Supplemental Guarantor Information (Details 1) (USD $) In Millions, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2011	Dec. 31, 2010
CURRENT ASSETS:
Cash and cash equivalents	$ 74	$ 202	$ 1,101	$ 1,019
Receivables-
Customers	1,449	1,525
Other	286	269
Materials and supplies, at average cost	927	811
Derivatives	346	235
Prepayments and other	182	122
Total current assets	3,477	3,355
PROPERTY, PLANT AND EQUIPMENT:
In service	40,587	40,122
Less - Accumulated provision for depreciation	12,086	11,839
Property, plant and equipment in service net of accumulated provision for depreciation	28,501	28,283
Construction work in progress	2,065	2,054
Total net property, plant and equipment	30,566	30,337
INVESTMENTS:
Nuclear plant decommissioning trusts		2,112
Other	1,011	1,008
Total other property and investments	3,482	3,522
DEFERRED CHARGES AND OTHER ASSETS:
Goodwill	6,444	6,441	6,507
Other	1,716	1,641
Total deferred charges and other assets	10,166	10,112
Total assets	47,691	47,326	48,565
CURRENT LIABILITIES:
Currently payable long-term debt	1,772	1,621
Short-term borrowings-
Affiliated companies	1,075	0
Accounts payable-
Accrued Taxes	442	558
Derivatives	299	218
Other	1,009	900
Total current liabilities	5,773	4,855
CAPITALIZATION:
Total equity	13,323	13,280
Long-term debt and other long-term obligations	15,527	15,716
Total capitalization	28,866	29,015
NONCURRENT LIABILITIES:
Deferred gain on sale and leaseback transaction	917	925
Accumulated deferred income taxes	5,904	5,670
Asset retirement obligations	1,522	1,497
Retirement benefits	2,240	2,823
Other	2,011	2,072
Total noncurrent liabilities	13,052	13,456
Total liabilities and capitalization	47,691	47,326
FES Corp
CURRENT ASSETS:
Cash and cash equivalents	0	0	0	0
Receivables-
Customers	395	424
Affiliated companies	472	476
Other	50	28
Notes receivable from affiliated companies	81	155
Materials and supplies, at average cost	62	60
Derivatives	322	219
Prepayments and other	7	11
Total current assets	1,389	1,373
PROPERTY, PLANT AND EQUIPMENT:
In service	84	84
Less - Accumulated provision for depreciation	29	28
Property, plant and equipment in service net of accumulated provision for depreciation	55	56
Construction work in progress	31	29
Total net property, plant and equipment	86	85
INVESTMENTS:
Nuclear plant decommissioning trusts	0	0
Investment in affiliated companies	5,956	5,716
Other	0	0
Total other property and investments	5,956	5,716
DEFERRED CHARGES AND OTHER ASSETS:
Accumulated deferred income tax benefits	0	10
Customer intangibles	120	123
Goodwill	24	24
Property taxes	0	0
Unamortized sale and leaseback costs	0	0
Derivatives	117	79
Other	123	89
Total deferred charges and other assets	384	325
Total assets	7,815	7,499
CURRENT LIABILITIES:
Currently payable long-term debt	1	1
Accounts payable-
Affiliated companies	663	777
Other	69	99
Accrued Taxes	31	84
Derivatives	281	189
Other	38	62
Total current liabilities	2,496	2,277
CAPITALIZATION:
Total equity	3,695	3,593
Long-term debt and other long-term obligations	1,482	1,483
Total capitalization	5,177	5,076
NONCURRENT LIABILITIES:
Deferred gain on sale and leaseback transaction	0	0
Accumulated deferred income taxes	18	12
Asset retirement obligations	0	0
Retirement benefits	31	56
Lease market valuation liability	0	0
Other	93	78
Total noncurrent liabilities	142	146
Total liabilities and capitalization	7,815	7,499
FGCO
CURRENT ASSETS:
Cash and cash equivalents	7	7	7	9
Receivables-
Customers	0	0
Affiliated companies	439	643
Other	19	20
Notes receivable from affiliated companies	1,369	1,346
Materials and supplies, at average cost	283	232
