance sheet date of all long-term debt, which is debt initially having maturities due after one year from the balance sheet date or beyond the operating cycle, if longer, but excluding the portions thereof scheduled to be repaid within one year or the normal operating cycle, if longer plus capital lease obligations due to be paid more than one year after the balance sheet date. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 6 -Section H true 1119 Total capitalization 2 fe_TotalCapitalization fe false credit instant Total Capitalization. false false false false false false false false false false false totallabel false 1 false true false false 4324531000 4324531 false false false 2 false false false false 0 0 false false false 3 false true false false 4324531000 4324531 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 4253333000 4253333 false false false xbrli:monetaryItemType monetary Total Capitalization. No authoritative reference available. true 1120 NONCURRENT LIABILITIES: 2 us-gaap_LiabilitiesNoncurrentAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 1121 Deferred gain on sale and leaseback transaction 2 us-gaap_SaleLeasebackTransactionDeferredGainNet us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary The portion of the gain that will be recorded as income or a reduction in rent expense in future periods less amounts recognized in the current period. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 13 -Paragraph 33 false 1122 Accumulated deferred income taxes 2 us-gaap_DeferredTaxLiabilitiesNoncurrent us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Represents the noncurrent portion of deferred tax liabilities, which result from applying the applicable tax rate to net taxable temporary differences pertaining to each jurisdiction to which the entity is obligated to pay income tax. A noncurrent taxable temporary difference is a difference between the tax basis and the carrying amount of a noncurrent asset or liability in the financial statements prepared in accordance with generally accepted accounting principles. In a classified statement of financial position, an enterprise shall separate deferred tax liabilities and assets into a current amount and a noncurrent amount. Deferred tax liabilities and assets shall be classified as current or noncurrent based on the classification of the related asset or liability for financial reporting. A deferred tax liability or asset that is not related to an asset or liability for financial reporting, including deferred tax assets related to carryforwards, shall be classified according to the expected reversal date of the temporary difference. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Paragraph 41, 42 false 1123 Accumulated deferred investment tax credits 2 us-gaap_AccumulatedDeferredInvestmentTaxCredit us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 34820000 34820 false false false 2 false false false false 0 0 false false false 3 false true false false 34820000 34820 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 36359000 36359 false false false xbrli:monetaryItemType monetary The noncurrent portion of the reserve for accumulated deferred investment tax credits as of the balance sheet date. This is the remaining investment credit, which will reduce the cost of services collected from ratepayers by a ratable portion over the investment's regulatory life. No authoritative reference available. false 1124 Asset retirement obligations 2 us-gaap_AssetRetirementObligationsNoncurrent us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 26196000 26196 false false false 2 false false false false 0 0 false false false 3 false true false false 26196000 26196 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 25714000 25714 false false false xbrli:monetaryItemType monetary Noncurrent portion of the carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 143 -Paragraph 3, 10, 22 false 1125 Retirement benefits 2 us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansNoncurrentLiabilities us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 188023000 188023 false false false 2 false false false false 0 0 false false false 3 false true false false 188023000 188023 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 170891000 170891 false false false xbrli:monetaryItemType monetary For classified balance sheets this represents the noncurrent liability for underfunded plans recognized in the balance sheet that is associated with the defined benefit pension plans and other postretirement defined benefit plans. For unclassified balance sheets, this represents the entire liability recognized in the balance sheet that is associated with the defined benefit plans. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph c Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 6 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 3 false 1126 Property taxes 2 fe_PropertyTaxesNoncurrentLiabilities fe false credit instant Property taxes. false false false false false false false false false false false verboselabel false 1 false true false false 27811000 27811 false false false 2 false false false false 0 0 false false false 3 false true false false 27811000 27811 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 27811000 27811 false false false xbrli:monetaryItemType monetary Property taxes. No authoritative reference available. false 1127 Lease market valuation liability 2 us-gaap_OffMarketLeaseUnfavorable us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 239447000 239447 false false false 2 false false false false 0 0 false false false 3 false true false false 239447000 239447 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 262200000 262200 false false false xbrli:monetaryItemType monetary This element represents a liability associated with the acquisition of an off-market lease when the terms of the lease are unfavorable to the market terms for the lease at the date of acquisition. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141 -Paragraph 37 false 1128 Other 2 us-gaap_OtherLiabilitiesNoncurrent us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 14231000 14231 false false false 2 false false false false 0 0 false false false 3 false true false false 14231000 14231 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 31085000 31085 false false false xbrli:monetaryItemType monetary Aggregate carrying amount, as of the balance sheet date, of noncurrent obligations not separately disclosed in the balance sheet due to materiality considerations. Noncurrent liabilities are expected to be paid after one year (or the normal operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 24 -Article 5 true 1129 Total noncurrent liabilities 2 us-gaap_LiabilitiesNoncurrent us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 530528000 530528 false false false 2 false false false false 0 0 false false false 3 false true false false 530528000 530528 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 554060000 554060 false false false xbrli:monetaryItemType monetary Total obligations incurred as part of normal operations that is expected to be repaid beyond the following twelve months or one business cycle. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22, 23, 24, 25, 26, 27 -Article 5 true 1130 Total liabilities and capitalization 2 us-gaap_LiabilitiesAndStockholdersEquity us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 5982282000 5982282 false false false 2 false false false false 0 0 false false false 3 false true false false 5982282000 5982282 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 6020488000 6020488 false false false xbrli:monetaryItemType monetary Total of all Liabilities and Stockholders' Equity items. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 32 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 25 -Article 7 true 1131 Statements of Cash Flows [Abstract] 2 us-gaap_StatementOfCashFlowsAbstract us-gaap true na duration No definition available. false false false false false true false false false false false false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 1132 NET CASH PROVIDED FROM (USED FOR) OPERATING ACTIVITIES 2 us-gaap_NetCashProvidedByUsedInOperatingActivities us-gaap true na duration No definition available. false false false false false false false false false false false terselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 163325000 163325 false false false 4 false true false false 314041000 314041 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net cash from (used in) all of the entity's operating activities, including those of discontinued operations, of the reporting entity. Operating activities generally involve producing and delivering goods and providing services. Operating activity cash flows include transactions, adjustments, and changes in value that are not defined as investing or financing activities. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 26 false 1133 New Financing- 2 fe_NewFinancingAbstract fe false na duration New Financing Abstract. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string New Financing Abstract. false 1134 Long-term debt 2 us-gaap_ProceedsFromIssuanceOfLongTermDebt us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false true false false 347710000 347710 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 19 -Subparagraph b false 1135 Short-term borrowings, net 2 us-gaap_ProceedsFromShortTermDebt us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 75891000 75891 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash inflow from a borrowing having initial term of repayment within one year or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 19 -Subparagraph b false 1136 Redemptions and Repayments- 2 fe_RedemptionsAndRepaymentsAbstract fe false na duration Redemptions And Repayments Abstract. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string Redemptions And Repayments Abstract. false 1137 Long-term debt 2 us-gaap_RepaymentsOfLongTermDebt us-gaap true credit duration No definition available. