2.2.0.7 true Supplemental Guarantor Information (Details) (USD $) 00613 - 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 Pure Standard http://www.xbrl.org/2003/instance pure xbrli 0 $ false 2 USD false false USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 EPS Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 $ false 3 USD false false USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 Pure Standard http://www.xbrl.org/2003/instance pure xbrli 0 EPS Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 $ false 4 USD false false USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 EPS Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 $ false 5 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 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 3693000000 3693000 [1] false false false 2 true true false false 3408000000 3408000 [1] false false false 3 true true false false 10122000000 10122000 [1] false false false 4 true true false false 10013000000 10013000 [1] false false false 5 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 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 400000000 400000 false false false 2 false true false false 302000000 302000 false false false 3 false true false false 1084000000 1084000 false false false 4 false true false false 890000000 890000 false false false 5 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 7 Purchased power from non-affiliates 2 us-gaap_CostOfPurchasedPower us-gaap true debit duration No definition available. false false false false false false false false false false false terselabel false 1 false true false false 1284000000 1284000 false false false 2 false true false false 1313000000 1313000 false false false 3 false true false false 3574000000 3574000 false false false 4 false true false false 3480000000 3480000 false false false 5 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 8 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 738000000 738000 false false false 2 false true false false 665000000 665000 false false false 3 false true false false 2112000000 2112000 false false false 4 false true false false 2103000000 2103000 false false false 5 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 9 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 182000000 182000 false false false 2 false true false false 188000000 188000 false false false 3 false true false false 565000000 565000 false false false 4 false true false false 550000000 550000 false false false 5 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 10 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 verboselabel false 1 false true false false 206000000 206000 false false false 2 false true false false 192000000 192000 false false false 3 false true false false 587000000 587000 false false false 4 false true false false 587000000 587000 false false false 5 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. false 11 Impairment of long-lived assets 2 us-gaap_UtilitiesOperatingExpenseImpairments 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 292000000 292000 false false false 2 false false false false 0 0   false false false 3 false true false false 294000000 294000 false false false 4 false false false false 0 0   false false false 5 false false false false 0 0 false false false xbrli:monetaryItemType monetary Discloses the amount of operating expense for the period related to impairments. 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 3278000000 3278000 false false false 2 false true false false 2921000000 2921000 false false false 3 false true false false 8765000000 8765000 false false false 4 false true false false 8377000000 8377000 false false false 5 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 415000000 415000 false false false 2 false true false false 487000000 487000 false false false 3 false true false false 1357000000 1357000 false false false 4 false true false false 1636000000 1636000 false false false 5 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 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 46000000 46000 false false false 2 false true false false 191000000 191000 false false false 3 false true false false 93000000 93000 false false false 4 false true false false 207000000 207000 false false false 5 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 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 -208000000 -208000 false false false 2 false true false false -355000000 -355000 false false false 3 false true false false -628000000 -628000 false false false 4 false true false false -755000000 -755000 false false false 5 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 41000000 41000 false false false 2 false true false false 35000000 35000 false false false 3 false true false false 122000000 122000 false false false 4 false true false false 96000000 96000 false false false 5 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 -121000000 -121000 false false false 2 false true false false -129000000 -129000 false false false 3 false true false false -413000000 -413000 false false false 4 false true false false -452000000 -452000 false false false 5 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 294000000 294000 false false false 2 false true false false 358000000 358000 false false false 3 false true false false 944000000 944000 false false false 4 false true false false 1184000000 1184000 false false false 5 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 119000000 119000 false false false 2 false true false false 128000000 128000 false false false 3 false true false false 364000000 364000 false false false 4 false true false false 430000000 430000 false false false 5 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 175000000 175000 false false false 2 false true false false 230000000 230000 false false false 3 false true false false 580000000 580000 false false false 4 false true false false 754000000 754000 false false false 5 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 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 true false false 632000000 632000 false false false 2 false true false false 838000000 838000 false false false 3 false true false false 632000000 632000 false false false 4 false true false false 838000000 838000 false false false 5 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 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 xbrli:stringItemType string No definition available. false 29 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 1414000000 1414000 false false false 2 false false false false 0 0 false false false 3 false true false false 1414000000 1414000 false false false 4 false false false false 0 0 false false false 5 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 true false false 150000000 150000 false false false 2 false false false false 0 0 false false false 3 false true false false 150000000 150000 false false false 4 false false false false 0 0 false false false 5 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 true false false 652000000 652000 false false false 2 false false false false 0 0 false false false 3 false true false false 652000000 652000 false false false 4 false false false false 0 0 false false false 5 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 true false false 252000000 252000 false false false 2 false false false false 0 0 false false false 3 false true false false 252000000 252000 false false false 4 false false false false 0 0 false false false 5 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 true false false 3391000000 3391000 false false false 2 false false false false 0 0 false false false 3 false true false false 3391000000 3391000 false false false 4 false false false false 0 0 false false false 5 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 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 true false false 27590000000 27590000 false false false 2 false false false false 0 0 false false false 3 false true false false 27590000000 27590000 false false false 4 false false false false 0 0 false false false 5 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 true false false 11206000000 11206000 false false false 2 false false false false 0 0 false false false 3 false true false false 11206000000 11206000 false false false 4 false false false false 0 0 false false false 5 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 true false false 16384000000 16384000 false false false 2 false false false false 0 0 false false false 3 false true false false 16384000000 16384000 false false false 4 false false false false 0 0 false false false 5 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 true false false 3154000000 3154000 false false false 2 false false false false 0 0 false false false 3 false true false false 3154000000 3154000 false false false 4 false false false false 0 0 false false false 5 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 true false false 19538000000 19538000 false false false 2 false false false false 0 0 false false false 3 false true false false 19538000000 19538000 false false false 4 false false false false 0 0 false false false 5 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 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 true false false 1965000000 1965000 false false false 2 false false false false 0 0 false false false 3 false true false false 1965000000 1965000 false false false 4 false false false false 0 0 false false false 5 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 true false false 564000000 564000 false false false 2 false false false false 0 0 false false false 3 false true false false 564000000 564000 false false false 4 false false false false 0 0 false false false 5 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 true false false 3015000000 3015000 false false false 2 false false false false 0 0 false false false 3 false true false false 3015000000 3015000 false false false 4 false false false false 0 0 false false false 5 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 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 true false false 5575000000 5575000 false false false 2 false false false false 0 0 false false false 3 false true false false 5575000000 5575000 false false false 4 false false false false 0 0 false false false 5 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 true false false 127000000 127000 false false false 2 false false false false 0 0 false false false 3 false true false false 127000000 127000 false false false 4 false false false false 0 0 false false false 5 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 true false false 826000000 826000 false false false 2 false false false false 0 0 false false false 3 false true false false 826000000 826000 false false false 4 false false false false 0 0 false false false 5 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 true false false 8763000000 8763000 false false false 2 false false false false 0 0 false false false 3 false true false false 8763000000 8763000 false false false 4 false false false false 0 0 false false false 5 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 true false false 34707000000 34707000 false false false 2 false false false false 0 0 false false false 3 false true false false 34707000000 34707000 false false false 4 false false false false 0 0 false false false 5 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 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 true false false 1590000000 1590000 false false false 2 false false false false 0 0 false false false 3 false true false false 1590000000 1590000 false false false 4 false false false false 0 0 false false false 5 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 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 true false false 1000000000 1000000 false false false 2 false false false false 0 0 false false false 3 false true false false 1000000000 1000000 false false false 4 false false false false 0 0 false false false 5 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 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 true false false 813000000 813000 false false false 2 false false false false 0 0 false false false 3 false true false false 813000000 813000 false false false 4 false false false false 0 0 false false false 5 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 true false false 230000000 230000 false false false 2 false false false false 0 0 false false false 3 false true false false 230000000 230000 false false false 4 false false false false 0 0 false false false 5 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 true false false 1339000000 1339000 false false false 2 false false false false 0 0 false false false 3 false true false false 1339000000 1339000 false false false 4 false false false false 0 0 false false false 5 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 true false false 4972000000 4972000 false false false 2 false false false false 0 0 false false false 3 false true false false 4972000000 4972000 false false false 4 false false false false 0 0 false false false 5 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 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 true false false 8717000000 8717000 false false false 2 false false false false 0 0 false false false 3 false true false false 8717000000 8717000 false false false 4 false false false false 0 0 false false false 5 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 true false false 12104000000 12104000 false false false 2 false false false false 0 0 false false false 3 false true false false 12104000000 12104000 false false false 4 false false false false 0 0 false false false 5 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 true false false 20795000000 20795000 false false false 2 false false false false 0 0 false false false 3 false true false false 20795000000 20795000 false false false 4 false false false false 0 0 false false false 5 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 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 true false false 968000000 968000 false false false 2 false false false false 0 0 false false false 3 false true false false 968000000 968000 false false false 4 false false false false 0 0 false false false 5 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 true false false 2824000000 2824000 false false false 2 false false false false 0 0 false false false 3 false true false false 2824000000 2824000 false false false 4 false false false false 0 0 false false false 5 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 true false false 1394000000 1394000 false false false 2 false false false false 0 0 false false false 3 false true false false 1394000000 1394000 false false false 4 false false false false 0 0 false false false 5 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 true false false 228000000 228000 false false false 2 false false false false 0 0 false false false 3 false true false false 228000000 228000 false false false 4 false false false false 0 0 false false false 5 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 true false false 1229000000 1229000 false false false 2 false false false false 0 0 false false false 3 false true false false 1229000000 1229000 false false false 4 false false false false 0 0 false false false 5 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 true false false 8940000000 8940000 false false false 2 false false false false 0 0 false false false 3 false true false false 8940000000 8940000 false false false 4 false false false false 0 0 false false false 5 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 true false false 34707000000 34707000 false false false 2 false false false false 0 0 false false false 3 false true false false 34707000000 34707000 false false false 4 false false false false 0 0 false false false 5 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 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 2073000000 2073000 false false false 4 false true false false 1464000000 1464000 false false false 5 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 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 251000000 251000 false false false 4 false true false false 4151000000 4151000 false false false 5 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 87 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 xbrli:stringItemType string Redemptions And Repayments Abstract. false 88 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 -422000000 -422000 false false false 4 false true false false -2213000000 -2213000 false false false 5 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 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 -171000000 -171000 false false false 4 false true false false -764000000 -764000 false false false 5 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 90 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 -25000000 -25000 false false false 4 false true false false -54000000 -54000 false false false 5 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 91 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 -870000000 -870000 false false false 4 false true false false 617000000 617000 false false false 5 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 92 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 xbrli:stringItemType string No definition available. false 93 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 -1467000000 -1467000 false false false 4 false true false false -1575000000 -1575000 false false false 5 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 94 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 117000000 117000 false false false 4 false true false false 19000000 19000 false false false 5 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 95 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 2577000000 2577000 false false false 4 false true false false 3039000000 3039000 false false false 5 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 96 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 -2610000000 -2610000 false false false 4 false true false false -3101000000 -3101000 false false false 5 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 98 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 -110000000 -110000 false false false 4 false false false false 0 0   false false false 5 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 101 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 -8000000 -8000 false false