Consolidated Statement of Comprehensive (Loss) Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Statement of Comprehensive Income [Abstract]
Net income	$ 1,020	$ 1,714	$ 3,060
Available-for-sale securities
Net unrealized gains (losses) arising during the period	260	(3,982)	(656)
Net unrealized loss on securities transferred to held-to-maturity	693	0	0
Less: Net realized gains reclassified to net income	4	18	79
Net change	949	(4,000)	(735)
Held-to-maturity securities
Net unrealized loss on securities transferred from available-for-sale	(693)	0	0
Less: Amortization of amounts previously recorded upon transfer from available-for-sale	(11)	0	0
Net change	(682)	0	0
Translation adjustments
Net unrealized gains (losses) arising during the period	5	(8)	0
Net investment hedges
Net unrealized (losses) gains arising during the period	(2)	7	0
Translation adjustments and net investment hedges, net change	3	(1)	0
Cash flow hedges
Net unrealized losses arising during the period	(16)	(2)	0
Less: Net realized gains reclassified to net income	11	15	47
Net change	(27)	(17)	(47)
Defined benefit pension plans
Net unrealized gains (losses) arising during the period	0	2	(8)
Less: Net realized losses reclassified to net income	0	(115)	(1)
Net change	0	117	(7)
Other comprehensive income (loss), net of tax	243	(3,901)	(789)
Comprehensive income (loss)	$ 1,263	$ (2,187)	$ 2,271