Consolidated Statements of Comprehensive Income (Unaudited) (FirstEnergy Corp.) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Statement of Income and Comprehensive Income [Abstract]
NET INCOME	$ 188	$ 193	$ 494	$ 240
OTHER COMPREHENSIVE INCOME (LOSS):
Pension and OPEB prior service costs	(48)	48	(101)	4
Amortized gain (loss) on derivative hedges	3	17	1	11
Change in unrealized gain on available-for-sale securities	2	10	12	19
Other comprehensive income (loss)	(43)	75	(88)	34
Income taxes (benefits) on other comprehensive income (loss)	(27)	33	(51)	14
Other comprehensive income (loss), net of tax	(16)	42	(37)	20
COMPREHENSIVE INCOME	172	235	457	260
Comprehensive income (loss) attributable to noncontrolling interest	1	(10)	1	(15)
COMPREHENSIVE INCOME AVAILABLE TO FIRSTENERGY CORP.	$ 171	$ 245	$ 456	$ 275