false 4 false true false false -16000000 -16000 false false false 5 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 102 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 -1445000000 -1445000 false false false 4 false true false false -1788000000 -1788000 false false false 5 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 103 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 -242000000 -242000 false false false 4 false true false false 293000000 293000 false false false 5 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 104 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 874000000 874000 false false false 4 false true false false 545000000 545000 false false false 5 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 105 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 632000000 632000 false false false 2 false true false false 838000000 838000 false false false 3 false true false false 632000000 632000 false false false 4 false true false false 838000000 838000 false false false 5 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 108 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 false 6 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 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 $ na No definition available. No authoritative reference available. false 109 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 xbrli:stringItemType string No definition available. false 110 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 380542000 380542 false false false 2 false true false false 170129000 170129 false false false 3 false true false false 1145795000 1145795 false false false 4 false true false false 955452000 955452 false false false 5 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 111 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 xbrli:stringItemType string No definition available. false 112 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 48675000 48675 false false false 2 false true false false 43462000 43462 false false false 3 false true false false 125212000 125212 false false false 4 false true false false 99128000 99128 false false false 5 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 113 Purchased power from affiliates 2 fe_CostOfPurchasedPowerFromAffiliates fe false debit duration Purchased power from affiliates. false false false false false false false false false false false verboselabel false 1 false true false false 56763000 56763 false false false 2 false true false false 35290000 35290 false false false 3 false true false false 167173000 167173 false false false 4 false true false false 149746000 149746 false false false 5 false false false false 0 0 false false false xbrli:monetaryItemType monetary Purchased power from affiliates. No authoritative reference available. false 114 Purchased power from non-affiliates 2 us-gaap_CostOfPurchasedPower 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 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 xbrli:monetaryItemType monetary Cost of electricity purchased and sold during the reporting period. No authoritative reference available. false 115 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 116112000 116112 false false false 2 false true false false 113669000 113669 false false false 3 false true false false 371882000 371882 false false false 4 false true false false 397284000 397284 false false false 5 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 116 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 36005000 36005 false false false 2 false true false false 35832000 35832 false false false 3 false true false false 109364000 109364 false false false 4 false true false false 103135000 103135 false false false 5 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 117 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 verboselabel false 1 false true false false 6713000 6713 false false false 2 false true false false 6018000 6018 false false false 3 false true false false 20688000 20688 false false false 4 false true false false 18246000 18246 false false false 5 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. false 118 Impairment of long-lived assets 2 us-gaap_UtilitiesOperatingExpenseImpairments 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 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 xbrli:monetaryItemType monetary Discloses the amount of operating expense for the period related to impairments. No authoritative reference available. true 119 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 264268000 264268 false false false 2 false true false false 234271000 234271 false false false 3 false true false false 794319000 794319 false false false 4 false true false false 767539000 767539 false false false 5 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 120 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 116274000 116274 false false false 2 false true false false -64142000 -64142 false false false 3 false true false false 351476000 351476 false false false 4 false true false false 187913000 187913 false false false 5 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 121 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 xbrli:stringItemType string Other Income Expense Abstract. false 122 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 29243000 29243 false false false 2 false true false false 158503000 158503 false false false 3 false true false false 39483000 39483 false false false 4 false true false false 134882000 134882 false false false 5 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 123 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 xbrli:stringItemType string Miscellaneous income expense Abstact. false 124 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 49000 49 false false false 2 false true false false 1000 1 false false false 3 false true false false 50000 50 false false false 4 false true false false 15000 15 false false false 5 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 125 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 -416000 -416 false false false 2 false true false false -907000 -907 false false false 3 false true false false -1266000 -1266 false false false 4 false true false false -3752000 -3752 false false false 5 false false false false 0 0 false false false xbrli:monetaryItemType monetary Interest expense to affiliates No authoritative reference available. false 126 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 -15028000 -15028 false false false 2 false true false false -16205000 -16205 false false false 3 false true false false -46152000 -46152 false false false 4 false true false false -46050000 -46050 false false false 5 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 127 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 3836000 3836 false false false 2 false true false false 2439000 2439 false false false 3 false true false false 11327000 11327 false false false 4 false true false false 7572000 7572 false false false 5 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 128 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 17684000 17684 false false false 2 false true false false 143831000 143831 false false false 3 false true false false 3442000 3442 false false false 4 false true false false 92667000 92667 false false false 5 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 129 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 133958000 133958 false false false 2 false true false false 79689000 79689 false false false 3 false true false false 354918000 354918 false false false 4 false true false false 280580000 280580 false false false 5 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 130 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 51600000 51600 false false false 2 false true false false 27801000 27801 false false false 3 false true false false 130163000 130163 false false false 4 false true false false 98893000 98893 false false false 5 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 131 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 82358000 82358 false false false 2 false true false false 51888000 51888 false false false 3 false true false false 224755000 224755 false false false 4 false true false false 181687000 181687 false false false 5 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 132 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 xbrli:stringItemType string No definition available. false 133 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 false false false 0 0   false false false 3 false true false false 9000 9 false false false 4 false false false false 0 0   false false false 5 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 134 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 xbrli:stringItemType string No definition available. false 135 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 112523000 112523 false false false 2 false false false false 0 0 false false false 3 false true false false 112523000 112523 false false false 4 false false false false 0 0 false false false 5 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 136 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 false 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 137 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 18524000 18524 false false false 2 false false false false 0 0 false false false 3 false true false false 18524000 18524 false false false 4 false false false false 0 0 false false false 5 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 138 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 162087000 162087 false false false 2 false false false false 0 0 false false false 3 false true false false 162087000 162087 false false false 4 false false false false 0 0 false false false 5 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 139 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 223871000 223871 false false false 2 false false false false 0 0 false false false 3 false true false false 223871000 223871 false false false 4 false false false false 0 0 false false false 5 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 140 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 2973000 2973 false false false 2 false false false false 0 0 false false false 3 false true false false 2973000 2973 false false false 4 false false false false 0 0 false false false 5 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 141 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 519987000 519987 false false false 2 false false false false 0 0 false false false 3 false true false false 519987000 519987 false false false 4 false false false false 0 0 false false false 5 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 142 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 xbrli:stringItemType string No definition available. false 143 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 5313456000 5313456 false false false 2 false false false false 0 0 false false false 3 false true false false 5313456000 5313456 false false false 4 false false false false 0 0 false false false 5 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 144 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 2098927000 2098927 false false false 2 false false false false 0 0 false false false 3 false true false false 2098927000 2098927 false false false 4 false false false false 0 0 false false false 5 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 145 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 3214529000 3214529 false false false 2 false false false false 0 0 false false false 3 false true false false 3214529000 3214529 false false false 4 false false false false 0 0 false false false 5 false true false false 3264134000 3264134 false false false xbrli:monetaryItemType monetary Net Plant Excluding Construction Work In Progress. No authoritative reference available. false 146 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 507842000 507842 false false false 2 false false false false 0 0 false false false 3 false true false false 507842000 507842 false false false 4 false false false false 0 0 false false false 5 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 147 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 3722371000 3722371 false false false 2 false false false false 0 0 false false false 3 false true false false 3722371000 3722371 false false false 4 false false false false 0 0 false false false 5 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 148 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 xbrli:stringItemType string No definition available. false 149 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 1158376000 1158376 false false false 2 false false false false 0 0 false false false 3 false true false false 1158376000 1158376 false false false 4 false false false false 0 0 false false false 5 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 150 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 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 xbrli:monetaryItemType monetary Investment in associated companies. No authoritative reference available. false 151 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 201000 201 false false false 2 false false false false 0 0 false false false 3 false true false false 201000 201 false false false 4 false false false false 0 0 false false false 5 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 152 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 1158577000 1158577 false false false 2 false false false false 0 0 false false false 3 false true false false 1158577000 1158577 false false false 4 false false false false 0 0 false false false 5 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 153 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 xbrli:stringItemType string Deferred Charges And Other Assets Abstract. false 154 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 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 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 155 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 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 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 156 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 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 157 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 true false false 22314000 22314 false false false xbrli:monetaryItemType monetary Property taxes. No authoritative reference available. false 158 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 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 xbrli:monetaryItemType monetary Unamortized sale and leaseback costs. No authoritative reference available. false 159 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 7842000 7842 false false false 2 false false false false 0 0 false false false 3 false true false false 7842000 7842 false false false 4 false false false false 0 0 false false false 5 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 160 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 30156000 30156 false false false 2 false false false false 0 0 false false false 3 false true false false 30156000 30156 false false false 4 false false false false 0 0 false false false 5 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 161 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 5431091000 5431091 false false false 2 false false false false 0 0 false false false 3 false true false false 5431091000 5431091 false false false 4 false false false false 0 0 false false false 5 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 162 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 xbrli:stringItemType string No definition available. false 163 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 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 164 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 xbrli:stringItemType string No definition available. false 165 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 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 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 166 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 false 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 167 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 xbrli:stringItemType string No definition available. false 168 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 227328000 227328 false false false 2 false false false false 0 0 false false false 3 false true false false 227328000 227328 false false false 4 false false false false 0 0 false false false 5 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 169 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 false 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 170 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 56535000 56535 false false false 2 false false false false 0 0 false false false 3 false true false false 56535000 56535 false false false 4 false false false false 0 0 false false false 5 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 171 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 28383000 28383 false false false 2 false false false false 0 0 false false false 3 false true false false 28383000 28383 false false false 4 false false false false 0 0 false false false 5 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 172 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 1240018000 1240018 false false false 2 false false false false 0 0 false false false 3 false true false false 1240018000 1240018 false false false 4 false false false false 0 0 false false false 5 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 173 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 xbrli:stringItemType string No definition available. false 174 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 2362711000 2362711 false false false 2 false false false false 0 0 false false false 3 false true false false 2362711000 2362711 false false false 4 false false false false 0 0 false false false 5 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 175 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 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 176 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 2869244000 2869244 false false false 2 false false false false 0 0 false false false 3 false true false false 2869244000 2869244 false false false 4 false false false false 0 0 false false false 5 false true false false 2674313000 2674313 false false false