Accumulated Other Comprehensive Loss - Schedule of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 14,232	$ 13,580	$ 13,903	$ 13,703
Net change	43	(20)	705	(193)
Ending balance	14,547	13,699	14,547	13,699
Accumulated other comprehensive loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(3,262)	(3,989)	(3,924)	(3,816)
Net change	43	(20)	705	(193)
Ending balance	(3,219)	(4,009)	(3,219)	(4,009)
Available-for-sale securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(2,665)	(3,317)	(3,307)	(3,146)
Net change	18	(36)	660	(207)
Ending balance	(2,647)	(3,353)	(2,647)	(3,353)
Held-to-maturity securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(601)	(667)	(616)	(682)
Net change	17	17	32	32
Ending balance	(584)	(650)	(584)	(650)
Translation adjustments and net investment hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	20	20	20	21
Net change	2	0	2	(1)
Ending balance	22	20	22	20
Cash flow hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(16)	(25)	(21)	(9)
Net change	6	(1)	11	(17)
Ending balance	$ (10)	$ (26)	$ (10)	$ (26)