Fair Value Measurements (Details 4) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Proceeds from the sale of investments in available-for-sale securities, realized gains and losses on those sales, and interest and dividend income
Sales Proceeds	$ 2,980	$ 4,207	$ 3,172
Realized gains	179	229	126
Realized losses	(99)	(90)	(107)
Interest and dividend income	70	82	79
FES
Proceeds from the sale of investments in available-for-sale securities, realized gains and losses on those sales, and interest and dividend income
Sales Proceeds	1,464	1,843	1,927
Realized gains	124	80	92
Realized losses	(73)	(46)	(75)
Interest and dividend income	39	47	47
OE
Proceeds from the sale of investments in available-for-sale securities, realized gains and losses on those sales, and interest and dividend income
Sales Proceeds	105	154	83
Realized gains	0	6	2
Realized losses	0	0	0
Interest and dividend income	3	3	3
JCP&L
Proceeds from the sale of investments in available-for-sale securities, realized gains and losses on those sales, and interest and dividend income
Sales Proceeds	516	779	411
Realized gains	12	39	10
Realized losses	(5)	(11)	(10)
Interest and dividend income	$ 14	$ 15	$ 14