Accumulated Other Comprehensive Income (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI Beginning Balance	$ 361	$ 405	$ 385	$ 426
Other comprehensive income before reclassifications	(1)	5	14	19
Amounts reclassified from AOCI	(37)	(21)	(76)	(56)
Net other comprehensive income (loss)	(38)	(16)	(62)	(37)
AOCI Ending Balance	323	389	323	389
FES
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI Beginning Balance	71	74	72	76
Other comprehensive income before reclassifications	(1)	13	13	22
Amounts reclassified from AOCI	(8)	(3)	(23)	(14)
Net other comprehensive income (loss)	(9)	10	(10)	8
AOCI Ending Balance	62	84	62	84
Gains & Losses on Cash Flow Hedges
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI Beginning Balance	(37)	(42)	(38)	(39)
Other comprehensive income before reclassifications	0	1	0	1
Amounts reclassified from AOCI	0	2	1	(1)
Net other comprehensive income (loss)	0	3	1	0
AOCI Ending Balance	(37)	(39)	(37)	(39)
Gains & Losses on Cash Flow Hedges | FES
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI Beginning Balance	2	4	3	8
Other comprehensive income before reclassifications	0	1	0	1
Amounts reclassified from AOCI	(1)	1	(2)	(3)
Net other comprehensive income (loss)	(1)	2	(2)	(2)
AOCI Ending Balance	1	6	1	6
Unrealized Gains on AFS Securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI Beginning Balance	18	25	15	19
Other comprehensive income before reclassifications	(1)	4	14	13
Amounts reclassified from AOCI	(4)	(2)	(16)	(5)
Net other comprehensive income (loss)	(5)	2	(2)	8
AOCI Ending Balance	13	27	13	27
Unrealized Gains on AFS Securities | FES
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI Beginning Balance	17	22	13	16
Other comprehensive income before reclassifications	(1)	4	13	13
Amounts reclassified from AOCI	(4)	(1)	(14)	(4)
Net other comprehensive income (loss)	(5)	3	(1)	9
AOCI Ending Balance	12	25	12	25
Defined Benefit Pension & OPEB Plans
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI Beginning Balance	380	422	408	446
Other comprehensive income before reclassifications	0	0	0	5
Amounts reclassified from AOCI	(33)	(21)	(61)	(50)
Net other comprehensive income (loss)	(33)	(21)	(61)	(45)
AOCI Ending Balance	347	401	347	401
Defined Benefit Pension & OPEB Plans | FES
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
AOCI Beginning Balance	52	48	56	52
Other comprehensive income before reclassifications	0	8	0	8
Amounts reclassified from AOCI	(3)	(3)	(7)	(7)
Net other comprehensive income (loss)	(3)	5	(7)	1
AOCI Ending Balance	$ 49	$ 53	$ 49	$ 53