DISCONTINUED OPERATIONS - Major Classes of Cash Flow Items from Discontinued Operations (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
CASH FLOWS FROM OPERATING ACTIVITIES:
Income (loss) from discontinued operations	[1]	$ (21)	$ 0	$ 44
Disposal group not discontinued operation gain loss on disposal statement of income extensible list not disclosed flag		Loss (gain) on disposal, net of tax	Loss (gain) on disposal, net of tax	Loss (gain) on disposal, net of tax
FES and FENOC | Discontinued Operations, Disposed of by Means Other than Sale
CASH FLOWS FROM OPERATING ACTIVITIES:
Income (loss) from discontinued operations		$ (21)	$ 0	$ 44
Loss (gain) on disposal, net of tax		$ 21	$ 0	$ (47)

[1] Net of income tax benefit (expense) of ($21 million) and $48 million in 2023 and 2021, respectively.