Consolidated Statements of Changes in Shareholders' Equity (Unaudited) - USD ($) $ in Millions	Total	Class A Common Stock	Class B Common Stock	Series A Preferred Stock	Series B Preferred Stock	Series C Preferred Stock	Preferred Stock	Preferred Stock Series B Preferred Stock	Preferred Stock Series C Preferred Stock	Common Stock Class A Common Stock	Common Stock Class B Common Stock	Additional Paid in Capital	Retained Earnings	Retained Earnings Class A Common Stock	Retained Earnings Class B Common Stock	Retained Earnings Series A Preferred Stock	Retained Earnings Series B Preferred Stock	Retained Earnings Series C Preferred Stock	Accumulated Other Comprehensive (Loss) Income
Beginning balance, shareholders' equity at Dec. 31, 2020	$ 4,229						$ 340			$ 9	$ 1	$ 0	$ 3,867						$ 12
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	424												424
Other comprehensive loss, net of tax	(44)																		(44)
Cash dividends declared		$ (12)	$ (1)											$ (12)	$ (1)
Preferred stock dividends declared	(14)												(14)
Ending balance, shareholders' equity at Sep. 30, 2021	4,582						340			9	1	0	4,264						(32)
Beginning balance, shareholders' equity at Jun. 30, 2021	4,477						340			9	1	0	4,149						(22)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	124												124
Other comprehensive loss, net of tax	(10)																		(10)
Cash dividends declared		(4)	0											(4)	0
Preferred stock dividends declared	(5)												(5)
Ending balance, shareholders' equity at Sep. 30, 2021	4,582						340			9	1	0	4,264						(32)
Beginning balance, shareholders' equity at Dec. 31, 2021	4,738						340			9	1	0	4,378						10
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	841												841
Other comprehensive loss, net of tax	(739)																		(739)
Issued in CIT Merger:	5,279				$ 334	$ 207		$ 334	$ 207	6		5,273
Stock based compensation	74											74
Repurchased 1,027,414 shares of Class A common stock	(842)									(1)		(841)
Cash dividends declared		(21)	(2)											(21)	(2)
Preferred stock dividends declared				$ (14)	(14)	(8)										$ (14)	$ (14)	$ (8)
Ending balance, shareholders' equity at Sep. 30, 2022	9,833						881			14	1	4,506	5,160						(729)
Beginning balance, shareholders' equity at Jun. 30, 2022	10,642						881			15	1	5,345	4,865						(465)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	315												315
Other comprehensive loss, net of tax	(264)																		(264)
Stock based compensation	2											2
Repurchased 1,027,414 shares of Class A common stock	(842)									(1)		(841)
Cash dividends declared		$ (7)	$ (1)											$ (7)	$ (1)
Preferred stock dividends declared				$ (5)	$ (5)	$ (2)										$ (5)	$ (5)	$ (2)
Ending balance, shareholders' equity at Sep. 30, 2022	$ 9,833						$ 881			$ 14	$ 1	$ 4,506	$ 5,160						$ (729)