Accumulated Other Comprehensive Income (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI Beginning Balance	$ 323	$ 389	$ 385	$ 426
Other comprehensive income (loss) before reclassifications	5	25	19	44
Amounts reclassified from AOCI	(29)	(47)	(105)	(103)
Net other comprehensive income (loss)	(24)	(22)	(86)	(59)
AOCI Ending Balance	299	367	299	367
FES
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI Beginning Balance	62	84	72	76
Other comprehensive income (loss) before reclassifications	4	23	17	45
Amounts reclassified from AOCI	(4)	(29)	(27)	(43)
Net other comprehensive income (loss)	0	(6)	(10)	2
AOCI Ending Balance	62	78	62	78
Gains & Losses on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI Beginning Balance	(37)	(39)	(38)	(39)
Other comprehensive income (loss) before reclassifications	0	0	0	1
Amounts reclassified from AOCI	1	0	2	(1)
Net other comprehensive income (loss)	1	0	2	0
AOCI Ending Balance	(36)	(39)	(36)	(39)
Gains & Losses on Cash Flow Hedges | FES
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI Beginning Balance	1	6	3	8
Other comprehensive income (loss) before reclassifications	0	(1)	0	0
Amounts reclassified from AOCI	0	(1)	(2)	(4)
Net other comprehensive income (loss)	0	(2)	(2)	(4)
AOCI Ending Balance	1	4	1	4
Unrealized Gains on AFS Securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI Beginning Balance	13	27	15	19
Other comprehensive income (loss) before reclassifications	5	25	19	38
Amounts reclassified from AOCI	(1)	(25)	(17)	(30)
Net other comprehensive income (loss)	4	0	2	8
AOCI Ending Balance	17	27	17	27
Unrealized Gains on AFS Securities | FES
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI Beginning Balance	12	25	13	16
Other comprehensive income (loss) before reclassifications	4	24	17	37
Amounts reclassified from AOCI	(1)	(25)	(15)	(29)
Net other comprehensive income (loss)	3	(1)	2	8
AOCI Ending Balance	15	24	15	24
Defined Benefit Pension & OPEB Plans
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI Beginning Balance	347	401	408	446
Other comprehensive income (loss) before reclassifications	0	0	0	5
Amounts reclassified from AOCI	(29)	(22)	(90)	(72)
Net other comprehensive income (loss)	(29)	(22)	(90)	(67)
AOCI Ending Balance	318	379	318	379
Defined Benefit Pension & OPEB Plans | FES
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI Beginning Balance	49	53	56	52
Other comprehensive income (loss) before reclassifications	0	0	0	8
Amounts reclassified from AOCI	(3)	(3)	(10)	(10)
Net other comprehensive income (loss)	(3)	(3)	(10)	(2)
AOCI Ending Balance	$ 46	$ 50	$ 46	$ 50