Supplemental Guarantor Information (Details) (USD $)	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Consolidating Statements of Income
Revenues	$ 16,258,000,000	[1]	$ 13,339,000,000	[1]	$ 12,973,000,000	[1]
EXPENSES:
Fuel	2,317,000,000		1,432,000,000		1,153,000,000
Purchased power	4,986,000,000		4,624,000,000		4,730,000,000
Other operating expenses	3,909,000,000		2,696,000,000		2,551,000,000
Pension and OPEB mark-to-market	507,000,000		190,000,000		321,000,000
Provision for depreciation	1,121,000,000		768,000,000		757,000,000
General taxes	978,000,000		776,000,000		753,000,000
Impairment of long-lived assets	413,000,000		388,000,000		6,000,000
Total expenses	14,560,000,000		11,596,000,000		11,290,000,000
OPERATING INCOME	1,698,000,000		1,743,000,000		1,683,000,000
OTHER INCOME (EXPENSE):
Investment income	114,000,000		117,000,000		204,000,000
Interest expense	(1,008,000,000)		(845,000,000)		(978,000,000)
Capitalized interest	70,000,000		165,000,000		131,000,000
Total other income (expense)	(255,000,000)		(563,000,000)		(643,000,000)
INCOME (LOSS) BEFORE INCOME TAXES	1,443,000,000		1,180,000,000		1,040,000,000
INCOME TAXES	574,000,000		462,000,000		184,000,000
Net income (loss)	869,000,000		718,000,000		856,000,000
FES Corp
Consolidating Statements of Income
Revenues	5,387,000,000		5,665,000,000		4,390,000,000
EXPENSES:
Fuel	12,000,000		31,000,000		18,000,000
Other operating expenses	574,000,000		314,000,000		220,000,000
Pension and OPEB mark-to-market	10,000,000		11,000,000		13,000,000
Provision for depreciation	4,000,000		3,000,000		4,000,000
General taxes	64,000,000		24,000,000		18,000,000
Impairment of long-lived assets	0		0		0
Total expenses	6,250,000,000		5,916,000,000		4,490,000,000
OPERATING INCOME	(863,000,000)		(251,000,000)		(100,000,000)
OTHER INCOME (EXPENSE):
Investment income	1,000,000		5,000,000		5,000,000
Miscellaneous income, including net income from equity investees	924,000,000		453,000,000		585,000,000
Capitalized interest	0		0		0
Total other income (expense)	829,000,000		362,000,000		546,000,000
INCOME (LOSS) BEFORE INCOME TAXES	(34,000,000)		111,000,000		446,000,000
INCOME TAXES	25,000,000		(120,000,000)		(52,000,000)
Net income (loss)	(59,000,000)		231,000,000		498,000,000
FES Corp | Affiliates
EXPENSES:
Purchased power	4,208,000,000		3,948,000,000		3,221,000,000
OTHER INCOME (EXPENSE):
Interest expense	(2,000,000)		0		0
FES Corp | Non-Affiliates
EXPENSES:
Purchased power	1,378,000,000		1,585,000,000		996,000,000
OTHER INCOME (EXPENSE):
Interest expense	(94,000,000)		(96,000,000)		(44,000,000)
FGCO
Consolidating Statements of Income
Revenues	2,666,000,000		2,435,000,000		2,216,000,000
EXPENSES:
Fuel	1,138,000,000		1,200,000,000		973,000,000
Other operating expenses	427,000,000		357,000,000		377,000,000
Pension and OPEB mark-to-market	68,000,000		37,000,000		56,000,000
Provision for depreciation	127,000,000		100,000,000		122,000,000
General taxes	37,000,000		42,000,000		45,000,000
Impairment of long-lived assets	294,000,000		388,000,000		6,000,000
Total expenses	2,096,000,000		2,154,000,000		1,597,000,000
OPERATING INCOME	570,000,000		281,000,000		619,000,000
OTHER INCOME (EXPENSE):
Investment income	0		1,000,000		0
Miscellaneous income, including net income from equity investees	24,000,000		1,000,000		2,000,000
Capitalized interest	12,000,000		76,000,000		50,000,000
Total other income (expense)	(76,000,000)		(39,000,000)		(53,000,000)
INCOME (LOSS) BEFORE INCOME TAXES	494,000,000		242,000,000		566,000,000
INCOME TAXES	(112,000,000)		74,000,000		196,000,000
Net income (loss)	606,000,000		168,000,000		370,000,000
FGCO | Affiliates
EXPENSES:
Purchased power	5,000,000		30,000,000		18,000,000
OTHER INCOME (EXPENSE):
Interest expense	(3,000,000)		(8,000,000)		(6,000,000)
FGCO | Non-Affiliates
EXPENSES:
Purchased power	0		0		0
OTHER INCOME (EXPENSE):
Interest expense	(109,000,000)		(109,000,000)		(99,000,000)
Nuclear Generation Corp
Consolidating Statements of Income
Revenues	1,647,000,000		1,568,000,000		1,361,000,000
EXPENSES:
