EARNINGS PER SHARE - Schedule of Reconciles Basic and Diluted Eps Attributable to FE (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Earnings Per Share [Abstract]
Earnings attributable to FE - continuing operations		$ 419	$ 421	$ 717	$ 948
Earnings attributable to FE - discontinued operations, net of tax	[1]	0	(21)	0	(21)
Earnings attributable to FE		$ 419	$ 400	$ 717	$ 927
Share count information:
Weighted average number of basic shares outstanding (in shares)		576	573	575	573
Assumed exercise of dilutive awards (in shares)		1	1	1	1
Weighted average number of diluted shares outstanding (in shares)		577	574	576	574
EPS attributable to FE:
Basic - continuing operations (in dollars per share)		$ 0.73	$ 0.74	$ 1.25	$ 1.66
Basic - discontinued operations (in dollars per share)		0	(0.04)	0	(0.04)
Basic EPS (in dollars per share)		0.73	0.70	1.25	1.62
Diluted - continuing operations (in dollars per share)		0.73	0.73	1.24	1.65
Diluted - discontinued operations (in dollars per share)		0	(0.04)	0	(0.04)
Diluted EPS (in dollars per share)		$ 0.73	$ 0.69	$ 1.24	$ 1.61

[1] Consists of income taxes of $21 million during the three and nine months ended September 30, 2023.