Supplemental Guarantor Information (Details 1) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Dec. 31, 2011
CURRENT ASSETS:
Cash and cash equivalents	$ 222	$ 172	$ 150	$ 202
Receivables-
Customers	1,579	1,614
Other Receivables	231	315
Materials and supplies, at average cost	731	861
Derivatives	140	160
Prepayments and other	262	208
Total current assets	3,559	3,768
PROPERTY, PLANT AND EQUIPMENT:
In service	44,089	43,210
Less - Accumulated provision for depreciation	13,167	12,600
Property, plant and equipment in service net of accumulated provision for depreciation	30,922	30,610
Construction work in progress	2,301	2,293
Total net property, plant and equipment	33,223	32,903
INVESTMENTS:
Nuclear plant decommissioning trusts	2,183	2,204
Other	876	936
Total other property and investments	3,105	3,194
ASSETS HELD FOR SALE, NET (NOTE 16):	234	0
DEFERRED CHARGES AND OTHER ASSETS:
Goodwill	6,418	6,447	6,444
Other	1,698	1,719
Total deferred charges and other assets	10,262	10,541
Total assets	50,383	50,406	48,738
CURRENT LIABILITIES:
Currently payable long-term debt	1,889	1,999
Accounts payable-
Accrued taxes	401	543
Derivatives	105	126
Other	872	1,038
Total current liabilities	7,955	7,605
CAPITALIZATION:
Total equity	12,544	13,084
Long-term debt and other long-term obligations	15,291	15,179
Total capitalization	27,838	28,272
NONCURRENT LIABILITIES:
Deferred gain on sale and leaseback transaction	866	892
Accumulated deferred income taxes	6,603	6,616
Asset retirement obligations	1,834	1,599
Retirement benefits	3,104	3,080
Other	1,716	1,836
Total noncurrent liabilities	14,590	14,529
Total liabilities and capitalization	50,383	50,406
FES
CURRENT ASSETS:
Cash and cash equivalents	0	0	0	0
Receivables-
Customers	524	483
Affiliated companies	420	232
Other Receivables	76	56
Notes receivable from affiliated companies	337	366
Materials and supplies, at average cost	64	66
Derivatives	139	158
Prepayments and other	61	38
Total current assets	1,621	1,399
PROPERTY, PLANT AND EQUIPMENT:
In service	104	91
Less - Accumulated provision for depreciation	26	32
Property, plant and equipment in service net of accumulated provision for depreciation	78	59
Construction work in progress	21	34
Total net property, plant and equipment	99	93
INVESTMENTS:
Nuclear plant decommissioning trusts	0	0
Investment in affiliated companies	5,503	4,972
Other	1	0
Total other property and investments	5,504	4,972
ASSETS HELD FOR SALE, NET (NOTE 16):	0
DEFERRED CHARGES AND OTHER ASSETS:
Accumulated deferred income tax benefits	16	0
Customer intangibles	99	110
Goodwill	23	24
Property taxes	0	0
Unamortized sale and leaseback costs	0	0
Derivatives	65	99
Other	174	160
Total deferred charges and other assets	377	393
Total assets	7,601	6,857
CURRENT LIABILITIES:
Currently payable long-term debt	1	1
Short-term borrowings	0	0
Accounts payable-
Affiliated companies	643	748
Other	88	63
Accrued taxes	7	126
Derivatives	103	124
Other	46	71
Total current liabilities	1,584	1,491
CAPITALIZATION:
Total equity	5,229	3,763
Long-term debt and other long-term obligations	712	1,482
Total capitalization	5,941	5,245
NONCURRENT LIABILITIES:
Deferred gain on sale and leaseback transaction	0	0
Accumulated deferred income taxes	0	28
Asset retirement obligations	0	0
Retirement benefits	27	26
Derivatives	22	37
Other	27	30
Total noncurrent liabilities	76	121
Total liabilities and capitalization	7,601	6,857
FES | Affiliates
CURRENT LIABILITIES:
Short-term borrowings	696	358
FGCO
CURRENT ASSETS:
Cash and cash equivalents	2	3	3	7
Receivables-
Customers	0	0
Affiliated companies	445	417
Other Receivables	22	19
Notes receivable from affiliated companies	163	7
