Accumulated Other Comprehensive Loss (Schedule of Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 13,378	$ 15,413	$ 12,859	$ 17,050
Net change	(87)	(1,218)	196	(2,851)
Ending balance	13,532	13,984	13,532	13,984
Accumulated other comprehensive loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(3,776)	(1,791)	(4,059)	(158)
Ending balance	(3,863)	(3,009)	(3,863)	(3,009)
Unrealized gains (losses) on investment securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(3,811)	(1,726)	(4,095)	(95)
Net change	(70)	(1,214)	214	(2,845)
Ending balance	(3,881)	(2,940)	(3,881)	(2,940)
Translation adjustments and net investment hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	18	20	18	19
Net change	3	(1)	3	0
Ending balance	21	19	21	19
Cash flow hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	17	30	18	35
Net change	(20)	(3)	(21)	(8)
Ending balance	(3)	27	(3)	27
Defined benefit pension plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	0	(115)	0	(117)
Net change	0	0	0	2
Ending balance	$ 0	$ (115)	$ 0	$ (115)