DISCONTINUED OPERATIONS - Major Classes of Cash Flow Items from Discontinued Operations (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Income from discontinued operations	[1]	$ 44	$ 76	$ 8
Gain on disposal, net of tax		(47)	(76)	(59)
Deferred income taxes and investment tax credits, net		297	113	252
FES and FENOC | Discontinued Operations, Disposed of by Means Other than Sale
CASH FLOWS FROM OPERATING ACTIVITIES:
Income from discontinued operations		44	76	8
Gain on disposal, net of tax		(47)	(76)	(59)
Deferred income taxes and investment tax credits, net		$ 0	$ 0	$ 47

[1] Net of income tax benefit of $48 million, $59 million, and $5 million in 2021, 2020 and 2019, respectively.