Derivatives	0	0
Prepayments and other	17	26
Total current assets	2,134	2,274
PROPERTY, PLANT AND EQUIPMENT:
In service	5,614	5,573
Less - Accumulated provision for depreciation	1,843	1,813
Property, plant and equipment in service net of accumulated provision for depreciation	3,771	3,760
Construction work in progress	171	195
Total net property, plant and equipment	3,942	3,955
INVESTMENTS:
Nuclear plant decommissioning trusts	0	0
Investment in affiliated companies	0	0
Other	7	7
Total other property and investments	7	7
DEFERRED CHARGES AND OTHER ASSETS:
Accumulated deferred income tax benefits	274	307
Customer intangibles	0	0
Goodwill	0	0
Property taxes	20	20
Unamortized sale and leaseback costs	21	5
Derivatives	0	0
Other	111	99
Total deferred charges and other assets	426	431
Total assets	6,509	6,667
CURRENT LIABILITIES:
Currently payable long-term debt	411	411
Accounts payable-
Affiliated companies	175	228
Other	121	121
Accrued Taxes	33	42
Derivatives	0	0
Other	111	141
Total current liabilities	920	1,032
CAPITALIZATION:
Total equity	3,244	3,097
Long-term debt and other long-term obligations	1,903	1,905
Total capitalization	5,147	5,002
NONCURRENT LIABILITIES:
Deferred gain on sale and leaseback transaction	0	0
Accumulated deferred income taxes	0	0
Asset retirement obligations	28	28
Retirement benefits	120	300
Lease market valuation liability	160	171
Other	134	134
Total noncurrent liabilities	442	633
Total liabilities and capitalization	6,509	6,667
Nuclear Generation Corp
CURRENT ASSETS:
Cash and cash equivalents	0	0	0	0
Receivables-
Customers	0	0
Affiliated companies	241	262
Other	53	13
Notes receivable from affiliated companies	44	69
Materials and supplies, at average cost	206	200
Derivatives	0	0
Prepayments and other	1	1
Total current assets	545	545
PROPERTY, PLANT AND EQUIPMENT:
In service	5,689	5,711
Less - Accumulated provision for depreciation	2,524	2,449
Property, plant and equipment in service net of accumulated provision for depreciation	3,165	3,262
Construction work in progress	971	790
Total net property, plant and equipment	4,136	4,052
INVESTMENTS:
Nuclear plant decommissioning trusts	1,240	1,223
Investment in affiliated companies	0	0
Other	0	0
Total other property and investments	1,240	1,223
DEFERRED CHARGES AND OTHER ASSETS:
Accumulated deferred income tax benefits	0	0
Customer intangibles	0	0
Goodwill	0	0
Property taxes	23	23
Unamortized sale and leaseback costs	0	0
Derivatives	0	0
Other	2	3
Total deferred charges and other assets	25	26
Total assets	5,946	5,846
CURRENT LIABILITIES:
Currently payable long-term debt	514	513
Accounts payable-
Affiliated companies	256	211
Other	0	0
Accrued Taxes	24	110
Derivatives	0	0
Other	24	16
Total current liabilities	818	882
CAPITALIZATION:
Total equity	2,697	2,587
Long-term debt and other long-term obligations	641	641
Total capitalization	3,338	3,228
NONCURRENT LIABILITIES:
Deferred gain on sale and leaseback transaction	0	0
Accumulated deferred income taxes	532	510
Asset retirement obligations	891	876
Retirement benefits	0	0
Lease market valuation liability	0	0
Other	367	350
Total noncurrent liabilities	1,790	1,736
Total liabilities and capitalization	5,946	5,846
Eliminations
CURRENT ASSETS:
Cash and cash equivalents	0	0	0	0
Receivables-
Customers	0	0
Affiliated companies	(611)	(781)
Other	0	0
Notes receivable from affiliated companies	(1,482)	(1,187)
Materials and supplies, at average cost	0	0
Derivatives	0	0
Prepayments and other	(1)	0
Total current assets	(2,094)	(1,968)
PROPERTY, PLANT AND EQUIPMENT:
In service	(385)	(385)
