Supplemental Guarantor Information (Details 1) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2011	Dec. 31, 2010
CURRENT ASSETS:
Cash and cash equivalents	$ 150	$ 202	$ 291	$ 1,019
Receivables-
Customers	1,604	1,525
Other	227	269
Materials and supplies, at average cost	875	811
Derivatives	212	235
Prepayments and other	190	122
Total current assets	3,709	3,355
PROPERTY, PLANT AND EQUIPMENT:
In service	41,756	40,122
Less - Accumulated provision for depreciation	12,434	11,839
Property, plant and equipment in service net of accumulated provision for depreciation	29,322	28,283
Construction work in progress	2,119	2,054
Total net property, plant and equipment	31,441	30,337
INVESTMENTS:
Nuclear plant decommissioning trusts	2,203	2,112
Other	1,038	1,008
Total other property and investments	3,451	3,522
DEFERRED CHARGES AND OTHER ASSETS:
Goodwill	6,444	6,441	6,428
Other	1,580	1,641
Total deferred charges and other assets	10,137	10,112
Total assets	48,738	47,326	48,673
CURRENT LIABILITIES:
Currently payable long-term debt	1,473	1,621
Short-term borrowings-
Affiliated companies	1,604	0
Accounts payable-
Accrued Taxes	508	558
Derivatives	155	218
Other	942	900
Total current liabilities	5,920	4,855
CAPITALIZATION:
Total equity	13,433	13,280
Long-term debt and other long-term obligations	15,627	15,716
Total capitalization	29,076	29,015
NONCURRENT LIABILITIES:
Deferred gain on sale and leaseback transaction	900	925
Accumulated deferred income taxes	6,543	5,670
Asset retirement obligations	1,574	1,497
Retirement benefits	2,271	2,823
Other	1,904	2,072
Total noncurrent liabilities	13,742	13,456
Total liabilities and capitalization	48,738	47,326
FES Corp
CURRENT ASSETS:
Cash and cash equivalents	0	0	0	0
Receivables-
Customers	485	424
Affiliated companies	362	476
Other	63	28
Notes receivable from affiliated companies	153	155
Materials and supplies, at average cost	66	60
Derivatives	209	219
Prepayments and other	85	11
Total current assets	1,423	1,373
PROPERTY, PLANT AND EQUIPMENT:
In service	89	84
Less - Accumulated provision for depreciation	31	28
Property, plant and equipment in service net of accumulated provision for depreciation	58	56
Construction work in progress	32	29
Total net property, plant and equipment	90	85
INVESTMENTS:
Nuclear plant decommissioning trusts	0	0
Investment in affiliated companies	6,555	5,700
Other	5	0
Total other property and investments	6,560	5,700
DEFERRED CHARGES AND OTHER ASSETS:
Accumulated deferred income tax benefits	0	10
Customer intangibles	114	123
Goodwill	24	24
Property taxes	0	0
Unamortized sale and leaseback costs	0	0
Derivatives	78	79
Other	127	89
Total deferred charges and other assets	343	325
Total assets	8,416	7,483
CURRENT LIABILITIES:
Currently payable long-term debt	1	1
Accounts payable-
Affiliated companies	618	777
Other	82	99
Accrued Taxes	49	84
Derivatives	153	189
Other	50	62
Total current liabilities	3,001	2,277
CAPITALIZATION:
Total equity	3,802	3,577
Long-term debt and other long-term obligations	1,482	1,483
Total capitalization	5,284	5,060
NONCURRENT LIABILITIES:
Deferred gain on sale and leaseback transaction	0	0
Accumulated deferred income taxes	39	12
Asset retirement obligations	0	0
Retirement benefits	35	56
Lease market valuation liability	0	0
Other	57	78
Total noncurrent liabilities	131	146
Total liabilities and capitalization	8,416	7,483
FGCO
CURRENT ASSETS:
Cash and cash equivalents	3	7	6	9
Receivables-
Customers	0	0
Affiliated companies	410	643
Other	15	20
