Accumulated Other Comprehensive Loss - Schedule of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 13,903	$ 13,703
Net change	662	(173)
Ending balance	14,232	13,580
Accumulated other comprehensive loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(3,924)	(3,816)
Net change	662	(173)
Ending balance	(3,262)	(3,989)
Available-for-sale securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(3,307)	(3,146)
Net change	642	(171)
Ending balance	(2,665)	(3,317)
Held-to-maturity securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(616)	(682)
Net change	15	15
Ending balance	(601)	(667)
Translation adjustments and net investment hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	20	21
Net change	0	(1)
Ending balance	20	20
Cash flow hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(21)	(9)
Net change	5	(16)
Ending balance	$ (16)	$ (25)