Accumulated Other Comprehensive Income (Details 1) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Other operating expenses	$ 901	$ 858	$ 1,021	$ 1,182	$ 948	$ 877	$ 886	$ 882	$ 3,962	$ 3,593	$ 3,760
Interest expense - other									1,073	1,016	1,001
Investment income									(72)	(33)	(77)
Total before taxes									(171)	(570)	(1,300)
Income taxes (benefits)	(268)	152	26	48	66	77	(62)	114	(42)	195	545
Net of tax	306	(333)	(64)	(208)	(142)	(218)	164	(196)	(299)	(392)	(771)
FES
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Other operating expenses	359	356	468	452	382	339	387	379	1,635	1,487	1,356
Investment income									(61)	(16)	(66)
Total before taxes									588	(52)	(276)
Income taxes (benefits)	(133)	28	(67)	(56)	25	23	(42)	0	(228)	6	103
Net of tax	214	(44)	87	(13)	(89)	(40)	71	(2)	244	(60)	(187)
Reclassifications from AOCI | Gains & losses on cash flow hedges
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Total before taxes									(2)	3	1
Income taxes (benefits)									1	(1)	0
Net of tax									(1)	2	1
Reclassifications from AOCI | Gains & losses on cash flow hedges | FES
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Total before taxes									(10)	(6)	(9)
Income taxes (benefits)									4	2	4
Net of tax									(6)	(4)	(5)
Reclassifications from AOCI | Gains & losses on cash flow hedges | Commodity contracts
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Other operating expenses									(10)	(8)	(9)
Reclassifications from AOCI | Gains & losses on cash flow hedges | Commodity contracts | FES
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Other operating expenses									(10)	(8)	(9)
Reclassifications from AOCI | Gains & losses on cash flow hedges | Long-term debt
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Interest expense - other									8	11	10
Reclassifications from AOCI | Gains & losses on cash flow hedges | Long-term debt | FES
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Interest expense - other									0	2	0
Reclassifications from AOCI | Unrealized gains on AFS securities
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Investment income									(63)	(56)	(72)
Income taxes (benefits)									24	21	27
Net of tax									(39)	(35)	(45)
Reclassifications from AOCI | Unrealized gains on AFS securities | FES
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Investment income									(59)	(49)	(65)
Income taxes (benefits)									22	18	24
Net of tax									(37)	(31)	(41)
Reclassifications from AOCI | Defined benefit pension and OPEB plans
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Prior-service costs									(168)	(195)	(191)
Income taxes (benefits)									65	75	74
Net of tax									(103)	(120)	(117)
Reclassifications from AOCI | Defined benefit pension and OPEB plans | FES
Reclassification Out of Accumulated Other Comprehensive Income [Line Items]
Prior-service costs									(19)	(20)	(20)
Income taxes (benefits)									7	8	8
Net of tax									$ (12)	$ (12)	$ (12)