xbrli:monetaryItemType monetary Total Capitalization. No authoritative reference available. true 177 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 xbrli:stringItemType string No definition available. false 178 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 false 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 179 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 410095000 410095 false false false 2 false false false false 0 0 false false false 3 false true false false 410095000 410095 false false false 4 false false false false 0 0 false false false 5 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 180 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 21217000 21217 false false false 2 false false false false 0 0 false false false 3 false true false false 21217000 21217 false false false 4 false false false false 0 0 false false false 5 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 181 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 851127000 851127 false false false 2 false false false false 0 0 false false false 3 false true false false 851127000 851127 false false false 4 false false false false 0 0 false false false 5 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 182 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 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 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 183 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 true false false 22314000 22314 false false false xbrli:monetaryItemType monetary Property taxes. No authoritative reference available. false 184 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 false 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 185 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 17076000 17076 false false false 2 false false false false 0 0 false false false 3 false true false false 17076000 17076 false false false 4 false false false false 0 0 false false false 5 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 186 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 1321829000 1321829 false false false 2 false false false false 0 0 false false false 3 false true false false 1321829000 1321829 false false false 4 false false false false 0 0 false false false 5 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 187 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 5431091000 5431091 false false false 2 false false false false 0 0 false false false 3 false true false false 5431091000 5431091 false false false 4 false false false false 0 0 false false false 5 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 188 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 xbrli:stringItemType string No definition available. false 189 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 520272000 520272 false false false 4 false true false false 408364000 408364 false false false 5 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 190 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 xbrli:stringItemType string New Financing Abstract. false 191 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 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 192 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 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 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 193 Equity contributions from parent 2 us-gaap_ProceedsFromContributionsFromParent 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 150000000 150000 false false false 5 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash inflow from parent as a source of financing that is recorded as additional paid in capital. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 false 194 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 xbrli:stringItemType string Redemptions And Repayments Abstract. false 195 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 -366857000 -366857 false false false 5 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 196 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 false false false 0 0 false false false 4 false true false false -6347000 -6347 false false false 5 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 197 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 -102000 -102 false false false 4 false true false false -3160000 -3160 false false false 5 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 198 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 -43051000 -43051 false false false 4 false true false false 107601000 107601 false false false 5 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 199 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 xbrli:stringItemType string No definition available. false 200 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 -378595000 -378595 false false false 4 false true false false -400845000 -400845 false false false 5 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 201 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 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 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 202 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 1478086000 1478086 false false false 4 false true false false 2152717000 2152717 false false false 5 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 203 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 -1511273000 -1511273 false false false 4 false true false false -2175135000 -2175135 false false false 5 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 204 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 -14224000 -14224 false false false 4 false true false false -93041000 -93041 false false false 5 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 205 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 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 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 206 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 xbrli:monetaryItemType monetary Leasehold improvement payments to associated companies. No authoritative reference available. false 207 Investment in subsidiary 2 fe_InvestmentInConsolidatedSubsidiary fe false credit duration Investment In Consolidated Subsidiary. 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 false false false 0 0 false false false xbrli:monetaryItemType monetary Investment In Consolidated Subsidiary. No authoritative reference available. false 208 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 -11000 -11 false false false 4 false true false false 339000 339 false false false 5 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 209 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 -477221000 -477221 false false false 4 false true false false -515965000 -515965 false false false 5 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 210 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 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 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 211 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 false false false 0 0   false false false 5 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 212 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 false false false 0 0   false false false 3 false true false false 9000 9 false false false 4 false false false false 0 0   false false false 5 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 215 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 false 11 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 12 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 13 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 14 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 15 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 216 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 xbrli:stringItemType string No definition available. false 217 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 -1012751000 -1012751 false false false 2 false true false false -631227000 -631227 false false false 3 false true false false -2886947000 -2886947 false false false 4 false true false false -2368210000 -2368210 false false false 5 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 218 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 xbrli:stringItemType string No definition available. false 219 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 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 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 220 Purchased power from affiliates 2 fe_CostOfPurchasedPowerFromAffiliates fe false debit duration Purchased power from affiliates. false false false false false false false false false false false verboselabel false 1 false true false false -1012751000 -1012751 false false false 2 false true false false -631229000 -631229 false false false 3 false true false false -2886947000 -2886947 false false false 4 false true false false -2368212000 -2368212 false false false 5 false false false false 0 0 false false false xbrli:monetaryItemType monetary Purchased power from affiliates. No authoritative reference available. false 221 Purchased power from non-affiliates 2 us-gaap_CostOfPurchasedPower 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 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 xbrli:monetaryItemType monetary Cost of electricity purchased and sold during the reporting period. No authoritative reference available. false 222 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 12190000 12190 false false false 2 false true false false 12192000 12192 false false false 3 false true false false 36568000 36568 false false false 4 false true false false 36571000 36571 false false false 5 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 223 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 -1304000 -1304 false false false 2 false true false false -1311000 -1311 false false false 3 false true false false -3920000 -3920 false false false 4 false true false false -3940000 -3940 false false false 5 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 224 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 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 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. false 225 Impairment of long-lived assets 2 us-gaap_UtilitiesOperatingExpenseImpairments 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 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 xbrli:monetaryItemType monetary Discloses the amount of operating expense for the period related to impairments. No authoritative reference available. true 226 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 -1001865000 -1001865 false false false 2 false true false false -620348000 -620348 false false false 3 false true false false -2854299000 -2854299 false false false 4 false true false false -2335581000 -2335581 false false false 5 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 227 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 -10886000 -10886 false false false 2 false true false false -10879000 -10879 false false false 3 false true false false -32648000 -32648 false false false 4 false true false false -32629000 -32629 false false false 5 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 228 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 xbrli:stringItemType string Other Income Expense Abstract. false 229 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 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 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 230 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 xbrli:stringItemType string Miscellaneous income expense Abstact. false 231 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 -3553000 -3553 false false false 2 false true false false -98609000 -98609 false false false 3 false true false false -314591000 -314591 false false false 4 false true false false -498311000 -498311 false false false 5 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 232 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 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 xbrli:monetaryItemType monetary Interest expense to affiliates No authoritative reference available. false 233 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 15885000 15885 false false false 2 false true false false 16113000 16113 false false false 3 false true false false 47933000 47933 false false false 4 false true false false 48605000 48605 false false false 5 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 234 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 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 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 235 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 12332000 12332 false false false 2 false true false false -82496000 -82496 false false false 3 false true false false -266658000 -266658 false false false 4 false true false false -449706000 -449706 false false false 5 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 236 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 1446000 1446 false false false 2 false true false false -93375000 -93375 false false false 3 false true false false -299306000 -299306 false false false 4 false true false false -482335000 -482335 false false false 5 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 237 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 2498000 2498 false false false 2 false true false false 2172000 2172 false false false 3 false true false false 7595000 7595 false false false 4 false true false false 6629000 6629 false false false 5 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 238 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 -1052000 -1052 false false false 2 false true false false -95547000 -95547 false false false 3 false true false false -306901000 -306901 false false false 4 false true false false -488964000 -488964 false false false 5 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 239 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 xbrli:stringItemType string No definition available. false 240 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 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 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 241 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 xbrli:stringItemType string No definition available. false 242 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 -335710000 -335710 false false false 2 false false false false 0 0 false false false 3 false true false false -335710000 -335710 false false false 4 false false false false 0 0 false false false 5 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 243 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 false 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 244 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 false 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 245 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 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 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 246 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 false 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 247 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 false 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 248 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 -335710000 -335710 false false false 2 false false false false 0 0 false false false 3 false true false false -335710000 -335710 false false false 4 false false false false 0 0 false false false 5 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 249 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 xbrli:stringItemType string No definition available. false 250 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 -385006000 -385006 false false false 2 false false false false 0 0 false false false 3 false true false false -385006000 -385006 false false false 4 false false false false 0 0 false false false 5 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 251 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 -174416000 -174416 false false false 2 false false false false 0 0 false false false 3 false true false false -174416000 -174416 false false false 4 false false false false 0 0 false false false 5 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 252 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 -210590000 -210590 false false false 2 false false false false 0 0 false false false 3 false true false false -210590000 -210590 false false false 4 false false false false 0 0 false false false 5 false true false false -214511000 -214511 false false false xbrli:monetaryItemType monetary Net Plant Excluding Construction Work In Progress. No authoritative reference available. false 253 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 false 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 254 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 -210590000 -210590 false false false 2 false false false false 0 0 false false false 3 false true false false -210590000 -210590 false false false 4 false false false false 0 0 false false false 5 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 255 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 xbrli:stringItemType string No definition available. false 256 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 false 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 257 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 -4825221000 -4825221 false false false 2 false false false false 0 0 false false false 3 false true false false -4825221000 -4825221 false false false 4 false false false false 0 0 false false false 5 false true false false -4477602000 -4477602 false false false xbrli:monetaryItemType monetary Investment in associated companies. No authoritative reference available. false 258 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 false 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 259 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 -4825221000 -4825221 false false false 2 false false false false 0 0 false false false 3 false true false false -4825221000 -4825221 false false false 4 false false false false 0 0 false false false 5 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 260 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 xbrli:stringItemType string Deferred Charges And Other Assets Abstract. false 261 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 -470205000 -470205 false false false 2 false false false false 0 0 false