Discontinued Operations - Gain on Deconsolidation (Details) - FES and FENOC - Discontinued Operations, Disposed of by Means Other than Sale - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Removal of investment in FES and FENOC	$ 2,193
Assumption of benefit obligations retained at FE (including Pension, OPEB and EDCP)	(820)
Guarantees and credit support provided by FE	(139)
Reserve on receivables and allocated Pension/OPEB mark-to-market	(914)
Gain on deconsolidation of FES and FENOC, before tax	320
Income tax benefit including estimated worthless stock deduction	919
Gain on deconsolidation of FES and FENOC	$ 1,239	$ 0

Deconsolidation, Assumption of Define Benefit Obligations Retained

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- Definition

Deconsolidation, Gain (Loss), Amount, Before Tax

+ References

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+ References

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- Definition

The amount of the gain (loss) recognized by the parent and included in its attributable portion of net income for the period due to deconsolidation of a subsidiary or derecognition of a group of assets. The gain (loss) recognized and included in the net income attributable to the parent for the period is generally computed as the difference between: (a) the aggregate of: (1) the fair value of any consideration received; (2) the fair value of any retained noncontrolling investment in the former subsidiary at the date the subsidiary was deconsolidated; and (3) the carrying amount of any noncontrolling interest in the former subsidiary (including any accumulated other comprehensive income attributable to the noncontrolling interest) at the date the subsidiary was deconsolidated and (b) the carrying amount of the former subsidiary's assets and liabilities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 1B
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=84161450&loc=SL4582445-111684

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In connection with deconsolidation of a subsidiary or derecognition of a group of assets, the portion of any gain (loss) recognized by the parent, during the period, which is related to the remeasurement of any retained investment in the former subsidiary or group of assets to its fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 1B
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84161450&loc=SL4582445-111684

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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