Parent Company Financial Information - Statements of Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Dividend income:
Other income (loss)	$ 75	$ 68	$ 74
Interest on term borrowings	72	72	64
Personnel expense	1,101	1,210	1,033
Income before income taxes	1,159	1,284	933
Income tax benefit	247	274	76
Equity in undistributed net income (loss) of subsidiaries:
Net income attributable to controlling interest	900	999	845
Parent Company
Dividend income:
Bank	435	770	180
Non-bank	16	0	0
Total dividend income	451	770	180
Other income (loss)	22	(26)	0
Total income	473	744	180
Interest on term borrowings	31	31	39
Personnel expense	128	89	54
Total expense	159	120	93
Income before income taxes	314	624	87
Income tax benefit	(31)	(35)	(18)
Income before equity in undistributed net income of subsidiaries	345	659	105
Equity in undistributed net income (loss) of subsidiaries:
Bank	561	332	736
Non-bank	(6)	8	4
Net income attributable to controlling interest	$ 900	$ 999	$ 845