false false 3 false true false false -470205000 -470205 false false false 4 false false false false 0 0 false false false 5 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 262 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 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 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 263 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 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 264 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 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 xbrli:monetaryItemType monetary Property taxes. No authoritative reference available. false 265 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 61934000 61934 false false false 2 false false false false 0 0 false false false 3 false true false false 61934000 61934 false false false 4 false false false false 0 0 false false false 5 false true false false 56099000 56099 false false false xbrli:monetaryItemType monetary Unamortized sale and leaseback costs. No authoritative reference available. false 266 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 -60582000 -60582 false false false 2 false false false false 0 0 false false false 3 false true false false -60582000 -60582 false false false 4 false false false false 0 0 false false false 5 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 267 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 -468853000 -468853 false false false 2 false false false false 0 0 false false false 3 false true false false -468853000 -468853 false false false 4 false false false false 0 0 false false false 5 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 268 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 -5840374000 -5840374 false false false 2 false false false false 0 0 false false false 3 false true false false -5840374000 -5840374 false false false 4 false false false false 0 0 false false false 5 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 269 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 xbrli:stringItemType string No definition available. false 270 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 -19102000 -19102 false false false 2 false false false false 0 0 false false false 3 false true false false -19102000 -19102 false false false 4 false false false false 0 0 false false false 5 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 271 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 xbrli:stringItemType string No definition available. false 272 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 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 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 273 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 false 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 274 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 xbrli:stringItemType string No definition available. false 275 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 -305419000 -305419 false false false 2 false false false false 0 0 false false false 3 false true false false -305419000 -305419 false false false 4 false false false false 0 0 false false false 5 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 276 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 false 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 277 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 -45823000 -45823 false false false 2 false false false false 0 0 false false false 3 false true false false -45823000 -45823 false false false 4 false false false false 0 0 false false false 5 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 278 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 38109000 38109 false false false 2 false false false false 0 0 false false false 3 false true false false 38109000 38109 false false false 4 false false false false 0 0 false false false 5 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 279 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 -332235000 -332235 false false false 2 false false false false 0 0 false false false 3 false true false false -332235000 -332235 false false false 4 false false false false 0 0 false false false 5 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 280 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 xbrli:stringItemType string No definition available. false 281 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 -4805933000 -4805933 false false false 2 false false false false 0 0 false false false 3 false true false false -4805933000 -4805933 false false false 4 false false false false 0 0 false false false 5 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 282 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 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 283 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 -6065627000 -6065627 false false false 2 false false false false 0 0 false false false 3 false true false false -6065627000 -6065627 false false false 4 false false false false 0 0 false false false 5 false true false false -5735333000 -5735333 false false false xbrli:monetaryItemType monetary Total Capitalization. No authoritative reference available. true 284 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 xbrli:stringItemType string No definition available. false 285 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 967583000 967583 false false false 2 false false false false 0 0 false false false 3 false true false false 967583000 967583 false false false 4 false false false false 0 0 false false false 5 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 286 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 -410095000 -410095 false false false 2 false false false false 0 0 false false false 3 false true false false -410095000 -410095 false false false 4 false false false false 0 0 false false false 5 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 287 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 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 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 288 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 false 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 289 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 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 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 290 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 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 xbrli:monetaryItemType monetary Property taxes. No authoritative reference available. false 291 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 false 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 292 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 false 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 293 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 557488000 557488 false false false 2 false false false false 0 0 false false false 3 false true false false 557488000 557488 false false false 4 false false false false 0 0 false false false 5 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 294 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 -5840374000 -5840374 false false false 2 false false false false 0 0 false false false 3 false true false false -5840374000 -5840374 false false false 4 false false false false 0 0 false false false 5 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 295 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 xbrli:stringItemType string No definition available. false 296 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 -8732000 -8732 false false false 5 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 297 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 xbrli:stringItemType string New Financing Abstract. false 298 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 false false false 0 0   false false false 5 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 299 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 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 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 300 Equity contributions from parent 2 us-gaap_ProceedsFromContributionsFromParent 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 -250000000 -250000 false false false 5 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash inflow from parent as a source of financing that is recorded as additional paid in capital. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 false 301 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 xbrli:stringItemType string Redemptions And Repayments Abstract. false 302 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 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 303 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 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 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 304 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 false false false 0 0   false false false 4 false true false false -2000 -2 false false false 5 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 305 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 -241268000 -241268 false false false 5 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 306 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 xbrli:stringItemType string No definition available. false 307 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 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 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 308 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 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 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 309 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 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 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 310 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 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 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 311 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 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 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 312 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 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 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 313 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 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 xbrli:monetaryItemType monetary Leasehold improvement payments to associated companies. No authoritative reference available. false 314 Investment in subsidiary 2 fe_InvestmentInConsolidatedSubsidiary fe false credit duration Investment In Consolidated Subsidiary. 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 250000000 250000 false false false 5 false false false false 0 0 false false false xbrli:monetaryItemType monetary Investment In Consolidated Subsidiary. No authoritative reference available. false 315 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 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 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 316 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 false false false 0 0   false false false 4 false true false false 250000000 250000 false false false 5 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 317 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 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 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 318 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 false false false 0 0   false false false 5 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 319 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 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 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 322 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 false 16 USD true false false false Consolidated [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_FirstEnergySolutionsCorpConsolidatedMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 17 USD true false false false Consolidated [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_FirstEnergySolutionsCorpConsolidatedMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 18 USD true false false false Consolidated [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_FirstEnergySolutionsCorpConsolidatedMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 19 USD true false false false Consolidated [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_FirstEnergySolutionsCorpConsolidatedMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ false 20 USD true false false false Consolidated [Member] dei_LegalEntityAxis xbrldi http://xbrl.org/2006/xbrldi fe_FirstEnergySolutionsCorpConsolidatedMember dei_LegalEntityAxis explicitMember USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 $ na No definition available. No authoritative reference available. false 323 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 xbrli:stringItemType string No definition available. false 324 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 1553677000 1553677 false false false 2 false true false false 1104572000 1104572 false false false 3 false true false false 4256444000 4256444 false false false 4 false true false false 3671830000 3671830 false false false 5 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 325 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 xbrli:stringItemType string No definition available. false 326 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 391087000 391087 false false false 2 false true false false 294693000 294693 false false false 3 false true false false 1061719000 1061719 false false false 4 false true false false 871160000 871160 false false false 5 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 327 Purchased power from affiliates 2 fe_CostOfPurchasedPowerFromAffiliates fe false debit duration Purchased power from affiliates. false false false false false false false false false false false verboselabel false 1 false true false false 116381000 116381 false false false 2 false true false false 35290000 35290 false false false 3 false true false false 246232000 246232 false false false 4 false true false false 149746000 149746 false false false 5 false false false false 0 0 false false false xbrli:monetaryItemType monetary Purchased power from affiliates. No authoritative reference available. false 328 Purchased power from non-affiliates 2 us-gaap_CostOfPurchasedPower us-gaap true debit duration No definition available. false false false false false false false false false false false terselabel false 1 false true false false 411084000 411084 false false false 2 false true false false 205200000 205200 false false false 3 false true false false 1160119000 1160119 false false false 4 false true false false 551155000 551155 false false false 5 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 329 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 309793000 309793 false false false 2 false true false false 305935000 305935 false false false 3 false true false false 916366000 916366 false false false 4 false true false false 891555000 891555 false false false 5 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 330 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 59298000 59298 false false false 2 false true false false 66041000 66041 false false false 3 false true false false 185535000 185535 false false false 4 false true false false 192962000 192962 false false false 5 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 331 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 verboselabel false 1 false true false false 21804000 21804 false false false 2 false true false false 21700000 21700 false false false 3 false true false false 70822000 70822 false false false 4 false true false false 66361000 66361 false false false 5 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. false 332 Impairment of long-lived assets 2 us-gaap_UtilitiesOperatingExpenseImpairments 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 291934000 291934 false false false 2 false false false false 0 0 false false false 3 false true false false 293767000 293767 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false xbrli:monetaryItemType monetary Discloses the amount of operating expense for the period related to impairments. No authoritative reference available. true 333 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 1601381000 1601381 false false false 2 false true false false 928859000 928859 false false false 3 false true false false 3934560000 3934560 false false false 4 false true false false 2722939000 2722939 false false false 5 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 334 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 -47704000 -47704 false false false 2 false true false false 175713000 175713 false false false 3 false true false false 321884000 321884 false false false 4 false true false false 948891000 948891 false false false 5 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 335 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 xbrli:stringItemType string Other Income Expense Abstract. false 336 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 29895000 29895 false false false 2 false true false false 158857000 158857 false false false 3 false true false false 43978000 43978 false false false 4 false true false false 135723000 135723 false false false 5 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 337 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 xbrli:stringItemType string Miscellaneous income expense Abstact. false 338 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 4765000 4765 false false false 2 false true false false 2804000 2804 false false false 3 false true false false 10468000 10468 false false false 4 false true false false 12840000 12840 false false false 5 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 339 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 -2497000 -2497 false false false 2 false true false false -2209000 -2209 false false false 3 false true false false -7362000 -7362 false false false 4 false true false false -8503000 -8503 false false false 5 false false false false 0 0 false false false xbrli:monetaryItemType monetary Interest expense to affiliates No authoritative reference available. false 340 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 -49544000 -49544 false false false 2 false true false false -42187000 -42187 false