Consolidated Statements of Comprehensive Income (FirstEnergy Corp.) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Statement of Comprehensive Income [Abstract]
NET INCOME	$ 208	$ 196
OTHER COMPREHENSIVE INCOME (LOSS):
Pension and OPEB prior service costs	(42)	(46)
Amortized losses on derivative hedges	0	1
Change in unrealized gain on available-for-sale securities	21	5
Other comprehensive income (loss)	(21)	(40)
Income tax benefits on other comprehensive loss	(8)	(16)
Net other comprehensive income (loss)	(13)	(24)
COMPREHENSIVE INCOME (LOSS)	$ 195	$ 172