Total Equity and Other Comprehensive Income (Accumulated Other Comprehensive Income (Loss) Components) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Equity, Beginning Balance	$ 51,374	$ 49,074	$ 51,141	$ 45,812
Other comprehensive income (loss), net of tax	596	(417)	266	647
Equity, Ending Balance	52,681	49,346	52,681	49,346
Pretax loss included in AOCI from derivatives	285	301	285	301
Total
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Equity, Beginning Balance	(8,042)	(9,108)	(7,712)	(10,172)
Other comprehensive income (loss), net of tax	596	(417)	266	647
Equity, Ending Balance	(7,446)	(9,525)	(7,446)	(9,525)
Debt securities
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Equity, Beginning Balance	(5,966)	(6,500)	(5,830)	(7,164)
Other comprehensive income (loss), net of tax	361	(184)	225	480
Equity, Ending Balance	(5,605)	(6,684)	(5,605)	(6,684)
Cash flow hedge derivatives
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Equity, Beginning Balance	(1,903)	(2,302)	(1,713)	(2,705)
Other comprehensive income (loss), net of tax	234	(242)	44	161
Equity, Ending Balance	(1,669)	(2,544)	(1,669)	(2,544)
Pension and  other postretirement benefit plan adjustments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Equity, Beginning Balance	(127)	(259)	(125)	(251)
Other comprehensive income (loss), net of tax	1	5	(1)	(3)
Equity, Ending Balance	(126)	(254)	(126)	(254)
Other
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Equity, Beginning Balance	(46)	(47)	(44)	(52)
Other comprehensive income (loss), net of tax		4	(2)	9
Equity, Ending Balance	$ (46)	$ (43)	$ (46)	$ (43)