false false 3 false true false false -150560000 -150560 false false false 4 false true false false -90985000 -90985 false false false 5 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 341 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 22955000 22955 false false false 2 false true false false 17869000 17869 false false false 3 false true false false 66550000 66550 false false false 4 false true false false 41975000 41975 false false false 5 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 342 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 5574000 5574 false false false 2 false true false false 135134000 135134 false false false 3 false true false false -36926000 -36926 false false false 4 false true false false 91050000 91050 false false false 5 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 343 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 -42130000 -42130 false false false 2 false true false false 310847000 310847 false false false 3 false true false false 284958000 284958 false false false 4 false true false false 1039941000 1039941 false false false 5 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 344 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 -5404000 -5404 false false false 2 false true false false 111164000 111164 false false false 3 false true false false 107833000 107833 false false false 4 false true false false 372175000 372175 false false false 5 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 345 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 -36726000 -36726 false false false 2 false true false false 199683000 199683 false false false 3 false true false false 177125000 177125 false false false 4 false true false false 667766000 667766 false false false 5 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 346 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 xbrli:stringItemType string No definition available. false 347 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 10000 10 false false false 2 false true false false 266958000 266958 false false false 3 false true false false 10000 10 false false false 4 false true false false 266958000 266958 false false false 5 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 348 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 xbrli:stringItemType string No definition available. false 349 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 269986000 269986 false false false 2 false false false false 0 0 false false false 3 false true false false 269986000 269986 false false false 4 false false false false 0 0 false false false 5 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 350 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 325265000 325265 false false false 2 false false false false 0 0 false false false 3 false true false false 325265000 325265 false false false 4 false false false false 0 0 false false false 5 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 351 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 57407000 57407 false false false 2 false false false false 0 0 false false false 3 false true false false 57407000 57407 false false false 4 false false false false 0 0 false false false 5 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 352 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 501648000 501648 false false false 2 false false false false 0 0 false false false 3 false true false false 501648000 501648 false false false 4 false false false false 0 0 false false false 5 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 353 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 554043000 554043 false false false 2 false false false false 0 0 false false false 3 false true false false 554043000 554043 false false false 4 false false false false 0 0 false false false 5 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 354 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 204065000 204065 false false false 2 false false false false 0 0 false false false 3 false true false false 204065000 204065 false false false 4 false false false false 0 0 false false false 5 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 355 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 1912424000 1912424 false false false 2 false false false false 0 0 false false false 3 false true false false 1912424000 1912424 false false false 4 false false false false 0 0 false false false 5 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 356 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 xbrli:stringItemType string No definition available. false 357 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 9663264000 9663264 false false false 2 false false false false 0 0 false false false 3 false true false false 9663264000 9663264 false false false 4 false false false false 0 0 false false false 5 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 358 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 4114381000 4114381 false false false 2 false false false false 0 0 false false false 3 false true false false 4114381000 4114381 false false false 4 false false false false 0 0 false false false 5 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 359 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 5548883000 5548883 false false false 2 false false false false 0 0 false false false 3 false true false false 5548883000 5548883 false false false 4 false false false false 0 0 false false false 5 false true false false 5826474000 5826474 false false false xbrli:monetaryItemType monetary Net Plant Excluding Construction Work In Progress. No authoritative reference available. false 360 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 2736635000 2736635 false false false 2 false false false false 0 0 false false false 3 false true false false 2736635000 2736635 false false false 4 false false false false 0 0 false false false 5 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 361 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 8285518000 8285518 false false false 2 false false false false 0 0 false false false 3 false true false false 8285518000 8285518 false false false 4 false false false false 0 0 false false false 5 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 362 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 xbrli:stringItemType string No definition available. false 363 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 1158376000 1158376 false false false 2 false false false false 0 0 false false false 3 false true false false 1158376000 1158376 false false false 4 false false false false 0 0 false false false 5 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 364 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 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 xbrli:monetaryItemType monetary Investment in associated companies. No authoritative reference available. false 365 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 7400000 7400 false false false 2 false false false false 0 0 false false false 3 false true false false 7400000 7400 false false false 4 false false false false 0 0 false false false 5 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 366 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 1165776000 1165776 false false false 2 false false false false 0 0 false false false 3 false true false false 1165776000 1165776 false false false 4 false false false false 0 0 false false false 5 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 367 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 xbrli:stringItemType string Deferred Charges And Other Assets Abstract. false 368 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 3357000 3357 false false false 2 false false false false 0 0 false false false 3 false true false false 3357000 3357 false false false 4 false false false false 0 0 false false false 5 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 369 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 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 370 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 127420000 127420 false false false 2 false false false false 0 0 false false false 3 false true false false 127420000 127420 false false false 4 false false false false 0 0 false false false 5 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 371 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 true false false 50125000 50125 false false false xbrli:monetaryItemType monetary Property taxes. No authoritative reference available. false 372 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 61934000 61934 false false false 2 false false false false 0 0 false false false 3 false true false false 61934000 61934 false false false 4 false false false false 0 0 false false false 5 false true false false 72553000 72553 false false false xbrli:monetaryItemType monetary Unamortized sale and leaseback costs. No authoritative reference available. false 373 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 164332000 164332 false false false 2 false false false false 0 0 false false false 3 false true false false 164332000 164332 false false false 4 false false false false 0 0 false false false 5 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 374 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 431416000 431416 false false false 2 false false false false 0 0 false false false 3 false true false false 431416000 431416 false false false 4 false false false false 0 0 false false false 5 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 375 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 11795134000 11795134 false false false 2 false false false false 0 0 false false false 3 false true false false 11795134000 11795134 false false false 4 false false false false 0 0 false false false 5 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 376 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 xbrli:stringItemType string No definition available. false 377 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 1396792000 1396792 false false false 2 false false false false 0 0 false false false 3 false true false false 1396792000 1396792 false false false 4 false false false false 0 0 false false false 5 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 378 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 xbrli:stringItemType string No definition available. false 379 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 9642000 9642 false false false 2 false false false false 0 0 false false false 3 false true false false 9642000 9642 false false false 4 false false false false 0 0 false false false 5 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 380 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 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 381 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 xbrli:stringItemType string No definition available. false 382 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 472018000 472018 false false false 2 false false false false 0 0 false false false 3 false true false false 472018000 472018 false false false 4 false false false false 0 0 false false false 5 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 383 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 204928000 204928 false false false 2 false false false false 0 0 false false false 3 false true false false 204928000 204928 false false false 4 false false false false 0 0 false false false 5 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 384 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 59422000 59422 false false false 2 false false false false 0 0 false false false 3 false true false false 59422000 59422 false false false 4 false false false false 0 0 false false false 5 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 385 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 430824000 430824 false false false 2 false false false false 0 0 false false false 3 false true false false 430824000 430824 false false false 4 false false false false 0 0 false false false 5 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 386 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 2673626000 2673626 false false false 2 false false false false 0 0 false false false 3 false true false false 2673626000 2673626 false false false 4 false false false false 0 0 false false false 5 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 387 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 xbrli:stringItemType string No definition available. false 388 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 3730964000 3730964 false false false 2 false false false false 0 0 false false false 3 false true false false 3730964000 3730964 false false false 4 false false false false 0 0 false false false 5 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 389 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 2819150000 2819150 false false false 2 false false false false 0 0 false false false 3 false true false false 2819150000 2819150 false false false 4 false false false false 0 0 false false false 5 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 390 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 6550114000 6550114 false false false 2 false false false false 0 0 false false false 3 false true false false 6550114000 6550114 false false false 4 false false false false 0 0 false false false 5 false true false false 6226223000 6226223 false false false xbrli:monetaryItemType monetary Total Capitalization. No authoritative reference available. true 391 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 xbrli:stringItemType string No definition available. false 392 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 967583000 967583 false false false 2 false false false false 0 0 false false false 3 false true false false 967583000 967583 false false false 4 false false false false 0 0 false false false 5 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 393 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 false 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 394 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 55267000 55267 false false false 2 false false false false 0 0 false false false 3 false true false false 55267000 55267 false false false 4 false false false false 0 0 false false false 5 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 395 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 877522000 877522 false false false 2 false false false false 0 0 false false false 3 false true false false 877522000 877522 false false false 4 false false false false 0 0 false false false 5 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 396 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 228779000 228779 false false false 2 false false false false 0 0 false false false 3 false true false false 228779000 228779 false false false 4 false false false false 0 0 false false false 5 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 397 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 true false false 50125000 50125 false false false xbrli:monetaryItemType monetary Property taxes. No authoritative reference available. false 398 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 228119000 228119 false false false 2 false false false false 0 0 false false false 3 false true false false 228119000 228119 false false false 4 false false false false 0 0 false false false 5 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 399 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 163999000 163999 false false false 2 false false false false 0 0 false false false 3 false true false false 163999000 163999 false false false 4 false false false false 0 0 false false false 5 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 400 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 2571394000 2571394 false false false 2 false false false false 0 0 false false false 3 false true false false 2571394000 2571394 false false false 4 false false false false 0 0 false false false 5 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 401 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 11795134000 11795134 false false false 2 false false false false 0 0 false false false 3 false true false false 11795134000 11795134 false false false 4 false false false false 0 0 false false false 5 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 402 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 xbrli:stringItemType string No definition available. false 403 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 623927000 623927 false false false 4 false true false false 881811000 881811 false false false 5 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 404 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 xbrli:stringItemType string New Financing Abstract. false 405 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 249520000 249520 false false false 4 false true false false 2356762000 2356762 false false false 5 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 406 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 405000 405 false false false 4 false false false false 0 0   false false false 5 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 407 Equity contributions from parent 2 us-gaap_ProceedsFromContributionsFromParent 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 false false false 0 0   false false false 5 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash inflow from parent as a source of financing that is recorded as additional paid in capital. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 false 408 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 xbrli:stringItemType string Redemptions And Repayments Abstract. false 409 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 -296339000 -296339 false false false 4 false true false false -618213000 -618213 false false false 5 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 410 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 false false false 0 0 false false false 4 false true false false -1164823000 -1164823 false false false 5 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 411 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 -798000 -798 false false false 4 false true false false -20006000 -20006 false false false 5 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 412 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 -47212000 -47212 false false false 4 false true false false 553720000 553720 false false false 5 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 413 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 xbrli:stringItemType string No definition available. false 414 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 -801238000 -801238 false false false 4 false true false false -842600000 -842600 false false false 5 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 415 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 117213000 117213 false false false 4 false true false false 16129000 16129 false false false 5 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 416 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 1478086000 1478086 false false false 4 false true false false 2152717000 2152717 false false false 5 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 417 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 -1511273000 -1511273 false false false 4 false true false false -2175135000 -2175135 false false false 5 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 418 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 303455000 303455 false false false 4 false true false false -298841000 -298841 false false false 5 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 419 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 -110073000 -110073 false false false 4 false false false false 0 0 false false false 5 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 420 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 xbrli:monetaryItemType monetary Leasehold improvement payments to associated companies. No authoritative reference available. false 421 Investment in subsidiary 2 fe_InvestmentInConsolidatedSubsidiary fe false credit duration Investment In Consolidated Subsidiary. 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 false false false 0 0 false false false xbrli:monetaryItemType monetary Investment In Consolidated Subsidiary. No authoritative reference available. false 422 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 -1683000 -1683 false false false 4 false true false false -20882000 -20882 false false false 5 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 423 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 -576717000 -576717 false false false 4 false true false false -1168612000 -1168612 false false false 5 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 424 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 -2000 -2 false false false 4 false true false false 266919000 266919 false false false 5 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 425 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 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 426 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 10000 10 false false false 2 false true false false 266958000 266958 false false false 3 false true false false 10000 10 false false false 4 false true false false 266958000 266958 false false false 5 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 429 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 false 21 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 22 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 23 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 24 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 25 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 430 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 xbrli:stringItemType string No definition available. false 431 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 1540885000 1540885 false false false 2 false true false false 1087991000 1087991 false false false 3 false true false false 4203610000 4203610 false false false 4 false true false false 3357873000 3357873 false false false 5 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 432 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 xbrli:stringItemType string No definition available. false 433 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 13403000 13403 false false false 2 false true false false 9278000 9278 false false false 3 false true false false 25768000 25768 false false false 4 false true false false 16400000 16400 false false false 5 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 434 Purchased power from affiliates 2 fe_CostOfPurchasedPowerFromAffiliates fe false debit duration Purchased power from affiliates. false false false false false false false false false false false verboselabel false 1 false true false false 1058965000 1058965 false false false 2 false true false false 621996000 621996 false false false 3 false true false false 2940360000 2940360 false false false 4 false true false false 2351879000 2351879 false false false 5 false false false false 0 0 false false false xbrli:monetaryItemType monetary Purchased power from affiliates. No authoritative reference available. false 435 Purchased power from non-affiliates 2 us-gaap_CostOfPurchasedPower us-gaap true debit duration No definition available. false false false false false false false false false false false terselabel false 1 false true false false 411084000 411084 false false false 2 false true false false 205200000 205200 false false false 3 false true false false 1160119000 1160119 false false false 4 false true false false 551155000 551155 false false false 5 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 436 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 84169000 84169 false false false 2 false true false false 70246000 70246 false false false 3 false true false false 218278000 218278 false false false 4 false true false false 144284000 144284 false false false 5 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 437 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 752000 752 false false false 2 false true false false 1051000 1051 false false false 3 false true false false 2253000 2253 false false false 4 false true false false 3087000 3087 false false false 5 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 438 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 verboselabel false 1 false true false false 6216000 6216 false false false 2 false true false false 4351000 4351 false false false 3 false true false false 17432000 17432 false false false 4 false true false false 12826000 12826 false false false 5 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. false 439 Impairment of long-lived assets 2 us-gaap_UtilitiesOperatingExpenseImpairments 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 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 xbrli:monetaryItemType monetary Discloses the amount of operating expense for the period related to impairments. No authoritative reference available. true 440 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 1574589000 1574589 false false false 2 false true false false 912122000 912122 false false false 3 false true false false 4364210000 4364210 false false false 4 false true false false 3079631000 3079631 false false false 5 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 441 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 -33704000 -33704 false false false 2 false true false false 175869000 175869 false false false 3 false true false false -160600000 -160600 false false false 4 false true false false 278242000 278242 false false false 5 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 442 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 xbrli:stringItemType string Other Income Expense Abstract. false 443 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 256000 256 false false false 2 false true false false 35000 35 false false false 3 false true false false 3964000 3964 false false false 4 false true false false 83000 83 false false false 5 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 444 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 xbrli:stringItemType string Miscellaneous income expense Abstact. false 445 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 5707000 5707 false false false 2 false true false false 100668000 100668 false false false 3 false true false false 323371000 323371 false false false 4 false true false false 509927000 509927 false false false 5 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 446 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 -60000 -60 false false false 2 false true false false -35000 -35 false false false 3 false true false false -179000 -179 false false false 4 false true false false -103000 -103 false false false 5 false false false false 0 0 false false false xbrli:monetaryItemType monetary Interest expense to affiliates No authoritative reference available. false 447 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 -24158000 -24158 false false false 2 false true false false -15358000 -15358 false false false 3 false true false false -71793000 -71793 false false false 4 false true false false -20778000 -20778 false false false 5 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 448 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 95000 95 false false false 2 false true false false 49000 49 false false false 3 false true false false 293000 293 false false false 4 false true false false 146000 146 false false false 5 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 449 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 -18160000 -18160 false false false 2 false true false false 85359000 85359 false false false 3 false true false false 255656000 255656 false false false 4 false true false false 489275000 489275 false false false 5 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 450 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 -51864000 -51864 false false false 2 false true false false 261228000 261228 false false false 3 false true false false 95056000 95056 false false false 4 false true false false 767517000 767517 false false false 5 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 451 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 -15138000 -15138 false false false 2 false true false false 61545000 61545 false false false 3 false true false false -82069000 -82069 false false false 4 false true false false 99751000 99751 false false false 5 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 452 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 -36726000 -36726 false false false 2 false true false false 199683000 199683 false false false 3 false true false false 177125000 177125 false false false 4 false true false false 667766000 667766 false false false 5 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 453 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 xbrli:stringItemType string No definition available. false 454 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 266859000 266859 false false false 3 false false false false 0 0   false false false 4 false true false false 266859000 266859 false false false 5 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 455 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 xbrli:stringItemType string No definition available. false 456 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 299222000 299222 false false false 2 false false false false 0 0 false false false 3 false true false false 299222000 299222 false false false 4 false false false false 0 0 false false false 5 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 457 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 325265000 325265 false false false 2 false false false false 0 0 false false false 3 false true false false 325265000 325265 false false false 4 false false false false 0 0 false false false 5 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 458 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 34052000 34052 false false false 2 false false false false 0 0 false false false 3 false true false false 34052000 34052 false false false 4 false false false false 0 0 false false false 5 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 459 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 10100000 10100 false false false 2 false false false false 0 0 false false false 3 false true false false 10100000 10100 false false false 4 false false false false 0 0 false false false 5 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 460 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 28411000 28411 false false false 2 false false false false 0 0 false false false 3 false true false false 28411000 28411 false false false 4 false false false false 0 0 false false false 5 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 461 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 191423000 191423 false false false 2 false false false false 0 0 false false false 3 false true false false 191423000 191423 false false false 4 false false false false 0 0 false false false 5 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 462 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 888473000 888473 false false false 2 false false false false 0 0 false false false 3 false true false false 888473000 888473 false false false 4 false false false false 0 0 false false false 5 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 463 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 xbrli:stringItemType string No definition available. false 464 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 94787000 94787 false false false 2 false false false false 0 0 false false false 3 false true false false 94787000 94787 false false false 4 false false false false 0 0 false false false 5 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 465 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 16209000 16209 false false false 2 false false false false 0 0 false false false 3 false true false false 16209000 16209 false false false 4 false false false false 0 0 false false false 5 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 466 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 78578000 78578 false false false 2 false false false false 0 0 false false false 3 false true false false 78578000 78578 false false false 4 false false false false 0 0 false false false 5 false true false false 76825000 76825 false false false xbrli:monetaryItemType monetary Net Plant Excluding Construction Work In Progress. No authoritative reference available. false 467 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 7523000 7523 false false false 2 false false false false 0 0 false false false 3 false true false false 7523000 7523 false false false 4 false false false false 0 0 false false false 5 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 468 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 86101000 86101 false false false 2 false false false false 0 0 false false false 3 false true false false 86101000 86101 false false false 4 false false false false 0 0 false false false 5 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 469 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 xbrli:stringItemType string No definition available. false 470 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 false 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 471 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 4825221000 4825221 false false false 2 false false false false 0 0 false false false 3 false true false false 4825221000 4825221 false false false 4 false false false false 0 0 false false false 5 false true false false 4477602000 4477602 false false false xbrli:monetaryItemType monetary Investment in associated companies. No authoritative reference available. false 472 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 560000 560 false false false 2 false false false false 0 0 false false false 3 false true false false 560000 560 false false false 4 false false false false 0 0 false false false 5 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 473 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 4825781000 4825781 false false false 2 false false false false 0 0 false false false 3 false true false false 4825781000 4825781 false false false 4 false false false false 0 0 false false false 5 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 474 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 xbrli:stringItemType string Deferred Charges And Other Assets Abstract. false 475 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 71165000 71165 false false false 2 false false false false 0 0 false false false 3 false true false false 71165000 71165 false false false 4 false false false false 0 0 false false false 5 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 476 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 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 477 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 127420000 127420 false false false 2 false false false false 0 0 false false false 3 false true false false 127420000 127420 false false false 4 false false false false 0 0 false false false 5 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 478 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 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 xbrli:monetaryItemType monetary Property taxes. No authoritative reference available. false 479 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 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 xbrli:monetaryItemType monetary Unamortized sale and leaseback costs. No authoritative reference available. false 480 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 142039000 142039 false false false 2 false false false false 0 0 false false false 3 false true false false 142039000 142039 false false false 4 false false false false 0 0 false false false 5 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 481 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 364872000 364872 false false false 2 false false false false 0 0 false false false 3 false true false false 364872000 364872 false false false 4 false false false false 0 0 false false false 5 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 482 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 6165227000 6165227 false false false 2 false false false false 0 0 false false false 3 false true false false 6165227000 6165227 false false false 4 false false false false 0 0 false false false 5 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 483 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 xbrli:stringItemType string No definition available. false 484 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 765000 765 false false false 2 false false false false 0 0 false false false 3 false true false false 765000 765 false