Fuel	194,000,000		172,000,000		138,000,000
Other operating expenses	578,000,000		511,000,000		497,000,000
Pension and OPEB mark-to-market	93,000,000		59,000,000		81,000,000
Provision for depreciation	150,000,000		148,000,000		142,000,000
General taxes	23,000,000		28,000,000		24,000,000
Impairment of long-lived assets	0		0		0
Total expenses	1,290,000,000		1,150,000,000		1,104,000,000
OPERATING INCOME	357,000,000		418,000,000		257,000,000
OTHER INCOME (EXPENSE):
Investment income	56,000,000		53,000,000		120,000,000
Miscellaneous income, including net income from equity investees	0		0		0
Capitalized interest	23,000,000		16,000,000		10,000,000
Total other income (expense)	13,000,000		2,000,000		64,000,000
INCOME (LOSS) BEFORE INCOME TAXES	370,000,000		420,000,000		321,000,000
INCOME TAXES	58,000,000		153,000,000		117,000,000
Net income (loss)	312,000,000		267,000,000		204,000,000
Nuclear Generation Corp | Affiliates
EXPENSES:
Purchased power	252,000,000		232,000,000		222,000,000
OTHER INCOME (EXPENSE):
Interest expense	(2,000,000)		(2,000,000)		(4,000,000)
Nuclear Generation Corp | Non-Affiliates
EXPENSES:
Purchased power	0		0		0
OTHER INCOME (EXPENSE):
Interest expense	(64,000,000)		(65,000,000)		(62,000,000)
Eliminations
Consolidating Statements of Income
Revenues	(4,223,000,000)		(3,840,000,000)		(3,239,000,000)
EXPENSES:
Fuel	0		0		0
Other operating expenses	51,000,000		48,000,000		49,000,000
Pension and OPEB mark-to-market	0		0		0
Provision for depreciation	(6,000,000)		(5,000,000)		(6,000,000)
General taxes	0		0		0
Impairment of long-lived assets	0		0		0
Total expenses	(4,178,000,000)		(3,796,000,000)		(3,196,000,000)
OPERATING INCOME	(45,000,000)		(44,000,000)		(43,000,000)
OTHER INCOME (EXPENSE):
Investment income	0		0		0
Miscellaneous income, including net income from equity investees	(918,000,000)		(437,000,000)		(574,000,000)
Capitalized interest	0		0		0
Total other income (expense)	(855,000,000)		(373,000,000)		(511,000,000)
INCOME (LOSS) BEFORE INCOME TAXES	(900,000,000)		(417,000,000)		(554,000,000)
INCOME TAXES	18,000,000		18,000,000		20,000,000
Net income (loss)	(918,000,000)		(435,000,000)		(574,000,000)
Eliminations | Affiliates
EXPENSES:
Purchased power	(4,223,000,000)		(3,839,000,000)		(3,239,000,000)
OTHER INCOME (EXPENSE):
Interest expense	(1,000,000)		0		0
Eliminations | Non-Affiliates
EXPENSES:
Purchased power	0		0		0
OTHER INCOME (EXPENSE):
Interest expense	64,000,000		64,000,000		63,000,000
FES
Consolidating Statements of Income
Revenues	5,477,000,000		5,828,000,000		4,728,000,000
EXPENSES:
Fuel	1,344,000,000		1,403,000,000		1,129,000,000
Other operating expenses	1,630,000,000		1,230,000,000		1,143,000,000
Pension and OPEB mark-to-market	171,000,000		107,000,000		150,000,000
Provision for depreciation	275,000,000		246,000,000		262,000,000
General taxes	124,000,000		94,000,000		87,000,000
Impairment of long-lived assets	294,000,000		388,000,000		6,000,000
Total expenses	5,458,000,000		5,424,000,000		3,995,000,000
OPERATING INCOME	19,000,000		404,000,000		733,000,000
OTHER INCOME (EXPENSE):
Investment income	57,000,000		59,000,000		125,000,000
Miscellaneous income, including net income from equity investees	30,000,000		17,000,000		13,000,000
Interest expense	(211,000,000)		(216,000,000)		(152,000,000)
Capitalized interest	35,000,000		92,000,000		60,000,000
Total other income (expense)	(89,000,000)		(48,000,000)		46,000,000
INCOME (LOSS) BEFORE INCOME TAXES	(70,000,000)		356,000,000		779,000,000
INCOME TAXES	(11,000,000)		125,000,000		281,000,000
Net income (loss)	(59,000,000)		231,000,000		498,000,000
FES | Affiliates
EXPENSES:
Purchased power	242,000,000		371,000,000		222,000,000
OTHER INCOME (EXPENSE):
Interest expense	(8,000,000)		(10,000,000)		(10,000,000)
FES | Non-Affiliates
EXPENSES:
Purchased power	1,378,000,000		1,585,000,000		996,000,000
OTHER INCOME (EXPENSE):
Interest expense	$ (203,000,000)		$ (206,000,000)		$ (142,000,000)

[1] Includes $486 million, $428 million and $395 million of excise tax collections in 2011, 2010 and 2009, respectively.