Supplemental Guarantor Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012		Mar. 31, 2011
Consolidating Statements of Income
Revenues	$ 4,078	[1]	$ 3,576	[1]
OPERATING EXPENSES:
Fuel	541		453
Purchased power	1,347		1,186
Other operating expenses	812		993
Provision for depreciation	285		225
General taxes	272		237
Total operating expenses	3,332		3,226
OPERATING INCOME (LOSS)	746		350
OTHER INCOME (EXPENSE):
Investment income	11		21
Interest expense	(246)		(231)
Capitalized interest	17		18
Total other income (expense)	(218)		(192)
INCOME (LOSS) BEFORE INCOME TAXES	528		158
INCOME TAXES (BENEFITS)	222		111
NET INCOME	306		47
OTHER COMPREHENSIVE INCOME (LOSS):
Pension and OPEB prior service costs	(53)		(44)
Amortized loss on derivative hedges	(2)		(6)
Change in unrealized gain on available-for-sale securities	10		9
Other comprehensive income (loss)	(45)		(41)
Income taxes (benefits) on other comprehensive income (loss)	(24)		(19)
Other comprehensive income (loss), net of tax	(21)		(22)
COMPREHENSIVE INCOME	285		25
FES Corp
Consolidating Statements of Income
Revenues	1,490		1,366
OPERATING EXPENSES:
Fuel	0		1
Other operating expenses	76		162
Provision for depreciation	1		1
General taxes	20		10
Impairment of long-lived assets			0
Total operating expenses	1,549		1,656
OPERATING INCOME (LOSS)	(59)		(290)
OTHER INCOME (EXPENSE):
Investment income	1		1
Miscellaneous income, including net income from equity investees	258		242
Capitalized interest	0		0
Total other income (expense)	232		218
INCOME (LOSS) BEFORE INCOME TAXES	173		(72)
INCOME TAXES (BENEFITS)	51		(117)
NET INCOME	122		45
OTHER COMPREHENSIVE INCOME (LOSS):
Pension and OPEB prior service costs	(5)		(10)
Amortized loss on derivative hedges	(5)		(9)
Change in unrealized gain on available-for-sale securities	10		8
Other comprehensive income (loss)	0		(11)
Income taxes (benefits) on other comprehensive income (loss)	2		(6)
Other comprehensive income (loss), net of tax	(2)		(5)
COMPREHENSIVE INCOME	120		40
FES Corp | Affiliates
OPERATING EXPENSES:
Purchased power	965		1,185
OTHER INCOME (EXPENSE):
Interest expense	(4)		(1)
FES Corp | Non-Affiliates
OPERATING EXPENSES:
Purchased power	487		297
OTHER INCOME (EXPENSE):
Interest expense	(23)		(24)
FGCO
Consolidating Statements of Income
Revenues	542		743
OPERATING EXPENSES:
Fuel	240		294
Other operating expenses	92		111
Provision for depreciation	30		32
General taxes	10		11
Impairment of long-lived assets			14
Total operating expenses	372		464
OPERATING INCOME (LOSS)	170		279
OTHER INCOME (EXPENSE):
Investment income	4		0
Miscellaneous income, including net income from equity investees	0		1
Capitalized interest	1		5
Total other income (expense)	(22)		(22)
INCOME (LOSS) BEFORE INCOME TAXES	148		257
INCOME TAXES (BENEFITS)	(1)		96
NET INCOME	149		161
OTHER COMPREHENSIVE INCOME (LOSS):
Pension and OPEB prior service costs	(4)		(4)
Amortized loss on derivative hedges	0		0
Change in unrealized gain on available-for-sale securities	0		0
Other comprehensive income (loss)	(4)		(4)
Income taxes (benefits) on other comprehensive income (loss)	(2)		(2)
Other comprehensive income (loss), net of tax	(2)		(2)
COMPREHENSIVE INCOME	147		159
FGCO | Affiliates
OPERATING EXPENSES:
Purchased power	0		2
OTHER INCOME (EXPENSE):
Interest expense	(1)		0
FGCO | Non-Affiliates
OPERATING EXPENSES:
Purchased power	0		0
OTHER INCOME (EXPENSE):
Interest expense	(26)		(28)
Nuclear Generation Corp
Consolidating Statements of Income
Revenues	394		469
OPERATING EXPENSES:
Fuel	55		48
Other operating expenses	116		180
Provision for depreciation	34		38