false false 4 false false false false 0 0 false false false 5 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 485 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 xbrli:stringItemType string No definition available. false 486 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 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 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 487 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 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 488 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 xbrli:stringItemType string No definition available. false 489 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 305726000 305726 false false false 2 false false false false 0 0 false false false 3 false true false false 305726000 305726 false false false 4 false false false false 0 0 false false false 5 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 490 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 95287000 95287 false false false 2 false false false false 0 0 false false false 3 false true false false 95287000 95287 false false false 4 false false false false 0 0 false false false 5 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 491 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 1821000 1821 false false false 2 false false false false 0 0 false false false 3 false true false false 1821000 1821 false false false 4 false false false false 0 0 false false false 5 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 492 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 253368000 253368 false false false 2 false false false false 0 0 false false false 3 false true false false 253368000 253368 false false false 4 false false false false 0 0 false false false 5 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 493 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 756967000 756967 false false false 2 false false false false 0 0 false false false 3 false true false false 756967000 756967 false false false 4 false false false false 0 0 false false false 5 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 494 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 xbrli:stringItemType string No definition available. false 495 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 3730964000 3730964 false false false 2 false false false false 0 0 false false false 3 false true false false 3730964000 3730964 false false false 4 false false false false 0 0 false false false 5 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 496 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 1518779000 1518779 false false false 2 false false false false 0 0 false false false 3 false true false false 1518779000 1518779 false false false 4 false false false false 0 0 false false false 5 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 497 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 5249743000 5249743 false false false 2 false false false false 0 0 false false false 3 false true false false 5249743000 5249743 false false false 4 false false false false 0 0 false false false 5 false true false false 5033910000 5033910 false false false xbrli:monetaryItemType monetary Total Capitalization. No authoritative reference available. true 498 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 xbrli:stringItemType string No definition available. false 499 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 false 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 500 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 false 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 501 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 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 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 502 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 false 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 503 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 36528000 36528 false false false 2 false false false false 0 0 false false false 3 false true false false 36528000 36528 false false false 4 false false false false 0 0 false false false 5 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 504 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 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 xbrli:monetaryItemType monetary Property taxes. No authoritative reference available. false 505 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 false 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 506 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 121989000 121989 false false false 2 false false false false 0 0 false false false 3 false true false false 121989000 121989 false false false 4 false false false false 0 0 false false false 5 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 507 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 158517000 158517 false false false 2 false false false false 0 0 false false false 3 false true false false 158517000 158517 false false false 4 false false false false 0 0 false false false 5 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 508 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 6165227000 6165227 false false false 2 false false false false 0 0 false false false 3 false true false false 6165227000 6165227 false false false 4 false false false false 0 0 false false false 5 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 509 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 xbrli:stringItemType string No definition available. false 510 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 -289503000 -289503 false false false 4 false true false false -37990000 -37990 false false false 5 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 511 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 xbrli:stringItemType string New Financing Abstract. false 512 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 1498087000 1498087 false false false 5 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 513 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 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 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 514 Equity contributions from parent 2 us-gaap_ProceedsFromContributionsFromParent 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 false false false 0 0   false false false 5 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash inflow from parent as a source of financing that is recorded as additional paid in capital. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 false 515 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 xbrli:stringItemType string Redemptions And Repayments Abstract. false 516 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 -599000 -599 false false false 4 false true false false -1507000 -1507 false false false 5 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 517 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 false false false 0 0 false false false 4 false true false false -901119000 -901119 false false false 5 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 518 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 -459000 -459 false false false 4 false true false false -11583000 -11583 false false false 5 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 519 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 -1058000 -1058 false false false 4 false true false false 583878000 583878 false false false 5 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 520 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 xbrli:stringItemType string No definition available. false 521 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 -5497000 -5497 false false false 4 false true false false -2224000 -2224 false false false 5 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 522 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 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 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 523 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 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 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 524 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 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 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 525 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 406304000 406304 false false false 4 false true false false -27054000 -27054 false false false 5 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 526 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 -110073000 -110073 false false false 4 false false false false 0 0 false false false 5 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 527 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 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 xbrli:monetaryItemType monetary Leasehold improvement payments to associated companies. No authoritative reference available. false 528 Investment in subsidiary 2 fe_InvestmentInConsolidatedSubsidiary fe false credit duration Investment In Consolidated Subsidiary. 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 -250000000 -250000 false false false 5 false false false false 0 0 false false false xbrli:monetaryItemType monetary Investment In Consolidated Subsidiary. No authoritative reference available. false 529 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 -173000 -173 false false false 4 false true false false 249000 249 false false false 5 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 530 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 290561000 290561 false false false 4 false true false false -279029000 -279029 false false false 5 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 531 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 false false false 0 0   false false false 4 false true false false 266859000 266859 false false false 5 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 532 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 false false false 0 0   false false false 5 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 533 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 266859000 266859 false false false 3 false false false false 0 0   false false false 4 false true false false 266859000 266859 false false false 5 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 536 Percent [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 false 26 true false false false Percent [Member] fe_SubsequentEventsMeasurementUnitsAxis xbrldi http://xbrl.org/2006/xbrldi fe_PercentMember fe_SubsequentEventsMeasurementUnitsAxis explicitMember Pure Standard http://www.xbrl.org/2003/instance pure xbrli 0 na No definition available. No authoritative reference available. false 641 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 xbrli:stringItemType string Supplemental Guarantor Information. false 642 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 true false false 0.93825 0.93825 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 us-types:percentItemType pure Sale and leaseback transactions of undivided interest. No authoritative reference available. false 643 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 false 27 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 28 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 29 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 30 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 31 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 644 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 xbrli:stringItemType string No definition available. false 645 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 645001000 645001 false false false 2 false true false false 477679000 477679 false false false 3 false true false false 1793986000 1793986 false false false 4 false true false false 1726715000 1726715 false false false 5 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 646 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 xbrli:stringItemType string No definition available. false 647 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 329009000 329009 false false false 2 false true false false 241953000 241953 false false false 3 false true false false 910739000 910739 false false false 4 false true false false 755632000 755632 false false false 5 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 648 Purchased power from affiliates 2 fe_CostOfPurchasedPowerFromAffiliates fe false debit duration Purchased power from affiliates. false false false false false false false false false false false verboselabel false 1 false true false false 13404000 13404 false false false 2 false true false false 9233000 9233 false false false 3 false true false false 25646000 25646 false false false 4 false true false false 16333000 16333 false false false 5 false false false false 0 0 false false false xbrli:monetaryItemType monetary Purchased power from affiliates. 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No authoritative reference available. false 650 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 97322000 97322 false false false 2 false true false false 109828000 109828 false false false 3 false true false false 289638000 289638 false false false 4 false true false false 313416000 313416 false false false 5 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 651 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 23845000 23845 false false false 2 false true false false 30469000 30469 false false false 3 false true false false 77838000 77838 false false false 4 false true false false 90680000 90680 false false false 5 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 652 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 verboselabel false 1 false true false false 8875000 8875 false false false 2 false true false false 11331000 11331 false false false 3 false true false false 32702000 32702 false false false 4 false true false false 35289000 35289 false false false 5 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. false 653 Impairment of long-lived assets 2 us-gaap_UtilitiesOperatingExpenseImpairments 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 291934000 291934 false false false 2 false false false false 0 0 false false false 3 false true false false 293767000 293767 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false xbrli:monetaryItemType monetary Discloses the amount of operating expense for the period related to impairments. 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No authoritative reference available. true 656 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 xbrli:stringItemType string Other Income Expense Abstract. false 657 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 396000 396 false false false 2 false true false false 319000 319 false false false 3 false true false false 531000 531 false false false 4 false true false false 758000 758 false false false 5 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 658 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 xbrli:stringItemType string Miscellaneous income expense Abstact. false 659 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 2562000 2562 false false false 2 false true false false 744000 744 false false false 3 false true false false 1638000 1638 false false false 4 false true false false 1209000 1209 false false false 5 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 660 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 -2021000 -2021 false false false 2 false true false false -1267000 -1267 false false false 3 false true false false -5917000 -5917 false false false 4 false true false false -4648000 -4648 false false false 5 false false false false 0 0 false false false xbrli:monetaryItemType monetary Interest expense to affiliates No authoritative reference available. false 661 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 -26243000 -26243 false false false 2 false true false false -26737000 -26737 false false false 3 false true false false -80548000 -80548 false false false 4 false true false false -72762000 -72762 false false false 5 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. 