Notes receivable from affiliated companies	2,061	1,346
Materials and supplies, at average cost	257	232
Derivatives	0	0
Prepayments and other	24	26
Total current assets	2,770	2,274
PROPERTY, PLANT AND EQUIPMENT:
In service	5,730	5,573
Less - Accumulated provision for depreciation	1,888	1,813
Property, plant and equipment in service net of accumulated provision for depreciation	3,842	3,760
Construction work in progress	203	195
Total net property, plant and equipment	4,045	3,955
INVESTMENTS:
Nuclear plant decommissioning trusts	0	0
Investment in affiliated companies	0	0
Other	11	7
Total other property and investments	11	7
DEFERRED CHARGES AND OTHER ASSETS:
Accumulated deferred income tax benefits	270	307
Customer intangibles	0	0
Goodwill	0	0
Property taxes	20	20
Unamortized sale and leaseback costs	0	5
Derivatives	0	0
Other	163	99
Total deferred charges and other assets	453	431
Total assets	7,279	6,667
CURRENT LIABILITIES:
Currently payable long-term debt	565	411
Accounts payable-
Affiliated companies	311	228
Other	92	121
Accrued Taxes	19	42
Derivatives	0	0
Other	154	141
Total current liabilities	1,276	1,032
CAPITALIZATION:
Total equity	3,651	3,097
Long-term debt and other long-term obligations	1,976	1,905
Total capitalization	5,627	5,002
NONCURRENT LIABILITIES:
Deferred gain on sale and leaseback transaction	0	0
Accumulated deferred income taxes	0	0
Asset retirement obligations	29	28
Retirement benefits	148	300
Lease market valuation liability	87	171
Other	112	134
Total noncurrent liabilities	376	633
Total liabilities and capitalization	7,279	6,667
Nuclear Generation Corp
CURRENT ASSETS:
Cash and cash equivalents	0	0	0	0
Receivables-
Customers	0	0
Affiliated companies	238	262
Other	25	13
Notes receivable from affiliated companies	406	69
Materials and supplies, at average cost	210	200
Derivatives	0	0
Prepayments and other	27	1
Total current assets	906	545
PROPERTY, PLANT AND EQUIPMENT:
In service	6,204	5,711
Less - Accumulated provision for depreciation	2,578	2,449
Property, plant and equipment in service net of accumulated provision for depreciation	3,626	3,262
Construction work in progress	820	790
Total net property, plant and equipment	4,446	4,052
INVESTMENTS:
Nuclear plant decommissioning trusts	1,286	1,223
Investment in affiliated companies	0	0
Other	0	0
Total other property and investments	1,286	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	6,663	5,846
CURRENT LIABILITIES:
Currently payable long-term debt	529	513
Accounts payable-
Affiliated companies	463	211
Other	0	0
Accrued Taxes	19	110
Derivatives	0	0
Other	24	16
Total current liabilities	1,035	882
CAPITALIZATION:
Total equity	2,886	2,587
Long-term debt and other long-term obligations	845	641
Total capitalization	3,731	3,228
NONCURRENT LIABILITIES:
Deferred gain on sale and leaseback transaction	0	0
Accumulated deferred income taxes	624	510
Asset retirement obligations	921	876
Retirement benefits	0	0
Lease market valuation liability	0	0
Other	352	350
Total noncurrent liabilities	1,897	1,736
Total liabilities and capitalization	6,663	5,846
Eliminations
CURRENT ASSETS:
Cash and cash equivalents	0	0	0	0
Receivables-
Customers	0	0
Affiliated companies	(608)	(781)
Other	0	0
Notes receivable from affiliated companies	(2,182)	(1,187)
Materials and supplies, at average cost	0	0
Derivatives	0	0
Prepayments and other	1	0
Total current assets	(2,789)	(1,968)
PROPERTY, PLANT AND EQUIPMENT:
In service	(385)	(385)
Less - Accumulated provision for depreciation	(185)	(180)