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -260865000 -260865 false false false 4 false true false false -260372000 -260372 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 20 -Subparagraph b false 1138 Short-term borrowings, net 2 us-gaap_RepaymentsOfShortTermDebt us-gaap true credit duration No definition available. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false -82587000 -82587 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash outflow for a borrowing having initial term of repayment within one year or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 20 -Subparagraph b false 1139 Other 2 us-gaap_ProceedsFromPaymentsForOtherFinancingActivities us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -128000 -128 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net cash inflow (outflow) from other financing activities. This element is used when there is not a more specific and appropriate element in the taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18, 19, 20 true 1140 Net cash used for financing activities 2 us-gaap_NetCashProvidedByUsedInFinancingActivities us-gaap true debit duration No definition available. false false false false false false false false false false false terselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -185102000 -185102 false false false 4 false true false false 4751000 4751 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net cash inflow (outflow) from financing activity for the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 26 false 1141 CASH FLOWS FROM INVESTING ACTIVITIES: 2 us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 1142 Property additions 2 us-gaap_PaymentsToAcquireProductiveAssets us-gaap true credit duration No definition available. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -333063000 -333063 false false false 4 false true false false -332789000 -332789 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash outflow for purchases of and capital improvements on property, plant and equipment (capital expenditures), software, and other intangible assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 17 -Subparagraph c false 1143 Proceeds from asset sales 2 us-gaap_ProceedsFromSaleOfOtherProductiveAssets us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 115657000 115657 false false false 4 false true false false 15771000 15771 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash inflow from the sale of other tangible or intangible assets used to produce goods or deliver services not otherwise defined in the taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 16 -Subparagraph c false 1144 Sales of investment securities held in trusts 2 us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash inflow associated with the sale of debt and equity securities classified as available-for-sale securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 16 -Subparagraph a Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 18 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 16 -Subparagraph b false 1145 Purchases of investment securities held in trusts 2 us-gaap_PaymentsToAcquireAvailableForSaleSecurities us-gaap true credit duration No definition available. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash outflow to acquire debt and equity securities not classified as either held-to-maturity securities or trading securities which would be classified as available-for-sale securities and reported at fair value, with unrealized gains and losses excluded from earnings and reported in a separate component of shareholders' equity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 17 -Subparagraph b Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 18 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 17 -Subparagraph a false 1146 Loans from associated companies, net 2 us-gaap_ProceedsFromPaymentsForLongTermLoansForRelatedParties us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 240836000 240836 false false false 4 false true false false 20669000 20669 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash inflow or outflow associated with long-term loans for related parties where one party can exercise control or significant influence over another party, including affiliates, owners or officers and their immediate families, pension trusts, and so forth. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15, 16, 17 false 1147 Customer acquisition costs 2 us-gaap_PaymentsToAcquireIntangibleAssets us-gaap true credit duration No definition available. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash outflow to acquire asset without physical form usually arising from contractual or other legal rights, excluding goodwill. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 17 -Subparagraph c false 1148 Leasehold improvement payments to associated companies 2 fe_LeaseholdImprovementPaymentsToAssociatedCompanies fe false credit duration Leasehold improvement payments to associated companies. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Leasehold improvement payments to associated companies. No authoritative reference available. false 1149 Other 2 us-gaap_PaymentsForProceedsFromOtherInvestingActivities us-gaap true credit duration No definition available. false false false false false false false false false false true negatedtotal false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -1654000 -1654 false false false 4 false true false false -22448000 -22448 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net cash outflow (inflow) from other investing activities. This element is used when there is not a more specific and appropriate element in the taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 true 1150 Net cash used for investing activities 2 us-gaap_NetCashProvidedByUsedInInvestingActivities us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 21776000 21776 false false false 4 false true false false -318797000 -318797 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net cash inflow (outflow) from investing activity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 26 true 1151 Net change in cash and cash equivalents 2 us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease us-gaap true na duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -1000 -1 false false false 4 false true false false -5000 -5 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net change between the beginning and ending balance of cash and cash equivalents. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 26 false 1152 Cash and cash equivalents at beginning of period 2 us-gaap_CashAndCashEquivalentsAtCarryingValue us-gaap true debit instant No definition available. false false false false false false false false true false false periodstartlabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 3000 3 false false false 4 false true false false 39000 39 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits should not be reported as cash and cash equivalents. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7, 26 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 8, 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7 -Footnote 1 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 false 1153 Cash and cash equivalents at end of period 2 us-gaap_CashAndCashEquivalentsAtCarryingValue us-gaap true debit instant No definition available. false false false false false false false false false true false periodendlabel false 1 false true false false 2000 2 false false false 2 false true false false 34000 34 false false false 3 false true false false 2000 2 false false false 4 false true false false 34000 34 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits should not be reported as cash and cash equivalents. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7, 26 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 8, 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7 -Footnote 1 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 false 1156 FGCO [ Member] | Affiliates Member 0 na true na na No definition available. false true false false false false false false false false false http://firstenergycorp.com/role/disclosuresupplementalguarantorinformationdetails false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false false 51 USD true false false false FGCO [ Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_NonGuarantorSubsidiariesMember dei_LegalEntityAxis explicitMember false false Affiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_AffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 52 USD true false false false FGCO [ Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_NonGuarantorSubsidiariesMember dei_LegalEntityAxis explicitMember false false Affiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_AffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 53 USD true false false false FGCO [ Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_NonGuarantorSubsidiariesMember dei_LegalEntityAxis explicitMember false false Affiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_AffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 54 USD true false false false FGCO [ Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_NonGuarantorSubsidiariesMember dei_LegalEntityAxis explicitMember false false Affiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_AffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ na No definition available. No authoritative reference available. false 1159 EXPENSES: 2 us-gaap_CostsAndExpensesAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 1161 Purchased power 2 us-gaap_CostOfPurchasedPower us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 7163000 7163 false false false 2 false true false false 5018000 5018 false false false 3 false true false false 12242000 12242 false false false 4 false true false false 7100000 7100 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Cost of electricity purchased and sold during the reporting period. No authoritative reference available. false 1261 FGCO [ Member] | Nonaffiliates Member 0 na true na na No definition available. false true false false false false false false false false false http://firstenergycorp.com/role/disclosuresupplementalguarantorinformationdetails