Discontinued Operations - Major Classes of Cash Flow Items from Discontinued Operations (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
CASH FLOWS FROM OPERATING ACTIVITIES:
Income (loss) from discontinued operations	$ 326	$ (1,435)	$ (6,728)
Gain on disposal, net of tax (Note 3)	(435)	0	0
Depreciation and amortization, including nuclear fuel, regulatory assets, net, intangible assets and deferred debt-related costs	1,384	1,700	1,974
Deferred income taxes and investment tax credits, net	485	839	(3,063)
Unrealized (gain) loss on derivative transactions	(5)	81	9
CASH FLOWS FROM INVESTING ACTIVITIES:
Property additions	(2,675)	(2,587)	(2,835)
Nuclear fuel	0	(254)	(232)
Sales of investment securities held in trusts	909	2,170	1,678
Purchases of investment securities held in trusts	(963)	(2,268)	(1,789)
FES and FENOC \| Discontinued Operations, Disposed of by Means Other than Sale
CASH FLOWS FROM OPERATING ACTIVITIES:
Income (loss) from discontinued operations	326	(1,435)	(6,728)
Gain on disposal, net of tax (Note 3)	435	0	0
Depreciation and amortization, including nuclear fuel, regulatory assets, net, intangible assets and deferred debt-related costs	110	333	669
Deferred income taxes and investment tax credits, net	61	(842)	(3,582)
Unrealized (gain) loss on derivative transactions	(10)	81	9
CASH FLOWS FROM INVESTING ACTIVITIES:
Property additions	(27)	(317)	(615)
Nuclear fuel	0	(254)	(232)
Sales of investment securities held in trusts	109	940	717
Purchases of investment securities held in trusts	$ (122)	$ (999)	$ (783)

Amount of deferred income tax expense (benefit) and income tax credits.

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