Fair Value Measurements (Details 2) (USD $) In Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 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	$ 734	$ 1,183	$ 1,703	$ 1,915
Realized gains	22	46	122	83
Realized losses	(16)	(36)	(45)	(86)
Investment income	28	16	52	37
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	297	685	513	957
Realized gains	10	41	22	54
Realized losses	(7)	(35)	(23)	(58)
Investment income	17	9	32	22
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	12	57	20	60
Realized gains		2		2
Investment income	1		2	1
TE
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	15	76	28	107
Realized gains	1	2	1	3
Realized losses	(1)		(2)
Investment income	1		1	1
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	159	91	376	281
Realized gains	4		26	9
Realized losses	(2)		(6)	(9)
Investment income	4	3	8	7
Met-Ed
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	165	233	501	377
Realized gains	4	1	48	9
Realized losses	(3)	(1)	(7)	(12)
Investment income	3	2	5	3
Penelec
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	86	41	265	134
Realized gains	3		25	6
Realized losses	(3)		(7)	(7)
Investment income	$ 2	$ 2	$ 4	$ 3