false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false false 55 USD true false false false FGCO [ Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_NonGuarantorSubsidiariesMember dei_LegalEntityAxis explicitMember false false Nonaffiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_NonaffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 56 USD true false false false FGCO [ Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_NonGuarantorSubsidiariesMember dei_LegalEntityAxis explicitMember false false Nonaffiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_NonaffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 57 USD true false false false FGCO [ Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_NonGuarantorSubsidiariesMember dei_LegalEntityAxis explicitMember false false Nonaffiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_NonaffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 58 USD true false false false FGCO [ Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_NonGuarantorSubsidiariesMember dei_LegalEntityAxis explicitMember false false Nonaffiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_NonaffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ na No definition available. No authoritative reference available. false 1264 EXPENSES: 2 us-gaap_CostsAndExpensesAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 1266 Purchased power 2 us-gaap_CostOfPurchasedPower us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false true false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Cost of electricity purchased and sold during the reporting period. No authoritative reference available. false 1366 Affiliates Member | FES [Member] 0 na true na na No definition available. false true false false false false false false false false false http://firstenergycorp.com/role/disclosuresupplementalguarantorinformationdetails false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false false 59 USD true false false false Affiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_AffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember false false FES [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_SubsidiaryEightMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 60 USD true false false false Affiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_AffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember false false FES [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_SubsidiaryEightMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 61 USD true false false false Affiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_AffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember false false FES [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_SubsidiaryEightMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 62 USD true false false false Affiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_AffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember false false FES [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_SubsidiaryEightMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ na No definition available. No authoritative reference available. false 1369 EXPENSES: 2 us-gaap_CostsAndExpensesAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 1371 Purchased power 2 us-gaap_CostOfPurchasedPower us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 912858000 912858 false false false 2 false true false false 814622000 814622 false false false 3 false true false false 1881395000 1881395 false false false 4 false true false false 1729883000 1729883 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Cost of electricity purchased and sold during the reporting period. No authoritative reference available. false 1471 Nonaffiliates Member | FES [Member] 0 na true na na No definition available. false true false false false false false false false false false http://firstenergycorp.com/role/disclosuresupplementalguarantorinformationdetails false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false false 63 USD true false false false Nonaffiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_NonaffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember false false FES [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_SubsidiaryEightMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 64 USD true false false false Nonaffiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_NonaffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember false false FES [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_SubsidiaryEightMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 65 USD true false false false Nonaffiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_NonaffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember false false FES [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_SubsidiaryEightMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 66 USD true false false false Nonaffiliates Member us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis xbrldi http://xbrl.org/2006/xbrldi fe_NonaffiliatesMember us-gaap_InvestmentsInAndAdvancesToAffiliatesCategorizationAxis explicitMember false false FES [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_SubsidiaryEightMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ na No definition available. No authoritative reference available. false 1474 EXPENSES: 2 us-gaap_CostsAndExpensesAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 1476 Purchased power 2 us-gaap_CostOfPurchasedPower us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 298820000 298820 false false false 2 false true false false 185613000 185613 false false false 3 false true false false 749035000 749035 false false false 4 false true false false 345955000 345955 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Cost of electricity purchased and sold during the reporting period. No authoritative reference available. false 1576 Parent Company [Member] 0 na true na na No definition available. false true false false false false false false false false false http://firstenergycorp.com/role/disclosuresupplementalguarantorinformationdetails false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false false 67 USD true false false false Parent Company [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_ParentCompanyMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 68 USD true false false false Parent Company [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi us-gaap_ParentCompanyMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ na No definition available. No authoritative reference available. false 1589 OTHER INCOME (EXPENSE): 2 fe_OtherIncomeExpenseAbstract fe false na duration Other Income Expense Abstract. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string Other Income Expense Abstract. false 1590 Investment income 2 us-gaap_InvestmentIncomeInterestAndDividend us-gaap true credit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 37000000 37000 false false false 4 false true false false 30000000 30000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Income derived from investments in debt and equity securities and on cash and cash equivalents. Interest income represents earnings which reflect the time value of money or transactions in which the payments are for the use or forbearance of money. Dividend income represents a distribution of earnings to shareholders by investee companies. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 14 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 7 -Subparagraph a, b -Article 5 false 1681 FES [Member] 0 na true na na No definition available. false true false false false false false false false false false http://firstenergycorp.com/role/disclosuresupplementalguarantorinformationdetails false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false false 69 USD true false false false FES [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_SubsidiaryEightMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 70 USD true false false false FES [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_SubsidiaryEightMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 71 USD true false false false FES [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_SubsidiaryEightMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 72 USD true false false false FES [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_SubsidiaryEightMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 73 USD true false false false FES [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_SubsidiaryEightMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ na No definition available. No authoritative reference available. false 1682 Condensed Consolidated Statements of Income (Unaudited) 2 us-gaap_IncomeStatementAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 1683 Total revenues 2 us-gaap_ElectricUtilityRevenue us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 1295700000 1295700 false false false 2 false true false false 1067987000 1067987 false false false 3 false true false false 2662725000 2662725 false false false 4 false true false false 2269882000 2269882 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The aggregate revenue, whether regulated or unregulated, derived from the generation, transmission and distribution of electricity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 1 -Article 5 true 1684 EXPENSES: 2 us-gaap_CostsAndExpensesAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 1685 Fuel 2 us-gaap_FuelCosts us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 7268000 7268 false false false 2 false true false false 5027000 5027 false false false 3 false true false false 12365000 12365 false false false 4 false true false false 7122000 7122 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Fuel costs incurred that are directly related to goods produced and sold and services rendered during the reporting period. No authoritative reference available. false 1687 Other operating expenses 2 us-gaap_OtherCostAndExpenseOperating us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 80983000 80983 false false false 2 false true false false 35771000 35771 false false false 3 false true false false 134109000 134109 false false false 4 false true false false 74038000 74038 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The total amount of other operating cost and expense items that are associated with the entity's normal revenue producing operation. