Investment Securities - Gains and Losses Recognized in Income from Securities (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Available-for-sale debt and other securities:
Realized gains	$ 16,000,000	$ 34,000,000	$ 47,000,000
Realized losses	(13,000,000)	(19,000,000)	(2,000,000)
Impairment losses	(1,000,000)	(19,000,000)	0
Net realized gains (losses) on available-for-sale debt and other securities	2,000,000	(4,000,000)	45,000,000
Trading debt securities:
Net realized (losses) gains	(2,000,000)	(2,000,000)	2,000,000
Net unrealized gains (losses)	11,000,000	(3,000,000)	0
Net trading debt securities gains (losses)	9,000,000	(5,000,000)	2,000,000
Equity securities:
Net realized gains	1,000,000	7,000,000	10,000,000
Net unrealized (losses) gains	(96,000,000)	(7,000,000)	7,000,000
Net equity securities (losses) gains	(95,000,000)	0	17,000,000
Total (losses) gains recognized in income from available-for-sale debt and other securities, trading debt securities and equity securities	(84,000,000)	(9,000,000)	64,000,000
Commercial Banking Revenue and Wealth and Asset Management Revenue
Equity securities:
Securities gains (losses)	$ 0	$ (7,000,000)	$ 5,000,000