Total Equity and Other Comprehensive Income (Accumulated Other Comprehensive Income (Loss) Components) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Equity, Beginning Balance	$ 52,681	$ 49,346	$ 51,141	$ 45,812
Other comprehensive income (loss), net of tax	2,356	(736)	2,622	(89)
Equity, Ending Balance	55,729	49,481	55,729	49,481
Pretax loss included in AOCI from derivatives	280	297	280	297
Total
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Equity, Beginning Balance	(7,446)	(9,525)	(7,712)	(10,172)
Other comprehensive income (loss), net of tax	2,356	(736)	2,622	(89)
Equity, Ending Balance	(5,090)	(10,261)	(5,090)	(10,261)
Debt securities
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Equity, Beginning Balance	(5,605)	(6,684)	(5,830)	(7,164)
Other comprehensive income (loss), net of tax	1,232	(709)	1,457	(229)
Equity, Ending Balance	(4,373)	(7,393)	(4,373)	(7,393)
Cash flow hedge derivatives
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Equity, Beginning Balance	(1,669)	(2,544)	(1,713)	(2,705)
Other comprehensive income (loss), net of tax	1,121	(25)	1,165	136
Equity, Ending Balance	(548)	(2,569)	(548)	(2,569)
Pension and  other postretirement benefit plan adjustments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Equity, Beginning Balance	(126)	(254)	(125)	(251)
Other comprehensive income (loss), net of tax			(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)	(43)	(44)	(52)
Other comprehensive income (loss), net of tax	3	(2)	1	7
Equity, Ending Balance	$ (43)	$ (45)	$ (43)	$ (45)