Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Millions	Total	Cumulative Effect, Period of Adoption, Adjustment	Preferred stock	Common stock shares (in thousands)	Accumulated paid-in capital	Retained earnings	Retained earnings Cumulative Effect, Period of Adoption, Adjustment	Accumulated other comprehensive income (loss)
Beginning balance at Dec. 31, 2020	$ 7,886		$ 566		$ 2,686	$ 4,309		$ 325
Beginning balance (in shares) at Dec. 31, 2020				164,090,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,129					1,129
Other comprehensive income (loss), net of tax	(405)							(405)
Bank common stock repurchased (in shares)				(13,521,000)
Bank common stock repurchased	(800)				(800)
Preferred stock redemption (in shares)			(126,000,000)
Preferred stock redemption	(126)				3	(3)
Net activity under employee plans and related tax benefits (in shares)				1,056,000
Net activity under employee plans and related tax benefits	39				39
Dividends on preferred stock	(29)					(29)
Dividends on common stock	(232)					(232)
Change in deferred compensation	1					1
Ending balance at Dec. 31, 2021	7,463		$ 440		1,928	5,175		(80)
Ending balance (in shares) at Dec. 31, 2021				151,625,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 907					907
Cumulative effect adjustment, adoption of ASU 2022-02, Financial Instruments - Credit Losses: Troubled Debt Restructurings	Accounting Standards Update 2022-02 [Member]
Other comprehensive income (loss), net of tax	$ (3,032)							(3,032)
Bank common stock repurchased (in shares)	(3,600,000)			(3,581,000)
Bank common stock repurchased	$ (202)				(202)
Net activity under employee plans and related tax benefits (in shares)				620,000
Net activity under employee plans and related tax benefits	28				28
Dividends on preferred stock	(29)					(29)
Dividends on common stock	(240)					(240)
Change in deferred compensation	(2)					(2)
Ending balance at Dec. 31, 2022	$ 4,893	$ 2	440		1,754	5,811	$ 2	(3,112)
Ending balance (in shares) at Dec. 31, 2022	148,664,000			148,664,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 680					680
Other comprehensive income (loss), net of tax	420							420
Bank common stock repurchased (in shares)				(972,000)
Bank common stock repurchased	(51)				(51)
Net activity under employee plans and related tax benefits (in shares)				461,000
Net activity under employee plans and related tax benefits	28				28
Dividends on preferred stock	(32)					(32)
Dividends on common stock	(245)					(245)
Change in deferred compensation	(4)					(4)
Ending balance at Dec. 31, 2023	$ 5,691		$ 440		$ 1,731	$ 6,212		$ (2,692)
Ending balance (in shares) at Dec. 31, 2023	148,153,000			148,153,000