Materials and supplies, at average cost	161	231
Derivatives	0	0
Prepayments and other	37	39
Total current assets	830	716
PROPERTY, PLANT AND EQUIPMENT:
In service	6,068	5,899
Less - Accumulated provision for depreciation	1,928	1,915
Property, plant and equipment in service net of accumulated provision for depreciation	4,140	3,984
Construction work in progress	115	230
Total net property, plant and equipment	4,255	4,214
INVESTMENTS:
Nuclear plant decommissioning trusts	0	0
Investment in affiliated companies	0	0
Other	10	12
Total other property and investments	10	12
ASSETS HELD FOR SALE, NET (NOTE 16):	121
DEFERRED CHARGES AND OTHER ASSETS:
Accumulated deferred income tax benefits	169	313
Customer intangibles	0	0
Goodwill	0	0
Property taxes	14	14
Unamortized sale and leaseback costs	0	0
Derivatives	0	0
Other	242	194
Total deferred charges and other assets	425	521
Total assets	5,641	5,463
CURRENT LIABILITIES:
Currently payable long-term debt	366	586
Short-term borrowings	4	4
Accounts payable-
Affiliated companies	386	143
Other	125	96
Accrued taxes	17	25
Derivatives	0	0
Other	72	148
Total current liabilities	1,284	1,348
CAPITALIZATION:
Total equity	2,010	1,787
Long-term debt and other long-term obligations	1,873	2,009
Total capitalization	3,883	3,796
NONCURRENT LIABILITIES:
Deferred gain on sale and leaseback transaction	0	0
Accumulated deferred income taxes	0	0
Asset retirement obligations	176	29
Retirement benefits	228	215
Derivatives	0	0
Other	70	75
Total noncurrent liabilities	474	319
Total liabilities and capitalization	5,641	5,463
FGCO | Affiliates
CURRENT LIABILITIES:
Short-term borrowings	314	346
Nuclear Generation Corp
CURRENT ASSETS:
Cash and cash equivalents	0	0	0	0
Receivables-
Customers	0	0
Affiliated companies	285	478
Other Receivables	25	16
Notes receivable from affiliated companies	764	607
Materials and supplies, at average cost	214	208
Derivatives	0	0
Prepayments and other	6	10
Total current assets	1,294	1,319
PROPERTY, PLANT AND EQUIPMENT:
In service	6,719	6,391
Less - Accumulated provision for depreciation	2,882	2,646
Property, plant and equipment in service net of accumulated provision for depreciation	3,837	3,745
Construction work in progress	980	877
Total net property, plant and equipment	4,817	4,622
INVESTMENTS:
Nuclear plant decommissioning trusts	1,270	1,283
Investment in affiliated companies	0	0
Other	0	0
Total other property and investments	1,270	1,283
ASSETS HELD FOR SALE, NET (NOTE 16):	0
DEFERRED CHARGES AND OTHER ASSETS:
Accumulated deferred income tax benefits	0	0
Customer intangibles	0	0
Goodwill	0	0
Property taxes	22	22
Unamortized sale and leaseback costs	0	0
Derivatives	0	0
Other	14	5
Total deferred charges and other assets	36	27
Total assets	7,417	7,251
CURRENT LIABILITIES:
Currently payable long-term debt	514	537
Short-term borrowings	0	0
Accounts payable-
Affiliated companies	378	583
Other	0	0
Accrued taxes	37	20
Derivatives	0	0
Other	22	15
Total current liabilities	951	1,155
CAPITALIZATION:
Total equity	3,469	3,165
Long-term debt and other long-term obligations	789	834
Total capitalization	4,258	3,999
NONCURRENT LIABILITIES:
Deferred gain on sale and leaseback transaction	0	0
Accumulated deferred income taxes	770	714
Asset retirement obligations	983	936
Retirement benefits	0	0
Derivatives	0	0
Other	455	447
Total noncurrent liabilities	2,208	2,097
Total liabilities and capitalization	7,417	7,251
Nuclear Generation Corp | Affiliates
CURRENT LIABILITIES:
Short-term borrowings	0	0
Eliminations
CURRENT ASSETS:
Cash and cash equivalents	0	0	0	0
Receivables-
Customers	0	0
Affiliated companies	(631)	(748)
Other Receivables	0	0