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 3 -Article 5 false 1688 Provision for depreciation 2 us-gaap_DepreciationNonproduction us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 711000 711 false false false 2 false true false false 1017000 1017 false false false 3 false true false false 1501000 1501 false false false 4 false true false false 2036000 2036 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The expense recognized in the current period that allocates the cost of nonproduction tangible assets over their useful lives. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 false 1691 General taxes 2 us-gaap_TaxesExcludingIncomeAndExciseTaxes us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 5718000 5718 false false false 2 false true false false 3769000 3769 false false false 3 false true false false 11216000 11216 false false false 4 false true false false 8475000 8475 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary All taxes not related to income of the entity or excise or sales taxes levied on the revenue of the entity that are not reported elsewhere. These taxes could include production, real estate, personal property, and pump tax. No authoritative reference available. true 1692 Total expenses 2 us-gaap_CostsAndExpenses us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 1306358000 1306358 false false false 2 false true false false 1045819000 1045819 false false false 3 false true false false 2789621000 2789621 false false false 4 false true false false 2167509000 2167509 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Total costs of sales and operating expenses for the period. No authoritative reference available. true 1693 OPERATING INCOME 2 us-gaap_OperatingIncomeLoss us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false -10658000 -10658 false false false 2 false true false false 22168000 22168 false false false 3 false true false false -126896000 -126896 false false false 4 false true false false 102373000 102373 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net result for the period of deducting operating expenses from operating revenues. No authoritative reference available. true 1694 OTHER INCOME (EXPENSE): 2 fe_OtherIncomeExpenseAbstract fe false na duration Other Income Expense Abstract. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string Other Income Expense Abstract. false 1695 Investment income 2 us-gaap_InvestmentIncomeInterestAndDividend us-gaap true credit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 1811000 1811 false false false 2 false true false false -518000 -518 false false false 3 false true false false 3708000 3708 false false false 4 false true false false 214000 214 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Income derived from investments in debt and equity securities and on cash and cash equivalents. Interest income represents earnings which reflect the time value of money or transactions in which the payments are for the use or forbearance of money. Dividend income represents a distribution of earnings to shareholders by investee companies. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 14 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 7 -Subparagraph a, b -Article 5 false 1696 Miscellaneous income (expense), including 2 fe_Miscellaneousincomeexpenseabstract fe false na duration Miscellaneous income expense Abstact. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string Miscellaneous income expense Abstact. false 1697 net income from equity investees 2 us-gaap_SegmentReportingInformationEquityInNetIncomeOfEquityMethodInvesteesOfSegment us-gaap true credit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 151291000 151291 false false false 2 false true false false 289312000 289312 false false false 3 false true false false 317664000 317664 false false false 4 false true false false 409093000 409093 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Amount of income or loss recognized by the reportable segment for its share of an investee's net income or loss reported under the equity method of accounting. Must be disclosed if the amount (a) is included in the measure of segment profit or loss reviewed by the chief operating decision maker or (b) is otherwise regularly provided to the chief operating decision maker, even if not included in that measure of segment profit or loss Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 131 -Paragraph 27 -Subparagraph g false 1698 Interest expense to affiliates 2 fe_Interestanddebtexpenseaffiliates fe false debit duration Interest expense to affiliates false false false false false false false false false false true negated false 1 false true false false -61000 -61 false false false 2 false true false false -34000 -34 false false false 3 false true false false -119000 -119 false false false 4 false true false false -68000 -68 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Interest expense to affiliates No authoritative reference available. false 1699 Interest expense 2 us-gaap_InterestAndDebtExpense us-gaap true debit duration No definition available. false false false false false false false false false false true negated false 1 false true false false -24262000 -24262 false false false 2 false true false false -2900000 -2900 false false false 3 false true false false -47635000 -47635 false false false 4 false true false false -5420000 -5420 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Interest and debt related expenses associated with nonoperating financing activities of the entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 34 -Paragraph 21 false 1700 Capitalized interest 2 us-gaap_PublicUtilitiesAllowanceForFundsUsedDuringConstructionAdditions us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 98000 98 false false false 2 false true false false 46000 46 false false false 3 false true false false 198000 198 false false false 4 false true false false 97000 97 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Total increase in earnings in the period representing the cost of equity (rate of return) and borrowed funds (interest rate) used to finance construction of regulated assets, which is expected to be recovered through rate adjustments. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 71 -Paragraph 15 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 90 -Paragraph 8 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 92 -Paragraph 8, 9, 12 true 1701 Total other expense 2 us-gaap_NonoperatingIncomeExpense us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 128877000 128877 false false false 2 false true false false 285906000 285906 false false false 3 false true false false 273816000 273816 false false false 4 false true false false 403916000 403916 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The aggregate amount of income (expense) from ancillary business-related activities (that is to say, excluding major activities considered part of the normal operations of the business). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 7 -Article 5 true 1702 INCOME BEFORE INCOME TAXES 2 us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments us-gaap true credit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 118219000 118219 false false false 2 false true false false 308074000 308074 false false false 3 false true false false 146920000 146920 false false false 4 false true false false 506289000 506289 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Sum of operating profit and nonoperating income (expense) before income (loss) from equity method investments, income taxes, extraordinary items, cumulative effects of changes in accounting principles, and noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph h -Subparagraph 1(i) -Article 4 false 1703 INCOME TAXES 2 us-gaap_IncomeTaxExpenseBenefit us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false -15706000 -15706 false false false 2 false true false false 10672000 10672 false false false 3 false true false false -66931000 -66931 false false false 4 false true false false 38206000 38206 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The sum of the current income tax expense (benefit) and the deferred income tax expense (benefit) pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph h -Article 4 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Paragraph 45 -Subparagraph a, b true 1704 NET INCOME 2 us-gaap_ProfitLoss us-gaap true credit duration No definition available. false false false false false false false false false false false terselabel false 1 false true false false 133925000 133925 false false false 2 false true false false 297402000 297402 false false false 3 false true false false 213851000 213851 false false false 4 false true false false 468083000 468083 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph A1, A4, A5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 5 -Subparagraph b Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 29 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph a Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph c(1) false 1705 CURRENT ASSETS: 2 us-gaap_AssetsCurrentAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 1706 Cash and cash equivalents 2 us-gaap_CashAndCashEquivalentsAtCarryingValue us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false true false false 120000000 120000 false false false 3 false true false false 0 0 false false false 4 false true false false 120000000 120000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits should not be reported as cash and cash equivalents. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7, 26 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 8, 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7 -Footnote 1 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 false 1707 Receivables 2 us-gaap_ReceivablesNetCurrentAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 1708 Customers 2 us-gaap_AccountsReceivableNetCurrent us-gaap true debit instant No definition available. false false false false false false false false false false false terselabel false 1 false true false false 315178000 315178 false false false 2 false false false false 0 0 false false false 3 false true false false 315178000 315178 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 195107000 195107 false false false xbrli:monetaryItemType monetary Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 3 -Subparagraph a(1) -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 4 -Article 5 false 1709 Associated companies 2 us-gaap_AccountsReceivableRelatedPartiesCurrent us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 327070000 327070 false false false 2 false false false false 0 0 false false false 3 false true false false 327070000 327070 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 305298000 305298 false false false xbrli:monetaryItemType monetary Amount of receivables arising from transactions with related parties due within one year or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph k -Subparagraph 1 -Article 4 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 57 -Paragraph 2 -Subparagraph d Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 3 -Subparagraph a -Article 5 false 1710 Other 2 us-gaap_OtherReceivables us-gaap true debit instant No definition available. false false false false false false false false false false false terselabel false 1 false true false false 24815000 24815 false false false 2 false false false false 0 0 false false false 3 false true false false 24815000 24815 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 28394000 28394 false false false xbrli:monetaryItemType monetary Carrying amounts due as of the balance sheet date from parties or arising from transactions not otherwise specified in the taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 8 -Article 5 false 1711 Notes Receivable from associated companies 2 us-gaap_NotesReceivableRelatedPartiesCurrent us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 84337000 84337 false false false 2 false false false false 0 0 false false false 3 false true false false 84337000 84337 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 416404000 416404 false false false xbrli:monetaryItemType monetary Amounts due from parties associated with the reporting entity as evidenced by a written promise to pay, due within 1 year (or 1 business cycle) Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph k -Subparagraph 1 -Article 4 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 57 -Paragraph 2 -Subparagraph d Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 3 -Subparagraph a -Article 5 false 1712 Materials and supplies, at average cost 2 us-gaap_InventoryNet us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 23804000 23804 false false false 2 false false false false 0 0 false false false 3 false true false false 23804000 23804 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 17265000 17265 false false false xbrli:monetaryItemType monetary Carrying amount (lower of cost or market) as of the balance sheet date of inventories less all valuation and other allowances. Excludes noncurrent inventory balances (expected to remain on hand past one year or one operating cycle, if longer). No authoritative reference available. false 1713 Prepayments and other 2 us-gaap_OtherAssetsCurrent us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 162845000 162845 false false false 2 false false false false 0 0 false false false 3 false true false false 162845000 162845 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 80025000 80025 false false false xbrli:monetaryItemType monetary Aggregate carrying amount, as of the balance sheet date, of current assets not separately presented elsewhere in the balance sheet. Current assets are expected to be realized or consumed within one year (or the normal operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 8 -Article 5 false 1714 Total current assets 2 us-gaap_AssetsCurrent us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 938049000 938049 false false false 2 false false false false 0 0 false false false 3 false true false false 938049000 938049 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 1042493000 1042493 false false false xbrli:monetaryItemType monetary Sum of the carrying amounts as of the balance sheet date of all assets that are expected to be realized in cash, sold, or consumed within one year (or the normal operating cycle, if longer). Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 9 -Article 5 true 1715 PROPERTY, PLANT AND EQUIPMENT: 2 us-gaap_PropertyPlantAndEquipmentNetAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 1716 In service 2 us-gaap_PropertyPlantAndEquipmentGross us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 93403000 93403 false false false 2 false false false false 0 0 false false false 3 false true false false 93403000 93403 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 90474000 90474 false false false xbrli:monetaryItemType monetary Carrying amount at the balance sheet date for long-lived physical assets used in the normal conduct of business and not intended for resale. This can include land, physical structures, machinery, vehicles, furniture, computer equipment, construction in progress, and similar items. Amount does not include depreciation. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 false 1717 Less - Accumulated provision for depreciation 2 us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 15742000 15742 false false false 2 false false false false 0 0 false false false 3 false true false false 15742000 15742 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 13649000 13649 false false false xbrli:monetaryItemType monetary The cumulative amount of depreciation, depletion and amortization (related to property, plant and equipment, but not including land) that has been recognized in the income statement. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 -Subparagraph c Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 14 -Article 5 true 1718 Total in service, net of accumulated depreciation 2 fe_NetPlantExcludingConstructionWorkInProgress fe false debit instant Net Plant Excluding Construction Work In Progress. false false false false false false false false false false false verboselabel false 1 false true false false 77661000 77661 false false false 2 false false false false 0 0 false false false 3 false true false false 77661000 77661 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 76825000 76825 false false false xbrli:monetaryItemType monetary Net Plant Excluding Construction Work In Progress. No authoritative reference available. false 1719 Construction work in progress 2 us-gaap_ConstructionInProgressGross us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 7412000 7412 false false false 2 false false false false 0 0 false false false 3 false true false false 7412000 7412 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 6032000 6032 false false false xbrli:monetaryItemType monetary Carrying amount at the balance sheet date of long-lived asset under construction that include construction costs to date on capital projects that have not been completed and assets being constructed that are not ready to be placed into service. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Principles Board Opinion (APB) -Number 12 -Paragraph 5 true 1720 Total property, plant and equipment 2 us-gaap_PropertyPlantAndEquipmentNet us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 85073000 85073 false false false 2 false false false false 0 0 false false false 3 false true false false 85073000 85073 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 82857000 82857 false false false xbrli:monetaryItemType monetary Tangible assets that are held by an entity for use in the production or supply of goods and services, for rental to others, or for administrative purposes and that are expected to provide economic benefit for more than one year; net of accumulated depreciation. Examples include land, buildings, and production equipment. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 13 -Subparagraph a -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 12 -Paragraph 5 -Subparagraph b, c Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 8 -Article 7 true 1721 INVESTMENTS: 2 us-gaap_InvestmentsAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 1722 Nuclear plant decommissioning trusts 2 us-gaap_DecommissioningFundInvestments us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Decommission fund to pay for the costs of decontaminating and decommissioning of facilities through collection of revenues derived from utility assessments and government appropriations. Decommission fund investment for the process whereby a power station, at the end of its economic life, is taken permanently out of service and its site made available for other purposes. In the case of a nuclear station this comprises three different states of clearance. Immediately after the final closure, radioactive material such as nuclear fuel and operational waste is removed and the buildings surrounding the reactor shield are dismantled and finally the reactor itself is dismantled. