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Such securities are reported at fair value, with unrealized gains and losses excluded from earnings and reported in a separate component of shareholders' equity (other comprehensive income), unless the Available-for-sale Security is designated as a hedge or is determined to have had an other than temporary decline in fair value below its amortized cost basis. All or a portion of the unrealized holding gain or loss of an Available-for-sale Security that is designated as being hedged in a fair value hedge shall be recognized in earnings during the period of the hedge, as should other than temporary declines in fair value below costs basis. 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Such item represents the gross unrecognized holding gain. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 19 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 115 -Paragraph 137 false 1962 Unrealized Losses 2 us-gaap_HeldToMaturitySecuritiesUnrecognizedHoldingLosses us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false true false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 0 0 false false false xbrli:monetaryItemType monetary As of the balance sheet date, the excess of carrying value (amortized cost) over fair value of a debt security categorized as held-to-maturity, exclusive of dividend or interest income recognized but not yet received and exclusive of any write-downs for other-than-temporary impairment. 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Such gross unrealized gains are the excess of the fair value of the Available-for-sale Securities over their carrying value as of the reporting date. Such gross unrealized gains are included in other comprehensive income in the statement of shareholders' equity, unless the Available-for-sale Security is designated as a hedge. All or a portion of the unrealized holding gain of an available-for-sale security that is designated as being hedged in a fair value hedge shall be recognized in earnings during the period of the hedge. 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No authoritative reference available. false 5474 Fair value and related carrying amounts of long-term debt and other long-term obligations 2 fe_FairValueAndRelatedCarryingAmountsOfLongTermDebtAndOtherLongTermObligationsAbstract fe false na duration Fair value and related carrying amounts of long-term debt and other long-term obligations. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string Fair value and related carrying amounts of long-term debt and other long-term obligations. false 5475 long-term debt and other long-term obligations 2 fe_LongTermDebtAndOtherLongTermObligations fe false credit instant long-term debt and other long-term obligations. false false false false false false false false false false false verboselabel false 1 false true false false 14992000000 14992000000 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 14502000000 14502000000 false false false xbrli:monetaryItemType monetary long-term debt and other long-term obligations. 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No authoritative reference available. false 5510 Fair value and related carrying amounts of long-term debt and other long-term obligations 2 fe_FairValueAndRelatedCarryingAmountsOfLongTermDebtAndOtherLongTermObligationsAbstract fe false na duration Fair value and related carrying amounts of long-term debt and other long-term obligations. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string Fair value and related carrying amounts of long-term debt and other long-term obligations. false 5511 long-term debt and other long-term obligations 2 fe_LongTermDebtAndOtherLongTermObligations fe false credit instant long-term debt and other long-term obligations. false false false false false false false false false false false verboselabel false 1 false true false false 4386000000 4386000000 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 4306000000 4306000000 false false false xbrli:monetaryItemType monetary long-term debt and other long-term obligations. 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Such amount may include accrued interest receivable in accordance with the terms of the note. The note also may contain provisions and related items including a discount or premium, payable on demand, secured, or unsecured, interest bearing or noninterest bearing, among myriad other features and characteristics. 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No authoritative reference available. false 5546 Fair value and related carrying amounts of long-term debt and other long-term obligations 2 fe_FairValueAndRelatedCarryingAmountsOfLongTermDebtAndOtherLongTermObligationsAbstract fe false na duration Fair value and related carrying amounts of long-term debt and other long-term obligations. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string Fair value and related carrying amounts of long-term debt and other long-term obligations. false 5547 long-term debt and other long-term obligations 2 fe_LongTermDebtAndOtherLongTermObligations fe false credit instant long-term debt and other long-term obligations. false false false false false false false false false false false verboselabel false 1 false true false false 2110000000 2110000000 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 2032000000 2032000000 false false false xbrli:monetaryItemType monetary long-term debt and other long-term obligations. 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No authoritative reference available. false 5582 Fair value and related carrying amounts of long-term debt and other long-term obligations 2 fe_FairValueAndRelatedCarryingAmountsOfLongTermDebtAndOtherLongTermObligationsAbstract fe false na duration Fair value and related carrying amounts of long-term debt and other long-term obligations. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false false false false 0 0 false false false xbrli:stringItemType string Fair value and related carrying amounts of long-term debt and other long-term obligations. false 5583 long-term debt and other long-term obligations 2 fe_LongTermDebtAndOtherLongTermObligations fe false credit instant long-term debt and other long-term obligations. false false false false false false false false false false false verboselabel false 1 false true false false 682000000 682000000 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false 5 false false false false 0 0 false false false 6 false true false false 638000000 638000000 false false false xbrli:monetaryItemType monetary long-term debt and other long-term obligations. 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