Fair Value Measurements (Details 4) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
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	$ 131	$ 734	$ 382	$ 1,703
Realized gains	17	22	37	122
Realized losses	(18)	(16)	(35)	(45)
Interest and dividend income	18	28	33	52
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	25	297	109	513
Realized gains	13	10	26	22
Realized losses	(14)	(7)	(25)	(23)
Interest and dividend income	11	17	18	32
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	20	12	57	20
Realized gains	0	0	0	0
Realized losses	0	0	0	0
Interest and dividend income	1	1	1	2
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	70	159	165	376
Realized gains	1	4	2	26
Realized losses	(1)	(2)	(2)	(6)
Interest and dividend income	$ 3	$ 4	$ 7	$ 8