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 12 -Article 5 false 1723 Investment in associated companies 2 fe_Investmentinassociatedcompanies fe false debit instant Investment in associated companies. false false false false false false false false false false false verboselabel false 1 false true false false 4790066000 4790066 false false false 2 false false false false 0 0 false false false 3 false true false false 4790066000 4790066 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 4477602000 4477602 false false false xbrli:monetaryItemType monetary Investment in associated companies. No authoritative reference available. false 1724 Other 2 us-gaap_OtherLongTermInvestments us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 759000 759 false false false 2 false false false false 0 0 false false false 3 false true false false 759000 759 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 1137000 1137 false false false xbrli:monetaryItemType monetary Other noncurrent investments not otherwise specified in the taxonomy, not including investments in marketable securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 12 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 1 -Subparagraph f -Article 7 true 1725 Total investments 2 us-gaap_LongTermInvestments us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 4790825000 4790825 false false false 2 false false false false 0 0 false false false 3 false true false false 4790825000 4790825 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 4478739000 4478739 false false false xbrli:monetaryItemType monetary The total amount of investments that are intended to be held for an extended period of time (longer than one operating cycle). No authoritative reference available. true 1726 DEFERRED CHARGES AND OTHER ASSETS: 2 fe_DeferredChargesAndOtherAssetsAbstract fe false na duration Deferred Charges And Other Assets Abstract. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string Deferred Charges And Other Assets Abstract. false 1727 Accumulated deferred income taxes 2 us-gaap_DeferredTaxAssetsDeferredIncome us-gaap true debit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 78986000 78986 false false false 2 false false false false 0 0 false false false 3 false true false false 78986000 78986 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 93379000 93379 false false false xbrli:monetaryItemType monetary The tax effect as of the balance sheet date of the amount of the estimated future tax deductions attributable to income recognized only for tax purposes and which will reverse when recognized under generally accepted accounting principles. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Paragraph 43 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Paragraph 11 -Subparagraph c false 1728 Goodwill 2 us-gaap_Goodwill us-gaap true debit instant No definition available. false false false false false false false false false false false false 1 false true false false 24248000 24248 false false false 2 false false false false 0 0 false false false 3 false true false false 24248000 24248 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 24248000 24248 false false false xbrli:monetaryItemType monetary Carrying amount as of the balance sheet date, which is the cumulative amount paid, adjusted for any amortization recognized prior to adoption of FAS 142 and for any impairment charges, in excess of the fair value of net assets acquired in one or more business combination transactions. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 142 -Paragraph 43 false 1729 Customer intangibles 2 us-gaap_FiniteLivedIntangibleAssetsNet us-gaap true debit instant No definition available. false false false false false false false false false false false false 1 false true false false 118219000 118219 false false false 2 false false false false 0 0 false false false 3 false true false false 118219000 118219 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 16566000 16566 false false false xbrli:monetaryItemType monetary The aggregate sum of gross carrying value of a major finite-lived intangible asset class, less accumulated amortization and any impairment charges. A major class is composed of intangible assets that can be grouped together because they are similar, either by their nature or by their use in the operations of a company. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 142 -Paragraph 45 -Subparagraph a(1) false 1730 Property taxes 2 fe_PropertyTaxes fe false debit instant Property taxes. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Property taxes. No authoritative reference available. false 1731 Unamortized sale and leaseback costs 2 fe_UnamortizedSaleAndLeasebackCosts fe false debit instant Unamortized sale and leaseback costs. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Unamortized sale and leaseback costs. No authoritative reference available. false 1732 Other 2 us-gaap_OtherAssetsNoncurrent us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 102829000 102829 false false false 2 false false false false 0 0 false false false 3 false true false false 102829000 102829 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 82845000 82845 false false false xbrli:monetaryItemType monetary Aggregate carrying amount, as of the balance sheet date, of noncurrent assets not separately disclosed in the balance sheet due to materiality considerations. Noncurrent assets are expected to be realized or consumed after one year (or the normal operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 17 -Article 5 true 1733 Total deferred charges and other assets 2 us-gaap_AssetsNoncurrent us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 324282000 324282 false false false 2 false false false false 0 0 false false false 3 false true false false 324282000 324282 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 217038000 217038 false false false xbrli:monetaryItemType monetary Sum of the carrying amounts as of the balance sheet date of all assets that are expected to be realized in cash, sold or consumed after one year or beyond the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 18 -Article 5 true 1734 Total assets 2 us-gaap_Assets us-gaap true debit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 6138229000 6138229 false false false 2 false false false false 0 0 false false false 3 false true false false 6138229000 6138229 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 5821127000 5821127 false false false xbrli:monetaryItemType monetary Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Concepts (CON) -Number 6 -Paragraph 25 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 18 -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 12 -Article 7 true 1735 CURRENT LIABILITIES: 2 us-gaap_LiabilitiesCurrentAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 1736 Currently payable long-term debt 2 us-gaap_LongTermDebtAndCapitalLeaseObligationsCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 755000 755 false false false 2 false false false false 0 0 false false false 3 false true false false 755000 755 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 736000 736 false false false xbrli:monetaryItemType monetary Obligation related to long-term debt (excluding convertible debt) and capital leases, the portion which is due in one year or less in the future. No authoritative reference available. false 1737 Short-term borrowings- 2 us-gaap_ShortTermBorrowingsAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 1738 Associated companies 2 us-gaap_ShortTermNonBankLoansAndNotesPayable us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Carrying amount at the balance sheet date of borrowings from a creditor other than a bank, not elsewhere specified in the taxonomy, with a maturity within one year (or within one operating cycle if longer) from the date of borrowing. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19 -Subparagraph a -Article 5 false 1739 Other 2 us-gaap_ShortTermBorrowings us-gaap true credit instant No definition available. false false false false false false false false false false false terselabel false 1 false true false false 100000000 100000 false false false 2 false false false false 0 0 false false false 3 false true false false 100000000 100000 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 100000000 100000 false false false xbrli:monetaryItemType monetary Reflects the total carrying amount as of the balance sheet date of debt having initial terms less than one year or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19 -Subparagraph a -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 13 -Subparagraph 2, 3 -Article 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 16 -Subparagraph a(1) -Article 7 false 1740 Accounts payable- 2 us-gaap_AccountsPayableAndAccruedLiabilitiesCurrentAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 1741 Associated companies 2 us-gaap_AccountsPayableRelatedPartiesCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 311959000 311959 false false false 2 false false false false 0 0 false false false 3 false true false false 311959000 311959 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 261788000 261788 false false false xbrli:monetaryItemType monetary Amount for accounts payable to related parties. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19 -Subparagraph a -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 57 -Paragraph 2 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph k -Subparagraph 1 -Article 4 false 1742 Other 2 us-gaap_AccountsPayableCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false terselabel false 1 false true false false 101776000 101776 false false false 2 false false false false 0 0 false false false 3 false true false false 101776000 101776 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 51722000 51722 false false false xbrli:monetaryItemType monetary Carrying value as of the balance sheet date of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19 -Subparagraph a -Article 5 false 1743 Accrued taxes 2 us-gaap_AccruedIncomeTaxesCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 1717000 1717 false false false 2 false false false false 0 0 false false false 3 false true false false 1717000 1717 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 44213000 44213 false false false xbrli:monetaryItemType monetary Carrying amount as of the balance sheet date of the unpaid sum of the known and estimated amounts payable to satisfy all currently due domestic and foreign income tax obligations. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 15 -Subparagraph b(1) -Article 7 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 15 -Article 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20 -Article 5 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Interpretation (FIN) -Number 48 -Paragraph 15, 21 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Section Appendix E -Paragraph 289 false 1744 Other 2 us-gaap_OtherLiabilitiesCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 216207000 216207 false false false 2 false false false false 0 0 false false false 3 false true false false 216207000 216207 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 173015000 173015 false false false xbrli:monetaryItemType monetary Aggregate carrying amount, as of the balance sheet date, of current obligations not separately disclosed in the balance sheet due to materiality considerations. Current liabilities are expected to be paid within one year (or the normal operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 20 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 43 -Chapter 3 -Section A -Paragraph 8 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 6 -Paragraph 15 true 1745 Total current liabilities 2 us-gaap_LiabilitiesCurrent us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 732414000 732414 false false false 2 false false false false 0 0 false false false 3 false true false false 732414000 732414 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 631474000 631474 false false false xbrli:monetaryItemType monetary Total obligations incurred as part of normal operations that are expected to be paid during the following twelve months or within one business cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 21 -Article 5 true 1746 CAPITALIZATION: 2 us-gaap_CapitalizationLongtermDebtAndEquityAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 1747 Common stockholder's equity 2 us-gaap_StockholdersEquity us-gaap true credit instant No definition available. false false false false false false false false false false false terselabel false 1 false true false false 3731382000 3731382 false false false 2 false false false false 0 0 false false false 3 false true false false 3731382000 3731382 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 3514571000 3514571 false false false xbrli:monetaryItemType monetary Total of all Stockholders' Equity (deficit) items, net of receivables from officers, directors owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph A3 -Appendix A Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 4 -Section E Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29, 30, 31 -Article 5 false 1748 Long-term debt and other long-term obligations 2 us-gaap_LongTermDebtAndCapitalLeaseObligations us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 1518968000 1518968 false false false 2 false false false false 0 0 false false false 3 false true false false 1518968000 1518968 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 1519339000 1519339 false false false xbrli:monetaryItemType monetary Sum of the carrying values as of the balance sheet date of all long-term debt, which is debt initially having maturities due after one year from the balance sheet date or beyond the operating cycle, if longer, but excluding the portions thereof scheduled to be repaid within one year or the normal operating cycle, if longer plus capital lease obligations due to be paid more than one year after the balance sheet date. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 6 -Section H true 1749 Total capitalization 2 fe_TotalCapitalization fe false credit instant Total Capitalization. false false false false false false false false false false false totallabel false 1 false true false false 5250350000 5250350 false false false 2 false false false false 0 0 false false false 3 false true false false 5250350000 5250350 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 5033910000 5033910 false false false xbrli:monetaryItemType monetary Total Capitalization. No authoritative reference available. true 1750 NONCURRENT LIABILITIES: 2 us-gaap_LiabilitiesNoncurrentAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 1751 Deferred gain on sale and leaseback transaction 2 us-gaap_SaleLeasebackTransactionDeferredGainNet us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary The portion of the gain that will be recorded as income or a reduction in rent expense in future periods less amounts recognized in the current period. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 13 -Paragraph 33 false 1752 Accumulated deferred income taxes 2 us-gaap_DeferredTaxLiabilitiesNoncurrent us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Represents the noncurrent portion of deferred tax liabilities, which result from applying the applicable tax rate to net taxable temporary differences pertaining to each jurisdiction to which the entity is obligated to pay income tax. A noncurrent taxable temporary difference is a difference between the tax basis and the carrying amount of a noncurrent asset or liability in the financial statements prepared in accordance with generally accepted accounting principles. In a classified statement of financial position, an enterprise shall separate deferred tax liabilities and assets into a current amount and a noncurrent amount. Deferred tax liabilities and assets shall be classified as current or noncurrent based on the classification of the related asset or liability for financial reporting. A deferred tax liability or asset that is not related to an asset or liability for financial reporting, including deferred tax assets related to carryforwards, shall be classified according to the expected reversal date of the temporary difference. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Paragraph 41, 42 false 1753 Accumulated deferred investment tax credits 2 us-gaap_AccumulatedDeferredInvestmentTaxCredit us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary The noncurrent portion of the reserve for accumulated deferred investment tax credits as of the balance sheet date. This is the remaining investment credit, which will reduce the cost of services collected from ratepayers by a ratable portion over the investment's regulatory life. No authoritative reference available. false 1754 Asset retirement obligations 2 us-gaap_AssetRetirementObligationsNoncurrent us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Noncurrent portion of the carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 143 -Paragraph 3, 10, 22 false 1755 Retirement benefits 2 us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansNoncurrentLiabilities us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 35830000 35830 false false false 2 false false false false 0 0 false false false 3 false true false false 35830000 35830 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 33144000 33144 false false false xbrli:monetaryItemType monetary For classified balance sheets this represents the noncurrent liability for underfunded plans recognized in the balance sheet that is associated with the defined benefit pension plans and other postretirement defined benefit plans. For unclassified balance sheets, this represents the entire liability recognized in the balance sheet that is associated with the defined benefit plans. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph c Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 6 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 3 false 1756 Property taxes 2 fe_PropertyTaxesNoncurrentLiabilities fe false credit instant Property taxes. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary Property taxes. No authoritative reference available. false 1757 Lease market valuation liability 2 us-gaap_OffMarketLeaseUnfavorable us-gaap true credit instant No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary This element represents a liability associated with the acquisition of an off-market lease when the terms of the lease are unfavorable to the market terms for the lease at the date of acquisition. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141 -Paragraph 37 false 1758 Other 2 us-gaap_OtherLiabilitiesNoncurrent us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 119635000 119635 false false false 2 false false false false 0 0 false false false 3 false true false false 119635000 119635 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 122599000 122599 false false false xbrli:monetaryItemType monetary Aggregate carrying amount, as of the balance sheet date, of noncurrent obligations not separately disclosed in the balance sheet due to materiality considerations. Noncurrent liabilities are expected to be paid after one year (or the normal operating cycle, if longer). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 24 -Article 5 true 1759 Total noncurrent liabilities 2 us-gaap_LiabilitiesNoncurrent us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 155465000 155465 false false false 2 false false false false 0 0 false false false 3 false true false false 155465000 155465 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 155743000 155743 false false false xbrli:monetaryItemType monetary Total obligations incurred as part of normal operations that is expected to be repaid beyond the following twelve months or one business cycle. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22, 23, 24, 25, 26, 27 -Article 5 true 1760 Total liabilities and capitalization 2 us-gaap_LiabilitiesAndStockholdersEquity us-gaap true credit instant No definition available. false false false false false false false false false false false totallabel false 1 false true false false 6138229000 6138229 false false false 2 false false false false 0 0 false false false 3 false true false false 6138229000 6138229 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 5821127000 5821127 false false false xbrli:monetaryItemType monetary Total of all Liabilities and Stockholders' Equity items. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 32 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 25 -Article 7 true 1761 Statements of Cash Flows [Abstract] 2 us-gaap_StatementOfCashFlowsAbstract us-gaap true na duration No definition available. false false false false false true false false false false false false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 1762 NET CASH PROVIDED FROM (USED FOR) OPERATING ACTIVITIES 2 us-gaap_NetCashProvidedByUsedInOperatingActivities us-gaap true na duration No definition available. false false false false false false false false false false false terselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -223072000 -223072 false false false 4 false true false false 285284000 285284 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net cash from (used in) all of the entity's operating activities, including those of discontinued operations, of the reporting entity. Operating activities generally involve producing and delivering goods and providing services. Operating activity cash flows include transactions, adjustments, and changes in value that are not defined as investing or financing activities. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 26 false 1763 New Financing- 2 fe_NewFinancingAbstract fe false na duration New Financing Abstract. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string New Financing Abstract. false 1764 Long-term debt 2 us-gaap_ProceedsFromIssuanceOfLongTermDebt us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 19 -Subparagraph b false 1765 Short-term borrowings, net 2 us-gaap_ProceedsFromShortTermDebt us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false 98880000 98880 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash inflow from a borrowing having initial term of repayment within one year or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 19 -Subparagraph b false 1766 Redemptions and Repayments- 2 fe_RedemptionsAndRepaymentsAbstract fe false na duration Redemptions And Repayments Abstract. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string Redemptions And Repayments Abstract. false 1767 Long-term debt 2 us-gaap_RepaymentsOfLongTermDebt us-gaap true credit duration No definition available. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -397000 -397 false false false 4 false true false false -1696000 -1696 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 20 -Subparagraph b false 1768 Short-term borrowings, net 2 us-gaap_RepaymentsOfShortTermDebt us-gaap true credit duration No definition available. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash outflow for a borrowing having initial term of repayment within one year or the normal operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 20 -Subparagraph b false 1769 Other 2 us-gaap_ProceedsFromPaymentsForOtherFinancingActivities us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -457000 -457 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net cash inflow (outflow) from other financing activities. This element is used when there is not a more specific and appropriate element in the taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18, 19, 20 true 1770 Net cash used for financing activities 2 us-gaap_NetCashProvidedByUsedInFinancingActivities us-gaap true debit duration No definition available. false false false false false false false false false false false terselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -854000 -854 false false false 4 false true false false 97184000 97184 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net cash inflow (outflow) from financing activity for the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 26 false 1771 CASH FLOWS FROM INVESTING ACTIVITIES: 2 us-gaap_NetCashProvidedByUsedInInvestingActivitiesAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 1772 Property additions 2 us-gaap_PaymentsToAcquireProductiveAssets us-gaap true credit duration No definition available. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -3716000 -3716 false false false 4 false true false false -694000 -694 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash outflow for purchases of and capital improvements on property, plant and equipment (capital expenditures), software, and other intangible assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 17 -Subparagraph c false 1773 Proceeds from asset sales 2 us-gaap_ProceedsFromSaleOfOtherProductiveAssets us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash inflow from the sale of other tangible or intangible assets used to produce goods or deliver services not otherwise defined in the taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 16 -Subparagraph c false 1774 Sales of investment securities held in trusts 2 us-gaap_ProceedsFromSaleOfAvailableForSaleSecurities us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash inflow associated with the sale of debt and equity securities classified as available-for-sale securities. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 16 -Subparagraph a Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 18 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 16 -Subparagraph b false 1775 Purchases of investment securities held in trusts 2 us-gaap_PaymentsToAcquireAvailableForSaleSecurities us-gaap true credit duration No definition available. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash outflow to acquire debt and equity securities not classified as either held-to-maturity securities or trading securities which would be classified as available-for-sale securities and reported at fair value, with unrealized gains and losses excluded from earnings and reported in a separate component of shareholders' equity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 17 -Subparagraph b Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 18 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 17 -Subparagraph a false 1776 Loans from associated companies, net 2 us-gaap_ProceedsFromPaymentsForLongTermLoansForRelatedParties us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 332067000 332067 false false false 4 false true false false -261839000 -261839 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash inflow or outflow associated with long-term loans for related parties where one party can exercise control or significant influence over another party, including affiliates, owners or officers and their immediate families, pension trusts, and so forth. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15, 16, 17 false 1777 Customer acquisition costs 2 us-gaap_PaymentsToAcquireIntangibleAssets us-gaap true credit duration No definition available. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false -104795000 -104795 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash outflow to acquire asset without physical form usually arising from contractual or other legal rights, excluding goodwill. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 17 -Subparagraph c false 1778 Leasehold improvement payments to associated companies 2 fe_LeaseholdImprovementPaymentsToAssociatedCompanies fe false credit duration Leasehold improvement payments to associated companies. false false false false false false false false false false true negated false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Leasehold improvement payments to associated companies. No authoritative reference available. false 1779 Other 2 us-gaap_PaymentsForProceedsFromOtherInvestingActivities us-gaap true credit duration No definition available. false false false false false false false false false false true negatedtotal false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 370000 370 false false false 4 false true false false 65000 65 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net cash outflow (inflow) from other investing activities. This element is used when there is not a more specific and appropriate element in the taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 true 1780 Net cash used for investing activities 2 us-gaap_NetCashProvidedByUsedInInvestingActivities us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 223926000 223926 false false false 4 false true false false -262468000 -262468 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net cash inflow (outflow) from investing activity. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 26 true 1781 Net change in cash and cash equivalents 2 us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease us-gaap true na duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false 120000000 120000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary The net change between the beginning and ending balance of cash and cash equivalents. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 26 false 1782 Cash and cash equivalents at beginning of period 2 us-gaap_CashAndCashEquivalentsAtCarryingValue us-gaap true debit instant No definition available. false false false false false false false false true false false periodstartlabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false true false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits should not be reported as cash and cash equivalents. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7, 26 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 8, 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7 -Footnote 1 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 false 1783 Cash and cash equivalents at end of period 2 us-gaap_CashAndCashEquivalentsAtCarryingValue us-gaap true debit instant No definition available. false false false false false false false false false true false periodendlabel false 1 true true false false 0 0 false false false 2 true true false false 120000000 120000 false false false 3 true true false false 0 0 false false false 4 true true false false 120000000 120000 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:monetaryItemType monetary Includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits should not be reported as cash and cash equivalents. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7, 26 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 8, 9 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 7 -Footnote 1 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 1 -Article 5 false 1 * Includes excise tax collections of $99 million and $95 million in the three months ended June 30, 2010 and 2009, respectively, and $208 million and $204 million in the six months ended June 30, 2010 and 2009, respectively. 6 621 false Thousands UnKnown UnKnown false true