Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Statement of Comprehensive Income [Abstract]
NET INCOME	$ 420	$ 344	$ 984	$ 824
OTHER COMPREHENSIVE INCOME (LOSS):
Pension and OPEB prior service costs	(2)	(2)	(5)	(6)
Amortized losses on derivative hedges	0	0	2	8
Other comprehensive income (loss)	(2)	(2)	(3)	2
Income tax benefits on other comprehensive income (loss)	(1)	(1)	(1)	0
Other comprehensive income (loss), net of tax	(1)	(1)	(2)	2
COMPREHENSIVE INCOME	419	343	982	826
Comprehensive income attributable to noncontrolling interest	20	10	57	15
COMPREHENSIVE INCOME ATTRIBUTABLE TO FIRSTENERGY CORP.	$ 399	$ 333	$ 925	$ 811