Accumulated Other Comprehensive Loss - Schedule of Reclassification Out of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss), before tax	$ (26)	$ (115)	$ (252)	$ 256
Other comprehensive income (loss), tax effect	6	28	59	(60)
Other comprehensive income (loss), net of tax	(20)	(87)	(193)	196
Available-for-sale securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized gains (losses) arising during the period, before tax			(270)	286
Net unrealized gains (losses) arising during the period, tax			64	(68)
Net unrealized gains (losses) arising during the period, net of tax			(206)	218
Reclassification from AOCI, before tax			1	5
Reclassification from AOCI, tax			0	(1)
Reclassification from AOCI, net of tax			1	4
Other comprehensive income (loss), before tax	(47)	(91)	(271)	281
Other comprehensive income (loss), tax effect	11	21	64	(67)
Other comprehensive income (loss), net of tax	(36)	(70)	(207)	214
Held-to-maturity securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from AOCI, before tax	(22)		(42)
Reclassification from AOCI, tax	5		10
Reclassification from AOCI, net of tax	(17)		(32)
Translation adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss), before tax	(2)	6	(7)	6
Other comprehensive income (loss), tax effect	0	(1)	1	(1)
Other comprehensive income (loss), net of tax	(2)	5	(6)	5
Net investment hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other comprehensive income (loss), before tax	2	(3)	6	(3)
Other comprehensive income (loss), tax effect	0	1	(1)	1
Other comprehensive income (loss), net of tax	2	(2)	5	(2)
Cash flow hedges
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net unrealized gains (losses) arising during the period, before tax	(3)	(22)	(25)	(18)
Net unrealized gains (losses) arising during the period, tax	1	6	6	5
Net unrealized gains (losses) arising during the period, net of tax	(2)	(16)	(19)	(13)
Reclassification from AOCI, before tax	(2)	5	(3)	10
Reclassification from AOCI, tax	1	(1)	1	(2)
Reclassification from AOCI, net of tax	(1)	4	(2)	8
Other comprehensive income (loss), before tax	(1)	(27)	(22)	(28)
Other comprehensive income (loss), tax effect	0	7	5	7
Other comprehensive income (loss), net of tax	$ (1)	$ (20)	$ (17)	$ (21)