Fair Value Measurements (Details 3) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Debt Securities
Amortized cost basis, unrealized gains and losses and fair values of investments in available-for-sale securities
Cost Basis	$ 1,827	[1]	$ 1,980	[2]
Unrealized Gains	34	[1]	25	[2]
Fair Value	1,861	[1]	2,005	[2]
Equity securities
Amortized cost basis, unrealized gains and losses and fair values of investments in available-for-sale securities
Cost Basis	293	[1]	222	[2]
Unrealized Gains	16	[1]	36	[2]
Fair Value	309	[1]	258	[2]
FES | Debt Securities
Amortized cost basis, unrealized gains and losses and fair values of investments in available-for-sale securities
Cost Basis	778	[1]	1,012	[2]
Unrealized Gains	14	[1]	13	[2]
Fair Value	792	[1]	1,025	[2]
FES | Equity securities
Amortized cost basis, unrealized gains and losses and fair values of investments in available-for-sale securities
Cost Basis	281	[1]	104	[2]
Unrealized Gains	13	[1]	20	[2]
Fair Value	294	[1]	124	[2]
OE | Debt Securities
Amortized cost basis, unrealized gains and losses and fair values of investments in available-for-sale securities
Cost Basis	137	[1]	134	[2]
Unrealized Gains	0	[1]	0	[2]
Fair Value	137	[1]	134	[2]
JCP&L | Debt Securities
Amortized cost basis, unrealized gains and losses and fair values of investments in available-for-sale securities
Cost Basis	382	[1]	356	[2]
Unrealized Gains	11	[1]	7	[2]
Fair Value	393	[1]	363	[2]
JCP&L | Equity securities
Amortized cost basis, unrealized gains and losses and fair values of investments in available-for-sale securities
Cost Basis	0	[1]	27	[2]
Unrealized Gains	0	[1]	3	[2]
Fair Value	$ 0	[1]	$ 30	[2]

[1] Excludes short-term cash investments: FE Consolidated - $326 million; FES - $196 million; OE - $4 million; JCP&L - $38 million

[2] Excludes short-term cash investments: FE Consolidated - $164 million; FES - $74 million; OE - $2 million; JCP&L - $19 million