Fair Value Measurements (Details 3) (USD $) In Millions, unless otherwise specified	Mar. 31, 2014		Dec. 31, 2013
Debt Securities
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	$ 1,670	[1]	$ 1,881	[2]
Unrealized Gain	44	[1]	33	[2]
Fair Value	1,714	[1]	1,914	[2]
Equity securities
Amortized cost basis, unrealized gains and losses and fair values of investments in available-for-sale securities
Cost Basis	433	[1]	308	[2]
Unrealized Gains	31	[1]	9	[2]
Fair Value	464	[1]	317	[2]
FES | Debt Securities
Schedule of Available-for-sale Securities [Line Items]
Cost Basis	698	[1]	918	[2]
Unrealized Gain	22	[1]	17	[2]
Fair Value	720	[1]	935	[2]
FES | Equity securities
Amortized cost basis, unrealized gains and losses and fair values of investments in available-for-sale securities
Cost Basis	308	[1]	207	[2]
Unrealized Gains	19	[1]	0	[2]
Fair Value	$ 327	[1]	$ 207	[2]

[1] Excludes short-term cash investments: FE Consolidated - $324 million; FES - $276 million

[2] Excludes short-term cash investments: FE Consolidated - $204 million; FES - $135 million