Accumulated Other Comprehensive Loss - Schedule of Reclassification Out of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss), before tax	$ 868	$ (226)
Other comprehensive income (loss), tax effect	(206)	53
Other comprehensive (loss) income, net of tax	662	(173)
Available-for-sale securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized gains (losses) arising during the period, before tax	346	(223)
Net unrealized gains (losses) arising during the period, tax	(81)	53
Net unrealized gains (losses) arising during the period, net of tax	265	(170)
Reclassification from AOCI, before tax	(495)	1
Reclassification from AOCI, tax	118	0
Reclassification from AOCI, net of tax	(377)	1
Other comprehensive income (loss), before tax	841	(224)
Other comprehensive income (loss), tax effect	(199)	53
Other comprehensive (loss) income, net of tax	642	(171)
Held-to-maturity securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from AOCI, before tax	(20)	(20)
Reclassification from AOCI, tax	5	5
Reclassification from AOCI, net of tax	(15)	(15)
Other comprehensive (loss) income, net of tax	15	15
Translation adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss), before tax		(5)
Other comprehensive income (loss), tax effect		1
Other comprehensive (loss) income, net of tax		(4)
Net investment hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss), before tax		4
Other comprehensive income (loss), tax effect		(1)
Other comprehensive (loss) income, net of tax		3
Cash flow hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized gains (losses) arising during the period, before tax		(22)
Net unrealized gains (losses) arising during the period, tax		5
Net unrealized gains (losses) arising during the period, net of tax		(17)
Reclassification from AOCI, before tax	(7)	(1)
Reclassification from AOCI, tax	2	0
Reclassification from AOCI, net of tax	(5)	(1)
Other comprehensive income (loss), before tax	7	(21)
Other comprehensive income (loss), tax effect	(2)	5
Other comprehensive (loss) income, net of tax	$ 5	$ (16)