Fair Value Measurements (Details 2) (USD $) In Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 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	$ 1,974	$ 662	$ 3,678	$ 2,577
Realized gains	98	49	220	132
Realized losses	(38)	(32)	(83)	(118)
Investment income	20	19	72	56
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	1,100	521	1,613	1,478
Realized gains	52	47	74	101
Realized losses	(19)	(30)	(42)	(88)
Investment income	9	11	41	33
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	134	19	154	79
Realized gains	7	0	7	2
Realized losses	(1)	0	(1)	0
Investment income	1	1	3	2
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	51	12	80	118
Realized gains	4	0	5	3
Realized losses	(2)	(1)	(4)	(1)
Investment income	0	0	2	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	234	59	610	340
Realized gains	11	1	37	10
Realized losses	(4)	(1)	(10)	(10)
Investment income	5	4	13	10
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	306	44	807	420
Realized gains	15	1	63	10
Realized losses	(8)	0	(15)	(12)
Investment income	3	2	8	5
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	149	7	414	141
Realized gains	9	0	34	6
Realized losses	(4)	0	(11)	(7)
Investment income	$ 2	$ 1	$ 5	$ 5