Supplemental Guarantor Information (Details 2) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Consolidated Statements of Cash Flows [Abstract]
Net cash provided from operating activities	$ 2,320	$ 3,063	$ 3,076
New Financing-
Long-term debt	750	604	1,099
Short-term borrowings, net	1,969	0	0
Redemptions and Repayments-
Long-term debt	(940)	(1,909)	(1,015)
Short-term borrowings, net	0	(700)	(378)
Common stock dividend payments	(920)	(881)	(670)
Other	(52)	(38)	(19)
Net cash provided from (used for) financing activities	807	(2,924)	(983)
CASH FLOWS FROM INVESTING ACTIVITIES:
Property additions	(2,678)	(2,129)	(1,780)
Nuclear fuel	(286)	(149)	(183)
Proceeds from asset sales	17	840	117
Sales of investment securities held in trusts	2,980	4,207	3,172
Purchases of investment securities held in trusts	(3,020)	(4,309)	(3,219)
Customer acquisition costs	(2)	(3)	(113)
Other	(41)	51	27
Net cash used for investing activities	(3,157)	(956)	(1,948)
Net change in cash and cash equivalents	(30)	(817)	145
Cash and cash equivalents at beginning of period	202	1,019	874
Cash and cash equivalents at end of period	172	202	1,019
FES Corp
Consolidated Statements of Cash Flows [Abstract]
Net cash provided from operating activities	(1,063)	(790)	(260)
New Financing-
Long-term debt	0	0	0
Short-term borrowings, net	0	1,065	0
Redemptions and Repayments-
Long-term debt	(1)	(136)	(1)
Short-term borrowings, net	(707)
Common stock dividend payments	0
Other	(1)	(9)	0
Net cash provided from (used for) financing activities	(709)	920	(1)
CASH FLOWS FROM INVESTING ACTIVITIES:
Property additions	(14)	(24)	(9)
Nuclear fuel	0	0	0
Proceeds from asset sales	0	9	0
Sales of investment securities held in trusts	0	0	0
Purchases of investment securities held in trusts	0	0	0
Loans to affiliated companies, net	(211)	(120)	382
Customer acquisition costs	(2)	(3)	(113)
Dividend received	2,000
Leasehold improvement payments to associated companies			0
Other	(1)	8	1
Net cash used for investing activities	1,772	(130)	261
Net change in cash and cash equivalents	0	0	0
Cash and cash equivalents at beginning of period	0	0	0
Cash and cash equivalents at end of period	0	0	0
FGCO
Consolidated Statements of Cash Flows [Abstract]
Net cash provided from operating activities	639	926	380
New Financing-
Long-term debt	351	140	318
Short-term borrowings, net	260	78	2
Redemptions and Repayments-
Long-term debt	(288)	(362)	(341)
Short-term borrowings, net	0
Common stock dividend payments	(2,000)
Other	(8)	(1)	(1)
Net cash provided from (used for) financing activities	(1,685)	(145)	(22)
CASH FLOWS FROM INVESTING ACTIVITIES:
Property additions	(273)	(205)	(518)
Nuclear fuel	0	0	0
Proceeds from asset sales	17	590	117
Sales of investment securities held in trusts	0	0	0
Purchases of investment securities held in trusts	0	0	0
Loans to affiliated companies, net	1,338	(1,157)	52
Customer acquisition costs	0	0	0
Dividend received	0
Leasehold improvement payments to associated companies			0
Other	(40)	(11)	0
Net cash used for investing activities	1,042	(783)	(349)
Net change in cash and cash equivalents	(4)	(2)	9
Cash and cash equivalents at beginning of period	7	9	0
Cash and cash equivalents at end of period	3	7	9
Nuclear Generation Corp
Consolidated Statements of Cash Flows [Abstract]
Net cash provided from operating activities	1,266	702	685
New Financing-
Long-term debt	299	107	397
Short-term borrowings, net	0	32	0
Redemptions and Repayments-
Long-term debt	(161)	(377)	(449)
Short-term borrowings, net	(32)
Common stock dividend payments	0
Other	(3)	(1)	(1)
Net cash provided from (used for) financing activities	103	(239)	(53)
CASH FLOWS FROM INVESTING ACTIVITIES:
Property additions	(508)	(371)	(325)
Nuclear fuel	(286)	(149)	(183)
Proceeds from asset sales	0	0	0
Sales of investment securities held in trusts	1,464	1,843	1,927
Purchases of investment securities held in trusts	(1,502)	(1,890)	(1,974)
Loans to affiliated companies, net	(538)	105	(26)
Customer acquisition costs	0	0	0
Dividend received	0
Leasehold improvement payments to associated companies			(51)
Other	1	(1)	0
Net cash used for investing activities	(1,369)	(463)	(632)
Net change in cash and cash equivalents	0	0	0
Cash and cash equivalents at beginning of period	0	0	0
Cash and cash equivalents at end of period	0	0	0
Eliminations
Consolidated Statements of Cash Flows [Abstract]
Net cash provided from operating activities	(21)	(19)	(19)
New Financing-
Long-term debt	0	0	0
Short-term borrowings, net	(257)	(1,186)	0
Redemptions and Repayments-
Long-term debt	21	19	19
Short-term borrowings, net	739
Common stock dividend payments	2,000
Other		0	0
Net cash provided from (used for) financing activities	2,503	(1,167)	19
CASH FLOWS FROM INVESTING ACTIVITIES:
Property additions	0	0	0
Nuclear fuel	0	0	0
Proceeds from asset sales	0	0	0
Sales of investment securities held in trusts	0	0	0
Purchases of investment securities held in trusts	0	0	0
Loans to affiliated companies, net	(482)	1,186	0
Customer acquisition costs	0	0	0
Dividend received	(2,000)
Leasehold improvement payments to associated companies			0
Other	0	0	0
Net cash used for investing activities	(2,482)	1,186	0
Net change in cash and cash equivalents	0	0	0
Cash and cash equivalents at beginning of period	0	0	0
Cash and cash equivalents at end of period	0	0	0
FES
Consolidated Statements of Cash Flows [Abstract]
Net cash provided from operating activities	821	819	786
New Financing-
Long-term debt	650	247	715
Short-term borrowings, net	3	(11)	2
Redemptions and Repayments-
Long-term debt	(429)	(856)	(772)
Short-term borrowings, net	0	0	0
Common stock dividend payments	0
Other	(12)	(11)	(2)
Net cash provided from (used for) financing activities	212	(631)	(57)
CASH FLOWS FROM INVESTING ACTIVITIES:
Property additions	(795)	(600)	(852)
Nuclear fuel	(286)	(149)	(183)
Proceeds from asset sales	17	599	117
Sales of investment securities held in trusts	1,464	1,843	1,927
Purchases of investment securities held in trusts	(1,502)	(1,890)	(1,974)
Loans to affiliated companies, net	107	14	408
Customer acquisition costs	(2)	(3)	(113)
Dividend received	0
Leasehold improvement payments to associated companies			(51)
Other	(40)	(4)	1
Net cash used for investing activities	(1,037)	(190)	(720)
Net change in cash and cash equivalents	(4)	(2)	9
Cash and cash equivalents at beginning of period	7	9	0
Cash and cash equivalents at end of period	$ 3	$ 7	$ 9