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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 663 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 -6282000 -6282 false false false 2 false true false false -11560000 -11560 false false false 3 false true false false -29366000 -29366 false false false 4 false true false false -41186000 -41186 false false false 5 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 664 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 -125670000 -125670 false false false 2 false true false false 63305000 63305 false false false 3 false true false false 134290000 134290 false false false 4 false true false false 474179000 474179 false false false 5 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 665 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 -44364000 -44364 false false false 2 false true false false 19646000 19646 false false false 3 false true false false 52144000 52144 false false false 4 false true false false 166902000 166902 false false false 5 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 666 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 -81306000 -81306 false false false 2 false true false false 43659000 43659 false false false 3 false true false false 82146000 82146 false false false 4 false true false false 307277000 307277 false false false 5 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 667 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 xbrli:stringItemType string No definition available. false 668 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 1000 1 false false false 2 false true false false 99000 99 false false false 3 false true false false 1000 1 false false false 4 false true false false 99000 99 false false false 5 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 669 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 xbrli:stringItemType string No definition available. false 670 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 193951000 193951 false false false 2 false false false false 0 0 false false false 3 false true false false 193951000 193951 false false false 4 false false false false 0 0 false false false 5 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 671 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 false 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 672 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 4831000 4831 false false false 2 false false false false 0 0 false false false 3 false true false false 4831000 4831 false false false 4 false false false false 0 0 false false false 5 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 673 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 329461000 329461 false false false 2 false false false false 0 0 false false false 3 false true false false 329461000 329461 false false false 4 false false false false 0 0 false false false 5 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 674 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 301761000 301761 false false false 2 false false false false 0 0 false false false 3 false true false false 301761000 301761 false false false 4 false false false false 0 0 false false false 5 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 675 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 9669000 9669 false false false 2 false false false false 0 0 false false false 3 false true false false 9669000 9669 false false false 4 false false false false 0 0 false false false 5 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 676 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 839674000 839674 false false false 2 false false false false 0 0 false false false 3 false true false false 839674000 839674 false false false 4 false false false false 0 0 false false false 5 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 677 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 xbrli:stringItemType string No definition available. false 678 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 4640027000 4640027 false false false 2 false false false false 0 0 false false false 3 false true false false 4640027000 4640027 false false false 4 false false false false 0 0 false false false 5 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 679 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 2173661000 2173661 false false false 2 false false false false 0 0 false false false 3 false true false false 2173661000 2173661 false false false 4 false false false false 0 0 false false false 5 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 680 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 2466366000 2466366 false false false 2 false false false false 0 0 false false false 3 false true false false 2466366000 2466366 false false false 4 false false false false 0 0 false false false 5 false true false false 2700026000 2700026 false false false xbrli:monetaryItemType monetary Net Plant Excluding Construction Work In Progress. No authoritative reference available. false 681 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 2221270000 2221270 false false false 2 false false false false 0 0 false false false 3 false true false false 2221270000 2221270 false false false 4 false false false false 0 0 false false false 5 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 682 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 4687636000 4687636 false false false 2 false false false false 0 0 false false false 3 false true false false 4687636000 4687636 false false false 4 false false false false 0 0 false false false 5 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 683 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 xbrli:stringItemType string No definition available. false 684 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 false 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 685 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 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 xbrli:monetaryItemType monetary Investment in associated companies. No authoritative reference available. false 686 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 6639000 6639 false false false 2 false false false false 0 0 false false false 3 false true false false 6639000 6639 false false false 4 false false false false 0 0 false false false 5 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 687 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 6639000 6639 false false false 2 false false false false 0 0 false false false 3 false true false false 6639000 6639 false false false 4 false false false false 0 0 false false false 5 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 688 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 xbrli:stringItemType string Deferred Charges And Other Assets Abstract. false 689 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 402397000 402397 false false false 2 false false false false 0 0 false false false 3 false true false false 402397000 402397 false false false 4 false false false false 0 0 false false false 5 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 690 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 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 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 691 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 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 692 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 true false false 27811000 27811 false false false xbrli:monetaryItemType monetary Property taxes. No authoritative reference available. false 693 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 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 16454000 16454 false false false xbrli:monetaryItemType monetary Unamortized sale and leaseback costs. No authoritative reference available. false 694 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 75033000 75033 false false false 2 false false false false 0 0 false false false 3 false true false false 75033000 75033 false false false 4 false false false false 0 0 false false false 5 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 695 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 505241000 505241 false false false 2 false false false false 0 0 false false false 3 false true false false 505241000 505241 false false false 4 false false false false 0 0 false false false 5 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 696 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 6039190000 6039190 false false false 2 false false false false 0 0 false false false 3 false true false false 6039190000 6039190 false false false 4 false false false false 0 0 false false false 5 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 697 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 xbrli:stringItemType string No definition available. false 698 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 487357000 487357 false false false 2 false false false false 0 0 false false false 3 false true false false 487357000 487357 false false false 4 false false false false 0 0 false false false 5 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 699 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 xbrli:stringItemType string No definition available. false 700 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 9642000 9642 false false false 2 false false false false 0 0 false false false 3 false true false false 9642000 9642 false false false 4 false false false false 0 0 false false false 5 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 701 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 false 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 702 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 xbrli:stringItemType string No definition available. false 703 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 244383000 244383 false false false 2 false false false false 0 0 false false false 3 false true false false 244383000 244383 false false false 4 false false false false 0 0 false false false 5 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 704 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 109641000 109641 false false false 2 false false false false 0 0 false false false 3 false true false false 109641000 109641 false false false 4 false false false false 0 0 false false false 5 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 705 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 46889000 46889 false false false 2 false false false false 0 0 false false false 3 false true false false 46889000 46889 false false false 4 false false false false 0 0 false false false 5 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 706 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 110964000 110964 false false false 2 false false false false 0 0 false false false 3 false true false false 110964000 110964 false false false 4 false false false false 0 0 false false false 5 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 707 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 1008876000 1008876 false false false 2 false false false false 0 0 false false false 3 false true false false 1008876000 1008876 false false false 4 false false false false 0 0 false false false 5 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 708 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 xbrli:stringItemType string No definition available. false 709 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 2443222000 2443222 false false false 2 false false false false 0 0 false false false 3 false true false false 2443222000 2443222 false false false 4 false false false false 0 0 false false false 5 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 710 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 2053532000 2053532 false false false 2 false false false false 0 0 false false false 3 false true false false 2053532000 2053532 false false false 4 false false false false 0 0 false false false 5 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 711 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 4496754000 4496754 false false false 2 false false false false 0 0 false false false 3 false true false false 4496754000 4496754 false false false 4 false false false false 0 0 false false false 5 false true false false 4253333000 4253333 false false false xbrli:monetaryItemType monetary Total Capitalization. No authoritative reference available. true 712 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 xbrli:stringItemType string No definition available. false 713 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 false 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 714 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 false 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 715 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 34050000 34050 false false false 2 false false false false 0 0 false false false 3 false true false false 34050000 34050 false false false 4 false false false false 0 0 false false false 5 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 716 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 26395000 26395 false false false 2 false false false false 0 0 false false false 3 false true false false 26395000 26395 false false false 4 false false false false 0 0 false false false 5 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 717 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 192251000 192251 false false false 2 false false false false 0 0 false false false 3 false true false false 192251000 192251 false false false 4 false false false false 0 0 false false false 5 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 718 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 true false false 27811000 27811 false false false xbrli:monetaryItemType monetary Property taxes. No authoritative reference available. false 719 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 228119000 228119 false false false 2 false false false false 0 0 false false false 3 false true false false 228119000 228119 false false false 4 false false false false 0 0 false false false 5 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 720 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 24934000 24934 false false false 2 false false false false 0 0 false false false 3 false true false false 24934000 24934 false false false 4 false false false false 0 0 false false false 5 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 721 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 533560000 533560 false false false 2 false false false false 0 0 false false false 3 false true false false 533560000 533560 false false false 4 false false false false 0 0 false false false 5 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 722 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 6039190000 6039190 false false false 2 false false false false 0 0 false false false 3 false true false false 6039190000 6039190 false false false 4 false false false false 0 0 false false false 5 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 723 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 xbrli:stringItemType string No definition available. false 724 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 402332000 402332 false false false 4 false true false false 520169000 520169 false false false 5 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 725 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 xbrli:stringItemType string New Financing Abstract. false 726 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 249520000 249520 false false false 4 false true false false 524710000 524710 false false false 5 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 727 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 405000 405 false false false 4 false false false false 0 0   false false false 5 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 728 Equity contributions from parent 2 us-gaap_ProceedsFromContributionsFromParent 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 100000000 100000 false false false 5 false false false false 0 0 false false false xbrli:monetaryItemType monetary The cash inflow from parent as a source of financing that is recorded as additional paid in capital. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 false 729 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 xbrli:stringItemType string Redemptions And Repayments Abstract. false 730 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 -261965000 -261965 false false false 4 false true false false -258583000 -258583 false false false 5 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 731 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 false false false 0 0 false false false 4 false true false false -257357000 -257357 false false false 5 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 732 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 -237000 -237 false false false 4 false true false false -5261000 -5261 false false false 5 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 733 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 -12277000 -12277 false false false 4 false true false false 103509000 103509 false false false 5 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 734 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 xbrli:stringItemType string No definition available. false 735 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 -417146000 -417146 false false false 4 false true false false -439531000 -439531 false false false 5 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 736 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 117213000 117213 false false false 4 false true false false 16129000 16129 false false false 5 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 737 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 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 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 738 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 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 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 739 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 -88625000 -88625 false false false 4 false true false false -178746000 -178746 false false false 5 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 740 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 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 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 741 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 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 xbrli:monetaryItemType monetary Leasehold improvement payments to associated companies. No authoritative reference available. false 742 Investment in subsidiary 2 fe_InvestmentInConsolidatedSubsidiary fe false credit duration Investment In Consolidated Subsidiary. 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 false false false 0 0 false false false xbrli:monetaryItemType monetary Investment In Consolidated Subsidiary. No authoritative reference available. false 743 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 -1499000 -1499 false false false 4 false true false false -21470000 -21470 false false false 5 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 744 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 -390057000 -390057 false false false 4 false true false false -623618000 -623618 false false false 5 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 745 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 -2000 -2 false false false 4 false true false false 60000 60 false false false 5 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 746 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 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 747 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 1000 1 false false false 2 false true false false 99000 99 false false false 3 false true false false 1000 1 false false false 4 false true false false 99000 99 false false false 5 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 750 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 false 32 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 33 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 763 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 xbrli:stringItemType string Other Income Expense Abstract. false 764 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 true true false false 56000000 56000 false false false 4 true true false false 47000000 47000 false false false 5 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 1 * Includes excise tax collections of $120 million and $106 million in the three months ended September 30, 2010 and 2009, respectively, and $328 million and $310 million in the nine months ended September 30, 2010 and 2009, respectively 5 616 false Thousands UnKnown UnKnown false true