Total Equity and Other Comprehensive Income (Accumulated Other Comprehensive Income (Loss) Components) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Equity, Beginning Balance		$ 47,688	$ 45,812	$ 55,726
Other comprehensive income (loss), net of tax	$ (736)	(2,128)	(89)	(10,895)
Equity, Ending Balance	49,481	46,723	49,481	46,723
Total
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Equity, Beginning Balance	(9,525)	(8,358)	(10,172)	409
Other comprehensive income (loss), net of tax	(736)	(2,128)	(89)	(10,895)
Equity, Ending Balance	(10,261)	(10,486)	(10,261)	(10,486)
Debt securities
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Equity, Beginning Balance	(6,684)	(6,313)	(7,164)	589
Other comprehensive income (loss), net of tax	(709)	(1,328)	(229)	(8,230)
Equity, Ending Balance	(7,393)	(7,641)	(7,393)	(7,641)
Cash flow hedge derivatives
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Equity, Beginning Balance	(2,544)	(2,081)	(2,705)	(201)
Other comprehensive income (loss), net of tax	(25)	(783)	136	(2,663)
Equity, Ending Balance	(2,569)	(2,864)	(2,569)	(2,864)
Pension and  other postretirement benefit plan adjustments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Equity, Beginning Balance	(254)	74	(251)	27
Other comprehensive income (loss), net of tax		1	(3)	48
Equity, Ending Balance	(254)	75	(254)	75
Other
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Equity, Beginning Balance	(43)	(38)	(52)	(6)
Other comprehensive income (loss), net of tax	(2)	(18)	7	(50)
Equity, Ending Balance	$ (45)	$ (56)	$ (45)	$ (56)