Total Equity and Other Comprehensive Income (Accumulated Other Comprehensive Income (Loss) Components) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Equity, Beginning Balance		$ 49,216	$ 45,812	$ 55,726
Other comprehensive income (loss), net of tax	$ (417)	(2,627)	647	(8,767)
Equity, Ending Balance	49,346	47,688	49,346	47,688
Total
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Equity, Beginning Balance	(9,108)	(5,731)	(10,172)	409
Other comprehensive income (loss), net of tax	(417)	(2,627)	647	(8,767)
Equity, Ending Balance	(9,525)	(8,358)	(9,525)	(8,358)
Debt securities
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Equity, Beginning Balance	(6,500)	(4,238)	(7,164)	589
Other comprehensive income (loss), net of tax	(184)	(2,075)	480	(6,902)
Equity, Ending Balance	(6,684)	(6,313)	(6,684)	(6,313)
Cash flow hedge derivatives
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Equity, Beginning Balance	(2,302)	(1,545)	(2,705)	(201)
Other comprehensive income (loss), net of tax	(242)	(536)	161	(1,880)
Equity, Ending Balance	(2,544)	(2,081)	(2,544)	(2,081)
Pension and  other postretirement benefit plan adjustments
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Equity, Beginning Balance	(259)	68	(251)	27
Other comprehensive income (loss), net of tax	5	6	(3)	47
Equity, Ending Balance	(254)	74	(254)	74
Other
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Equity, Beginning Balance	(47)	(16)	(52)	(6)
Other comprehensive income (loss), net of tax	4	(22)	9	(32)
Equity, Ending Balance	$ (43)	$ (38)	$ (43)	$ (38)