Property, plant and equipment in service net of accumulated provision for depreciation	(200)	(205)
Construction work in progress	0	0
Total net property, plant and equipment	(200)	(205)
INVESTMENTS:
Nuclear plant decommissioning trusts	0	0
Investment in affiliated companies	(6,555)	(5,700)
Other	0	0
Total other property and investments	(6,555)	(5,700)
DEFERRED CHARGES AND OTHER ASSETS:
Accumulated deferred income tax benefits	(270)	(317)
Customer intangibles	0	0
Goodwill	0	0
Property taxes	0	0
Unamortized sale and leaseback costs	111	75
Derivatives	0	0
Other	(111)	(62)
Total deferred charges and other assets	(270)	(304)
Total assets	(9,814)	(8,177)
CURRENT LIABILITIES:
Currently payable long-term debt	(21)	(20)
Accounts payable-
Affiliated companies	(605)	(780)
Other	0	0
Accrued Taxes	(4)	(9)
Derivatives	0	0
Other	16	42
Total current liabilities	(2,797)	(1,953)
CAPITALIZATION:
Total equity	(6,537)	(5,684)
Long-term debt and other long-term obligations	(1,218)	(1,230)
Total capitalization	(7,755)	(6,914)
NONCURRENT LIABILITIES:
Deferred gain on sale and leaseback transaction	900	925
Accumulated deferred income taxes	(162)	(236)
Asset retirement obligations	0	0
Retirement benefits	0	0
Lease market valuation liability	0	0
Other	0	1
Total noncurrent liabilities	738	690
Total liabilities and capitalization	(9,814)	(8,177)
FES
CURRENT ASSETS:
Cash and cash equivalents	3	7	6	9
Receivables-
Customers	485	424
Affiliated companies	402	600
Other	103	61
Notes receivable from affiliated companies	438	383
Materials and supplies, at average cost	533	492
Derivatives	209	219
Prepayments and other	137	38
Total current assets	2,310	2,224
PROPERTY, PLANT AND EQUIPMENT:
In service	11,638	10,983
Less - Accumulated provision for depreciation	4,312	4,110
Property, plant and equipment in service net of accumulated provision for depreciation	7,326	6,873
Construction work in progress	1,055	1,014
Total net property, plant and equipment	8,381	7,887
INVESTMENTS:
Nuclear plant decommissioning trusts	1,286	1,223
Investment in affiliated companies	0	0
Other	16	7
Total other property and investments	1,302	1,230
DEFERRED CHARGES AND OTHER ASSETS:
Accumulated deferred income tax benefits	0	0
Customer intangibles	114	123
Goodwill	24	24
Property taxes	43	43
Unamortized sale and leaseback costs	111	80
Derivatives	78	79
Other	181	129
Total deferred charges and other assets	551	478
Total assets	12,544	11,819
CURRENT LIABILITIES:
Currently payable long-term debt	1,074	905
Accounts payable-
Affiliated companies	787	436
Other	174	220
Accrued Taxes	83	227
Derivatives	153	189
Other	244	261
Total current liabilities	2,515	2,238
CAPITALIZATION:
Total equity	3,802	3,577
Long-term debt and other long-term obligations	3,085	2,799
Total capitalization	6,887	6,376
NONCURRENT LIABILITIES:
Deferred gain on sale and leaseback transaction	900	925
Accumulated deferred income taxes	501	286
Asset retirement obligations	950	904
Retirement benefits	183	356
Lease market valuation liability	87	171
Other	521	563
Total noncurrent liabilities	3,142	3,205
Total liabilities and capitalization	12,544	11,819
Affiliates | FES Corp
Short-term borrowings-
Affiliated companies	2,048	1,065
Affiliates | FGCO
Short-term borrowings-
Affiliated companies	135	89
Affiliates | Nuclear Generation Corp
Short-term borrowings-
Affiliated companies	0	32
Affiliates | Eliminations
Short-term borrowings-
Affiliated companies	(2,183)	(1,186)
Affiliates | FES
Short-term borrowings-
Affiliated companies	$ 0	$ 0