Components of Other Comprehensive Income (Loss), Net - EEGH (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance	$ 47,051	$ 32,572	$ 46,977	$ 32,578
Other comprehensive income (loss)	84	128	196	(419)
Balance	49,365	33,785	49,365	33,785
EEGH
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance	7,078	10,078	6,995	10,229
Other comprehensive income (loss)	5	0	17	(84)
Balance	7,398	8,456	7,398	8,456
Unrecognized Amounts on Retirement Benefits
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance			(492)	(417)
Other comprehensive income (loss)			22	44
Balance	(470)	(373)	(470)	(373)
Unrecognized Amounts on Retirement Benefits | EEGH
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance			(12)	(106)
Other comprehensive income (loss)			4	3
Balance	(8)	(103)	(8)	(103)
Unrealized Losses on Cash Flow Hedges
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance			(8)	7
Other comprehensive income (loss)			15	(24)
Balance	7	(17)	7	(17)
Unrealized Losses on Cash Flow Hedges | EEGH
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance			(51)	(81)
Other comprehensive income (loss)			13	(87)
Balance	(38)	(168)	(38)	(168)
Noncontrolling Interest
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance			(10)	0
Other comprehensive income (loss)			4	0
Balance	(6)	0	(6)	0
Noncontrolling Interest | EEGH
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance			(10)	0
Other comprehensive income (loss)			4	0
Balance	(6)	0	(6)	0
Accumulated Other Comprehensive (Loss) Income, Net
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance	(1,440)	(2,253)	(1,552)	(1,706)
Other comprehensive income (loss)	80	128	192	(419)
Balance	(1,360)	(2,125)	(1,360)	(2,125)
Accumulated Other Comprehensive (Loss) Income, Net | EEGH
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Balance	(45)	(271)	(53)	(187)
Other comprehensive income (loss)	5		13	(84)
Balance	$ (40)	$ (271)	$ (40)	$ (271)