Less - Accumulated provision for depreciation	(182)	(180)
Property, plant and equipment in service net of accumulated provision for depreciation	(203)	(205)
Construction work in progress	0	0
Total net property, plant and equipment	(203)	(205)
INVESTMENTS:
Nuclear plant decommissioning trusts	0	0
Investment in affiliated companies	(5,956)	(5,716)
Other	0	0
Total other property and investments	(5,956)	(5,716)
DEFERRED CHARGES AND OTHER ASSETS:
Accumulated deferred income tax benefits	(274)	(317)
Customer intangibles	0	0
Goodwill	0	0
Property taxes	0	0
Unamortized sale and leaseback costs	99	75
Derivatives	0	0
Other	(65)	(62)
Total deferred charges and other assets	(240)	(304)
Total assets	(8,493)	(8,193)
CURRENT LIABILITIES:
Currently payable long-term debt	(21)	(20)
Accounts payable-
Affiliated companies	(611)	(780)
Other	0	0
Accrued Taxes	(13)	(9)
Derivatives	0	0
Other	72	42
Total current liabilities	(2,055)	(1,953)
CAPITALIZATION:
Total equity	(5,941)	(5,700)
Long-term debt and other long-term obligations	(1,229)	(1,230)
Total capitalization	(7,170)	(6,930)
NONCURRENT LIABILITIES:
Deferred gain on sale and leaseback transaction	917	925
Accumulated deferred income taxes	(185)	(236)
Asset retirement obligations	0	0
Retirement benefits	0	0
Lease market valuation liability	0	0
Other	0	1
Total noncurrent liabilities	732	690
Total liabilities and capitalization	(8,493)	(8,193)
FES
CURRENT ASSETS:
Cash and cash equivalents	7	7	7	9
Receivables-
Customers	395	424
Affiliated companies	541	600
Other	122	61
Notes receivable from affiliated companies	12	383
Materials and supplies, at average cost	551	492
Derivatives	322	219
Prepayments and other	24	38
Total current assets	1,974	2,224
PROPERTY, PLANT AND EQUIPMENT:
In service	11,002	10,983
Less - Accumulated provision for depreciation	4,214	4,110
Property, plant and equipment in service net of accumulated provision for depreciation	6,788	6,873
Construction work in progress	1,173	1,014
Total net property, plant and equipment	7,961	7,887
INVESTMENTS:
Nuclear plant decommissioning trusts	1,240	1,223
Investment in affiliated companies	0	0
Other	7	7
Total other property and investments	1,247	1,230
DEFERRED CHARGES AND OTHER ASSETS:
Accumulated deferred income tax benefits	0	0
Customer intangibles	120	123
Goodwill	24	24
Property taxes	43	43
Unamortized sale and leaseback costs	120	80
Derivatives	117	79
Other	171	129
Total deferred charges and other assets	595	478
Total assets	11,777	11,819
CURRENT LIABILITIES:
Currently payable long-term debt	905	905
Accounts payable-
Affiliated companies	483	436
Other	190	220
Accrued Taxes	75	227
Derivatives	281	189
Other	245	261
Total current liabilities	2,179	2,238
CAPITALIZATION:
Total equity	3,695	3,577
Long-term debt and other long-term obligations	2,797	2,799
Total capitalization	6,492	6,376
NONCURRENT LIABILITIES:
Deferred gain on sale and leaseback transaction	917	925
Accumulated deferred income taxes	365	286
Asset retirement obligations	919	904
Retirement benefits	151	356
Lease market valuation liability	160	171
Other	594	563
Total noncurrent liabilities	3,106	3,205
Total liabilities and capitalization	11,777	11,819
Affiliates [Member] | FES Corp
Short-term borrowings-
Affiliated companies	1,413	1,065
Affiliates [Member] | FGCO
Short-term borrowings-
Affiliated companies	69	89
Affiliates [Member] | Nuclear Generation Corp
Short-term borrowings-
Affiliated companies	0	32
Affiliates [Member] | Eliminations
Short-term borrowings-
Affiliated companies	(1,482)	(1,186)
Affiliates [Member] | FES
Short-term borrowings-
Affiliated companies	$ 0	$ 0