Accumulated Other Comprehensive Loss (Schedule of Accumulated Other Comprehensive Loss) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 13,984	$ 17,530	$ 17,050	$ 14,703
Net change	(1,331)	(165)	(4,182)	(580)
Ending balance	12,434	17,289	12,434	17,289
Accumulated other comprehensive income (loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(3,009)	216	(158)	631
Ending balance	(4,340)	51	(4,340)	51
Unrealized gains (losses) on investment securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(2,940)	259	(95)	640
Net change	(1,343)	(157)	(4,188)	(538)
Ending balance	(4,283)	102	(4,283)	102
Translation adjustments and net investment hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	19	20	19	19
Net change	(1)	0	(1)	1
Ending balance	18	20	18	20
Cash flow hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	27	48	35	82
Net change	(3)	(9)	(11)	(43)
Ending balance	24	39	24	39
Defined benefit pension plans
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(115)	(111)	(117)	(110)
Net change	16	1	18	0
Ending balance	$ (99)	$ (110)	$ (99)	$ (110)