General taxes	7		8
Impairment of long-lived assets			0
Total operating expenses	274		343
OPERATING INCOME (LOSS)	120		126
OTHER INCOME (EXPENSE):
Investment income	5		5
Miscellaneous income, including net income from equity investees	0		0
Capitalized interest	8		5
Total other income (expense)	5		(7)
INCOME (LOSS) BEFORE INCOME TAXES	125		119
INCOME TAXES (BENEFITS)	23		45
NET INCOME	102		74
OTHER COMPREHENSIVE INCOME (LOSS):
Pension and OPEB prior service costs	0		(6)
Amortized loss on derivative hedges	0		0
Change in unrealized gain on available-for-sale securities	10		8
Other comprehensive income (loss)	10		2
Income taxes (benefits) on other comprehensive income (loss)	4		1
Other comprehensive income (loss), net of tax	6		1
COMPREHENSIVE INCOME	108		75
Nuclear Generation Corp | Affiliates
OPERATING EXPENSES:
Purchased power	62		69
OTHER INCOME (EXPENSE):
Interest expense	(1)		0
Nuclear Generation Corp | Non-Affiliates
OPERATING EXPENSES:
Purchased power	0		0
OTHER INCOME (EXPENSE):
Interest expense	(7)		(17)
Eliminations
Consolidating Statements of Income
Revenues	(910)		(1,187)
OPERATING EXPENSES:
Fuel	0		0
Other operating expenses	11		12
Provision for depreciation	(2)		(2)
General taxes	0		0
Impairment of long-lived assets			0
Total operating expenses	(901)		(1,177)
OPERATING INCOME (LOSS)	(9)		(10)
OTHER INCOME (EXPENSE):
Investment income	(4)		0
Miscellaneous income, including net income from equity investees	(254)		(239)
Capitalized interest	0		0
Total other income (expense)	(239)		(223)
INCOME (LOSS) BEFORE INCOME TAXES	(248)		(233)
INCOME TAXES (BENEFITS)	3		2
NET INCOME	(251)		(235)
OTHER COMPREHENSIVE INCOME (LOSS):
Pension and OPEB prior service costs	4		10
Amortized loss on derivative hedges	0		0
Change in unrealized gain on available-for-sale securities	(10)		(8)
Other comprehensive income (loss)	(6)		2
Income taxes (benefits) on other comprehensive income (loss)	(2)		1
Other comprehensive income (loss), net of tax	(4)		1
COMPREHENSIVE INCOME	(255)		(234)
Eliminations | Affiliates
OPERATING EXPENSES:
Purchased power	(910)		(1,187)
OTHER INCOME (EXPENSE):
Interest expense	4		0
Eliminations | Non-Affiliates
OPERATING EXPENSES:
Purchased power	0		0
OTHER INCOME (EXPENSE):
Interest expense	15		16
FES
Consolidating Statements of Income
Revenues	1,516		1,391
OPERATING EXPENSES:
Fuel	295		343
Other operating expenses	295		465
Provision for depreciation	63		69
General taxes	37		29
Impairment of long-lived assets	0		14
Total operating expenses	1,294		1,286
OPERATING INCOME (LOSS)	222		105
OTHER INCOME (EXPENSE):
Investment income	6		6
Miscellaneous income, including net income from equity investees	4		4
Capitalized interest	9		10
Total other income (expense)	(24)		(34)
INCOME (LOSS) BEFORE INCOME TAXES	198		71
INCOME TAXES (BENEFITS)	76		26
NET INCOME	122		45
OTHER COMPREHENSIVE INCOME (LOSS):
Pension and OPEB prior service costs	(5)		(10)
Amortized loss on derivative hedges	(5)		(9)
Change in unrealized gain on available-for-sale securities	10		8
Other comprehensive income (loss)	0		(11)
Income taxes (benefits) on other comprehensive income (loss)	2		(6)
Other comprehensive income (loss), net of tax	(2)		(5)
COMPREHENSIVE INCOME	120		40
FES | Affiliates
OPERATING EXPENSES:
Purchased power	117		69
OTHER INCOME (EXPENSE):
Interest expense	(2)		(1)
FES | Non-Affiliates
OPERATING EXPENSES:
Purchased power	487		297
OTHER INCOME (EXPENSE):
Interest expense	$ (41)		$ (53)

[1] Includes excise tax collections of $121 million and $119 million in the three months ended March 31, 2012 and 2011, respectively.