Supplemental Guarantor Information (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended										3 Months Ended	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 FES	Sep. 30, 2012 FES	Sep. 30, 2013 FGCO	Sep. 30, 2012 FGCO	Sep. 30, 2013 Nuclear Generation Corp	Sep. 30, 2012 Nuclear Generation Corp	Sep. 30, 2013 Eliminations	Sep. 30, 2012 Eliminations	Jun. 30, 2013 FES	Sep. 30, 2013 FES	Sep. 30, 2012 FES
Consolidated Statements of Cash Flows [Abstract]
Net cash provided from operating activities			$ 1,671	$ 1,276	$ (1,018)	$ (971)	$ 712	$ 683	$ 705	$ 799	$ (10)	$ (10)		$ 389	$ 501
New Financing-
Long-term debt			2,745	660		0		317		243		0		0	560
Short-term borrowings, net			1,435	1,604	338	982	0	49	0	0	(338)	(1,028)		0	3
Equity contribution from parent					1,500		0		0		0		1,500	1,500	0
Redemptions and Repayments-
Long-term debt			(2,662)	(870)	(769)	0	(352)	(169)	(68)	(87)	10	10		(1,179)	(246)
Short-term borrowings, net					0	0	(32)	0	0	(32)	32	32		0	0
Tender premiums			(110)	0	(67)		0		0		0			(67)	0
Other			(64)	(42)	(3)	(1)	(4)	(6)		(2)		0		(7)	(9)
Net cash provided from (used for) financing activities			654	662	999	981	(388)	191	(68)	122	(296)	(986)		247	308
CASH FLOWS FROM INVESTING ACTIVITIES:
Property additions	(548)	(775)	(1,960)	(1,686)	(9)	(10)	(192)	(175)	(276)	(350)	0	0		(477)	(535)
Nuclear fuel			(159)	(207)	0	0	0	0	(159)	(207)	0	0		(159)	(207)
Proceeds from asset sales					0	0	21	17	0	0	0	0		21	17
Sales of investment securities held in trusts			1,545	2,133	0	0	0	0	650	1,167	0	0		650	1,167
Purchases of investment securities held in trusts			(1,567)	(2,188)	0	0	0	0	(694)	(1,194)	0	0		(694)	(1,194)
Loans to affiliated companies, net					28	1	(156)	(715)	(156)	(337)	306	996		22	(55)
Other			3	(23)	0	(1)	2	(5)	(2)	0	0	0		0	(6)
Net cash used for investing activities			(2,275)	(1,990)	19	(10)	(325)	(878)	(637)	(921)	306	996		(637)	(813)
Net change in cash and cash equivalents			50	(52)	0	0	(1)	(4)	0	0	0	0		(1)	(4)
Cash and cash equivalents at beginning of period			172	202	0	0	3	7	0	0	0	0		3	7
Cash and cash equivalents at end of period	$ 222	$ 150	$ 222	$ 150	$ 0	$ 0	$ 2	$ 3	$ 0	$ 0	$ 0	$ 0		$ 2	$ 3