Notes receivable from affiliated companies	(1,010)	(704)
Materials and supplies, at average cost	0	0
Derivatives	0	0
Prepayments and other	1	0
Total current assets	(1,640)	(1,452)
PROPERTY, PLANT AND EQUIPMENT:
In service	(383)	(384)
Less - Accumulated provision for depreciation	(187)	(185)
Property, plant and equipment in service net of accumulated provision for depreciation	(196)	(199)
Construction work in progress	0	0
Total net property, plant and equipment	(196)	(199)
INVESTMENTS:
Nuclear plant decommissioning trusts	0	0
Investment in affiliated companies	(5,503)	(4,972)
Other	0	0
Total other property and investments	(5,503)	(4,972)
ASSETS HELD FOR SALE, NET (NOTE 16):	0
DEFERRED CHARGES AND OTHER ASSETS:
Accumulated deferred income tax benefits	(185)	(313)
Customer intangibles	0	0
Goodwill	0	0
Property taxes	0	0
Unamortized sale and leaseback costs	161	119
Derivatives	0	0
Other	(162)	(106)
Total deferred charges and other assets	(186)	(300)
Total assets	(7,525)	(6,923)
CURRENT LIABILITIES:
Currently payable long-term debt	(22)	(22)
Short-term borrowings	0	0
Accounts payable-
Affiliated companies	(631)	(748)
Other	0	0
Accrued taxes	(19)	0
Derivatives	0	0
Other	36	46
Total current liabilities	(1,646)	(1,428)
CAPITALIZATION:
Total equity	(5,479)	(4,952)
Long-term debt and other long-term obligations	(1,196)	(1,207)
Total capitalization	(6,675)	(6,159)
NONCURRENT LIABILITIES:
Deferred gain on sale and leaseback transaction	866	892
Accumulated deferred income taxes	(71)	(227)
Asset retirement obligations	0	0
Retirement benefits	0	0
Derivatives	0	0
Other	1	(1)
Total noncurrent liabilities	796	664
Total liabilities and capitalization	(7,525)	(6,923)
Eliminations | Affiliates
CURRENT LIABILITIES:
Short-term borrowings	(1,010)	(704)
FES
CURRENT ASSETS:
Cash and cash equivalents	2	3	3	7
Receivables-
Customers	524	483
Affiliated companies	519	379
Other Receivables	123	91
Notes receivable from affiliated companies	254	276
Materials and supplies, at average cost	439	505
Derivatives	139	158
Prepayments and other	105	87
Total current assets	2,105	1,982
PROPERTY, PLANT AND EQUIPMENT:
In service	12,508	11,997
Less - Accumulated provision for depreciation	4,649	4,408
Property, plant and equipment in service net of accumulated provision for depreciation	7,859	7,589
Construction work in progress	1,116	1,141
Total net property, plant and equipment	8,975	8,730
INVESTMENTS:
Nuclear plant decommissioning trusts	1,270	1,283
Investment in affiliated companies	0	0
Other	11	12
Total other property and investments	1,281	1,295
ASSETS HELD FOR SALE, NET (NOTE 16):	121	0
DEFERRED CHARGES AND OTHER ASSETS:
Accumulated deferred income tax benefits	0	0
Customer intangibles	99	110
Goodwill	23	24
Property taxes	36	36
Unamortized sale and leaseback costs	161	119
Derivatives	65	99
Other	268	253
Total deferred charges and other assets	652	641
Total assets	13,134	12,648
CURRENT LIABILITIES:
Currently payable long-term debt	859	1,102
Short-term borrowings	4	4
Accounts payable-
Affiliated companies	776	726
Other	213	159
Accrued taxes	42	171
Derivatives	103	124
Other	176	280
Total current liabilities	2,173	2,566
CAPITALIZATION:
Total equity	5,229	3,763
Long-term debt and other long-term obligations	2,178	3,118
Total capitalization	7,407	6,881
NONCURRENT LIABILITIES:
Deferred gain on sale and leaseback transaction	866	892
Accumulated deferred income taxes	699	515
Asset retirement obligations	1,159	965
Retirement benefits	255	241
Derivatives	22	37
Other	553	551
Total noncurrent liabilities	3,554	3,201
Total liabilities and capitalization	13,134	12,648
FES | Affiliates
CURRENT LIABILITIES:
Short-term borrowings	$ 0	$ 0