Parent Company Condensed Financial Information (Condensed Statement of Comprehensive Income) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Net financing revenue and other interest income		$ 6,167	$ 4,703	$ 4,633
Total other revenue		2,039	1,983	1,761
Total net revenue		8,206	6,686	6,394
Provision for credit losses		241	1,439	998
Total noninterest expense		4,110	3,833	3,429
Income (loss) from continuing operations before income tax benefit and undistributed income of subsidiaries		3,855	1,414	1,967
Income tax expense from continuing operations		790	328	246
Net income from continuing operations	[1]	3,065	1,086	1,721
Loss from discontinued operations, net of tax	[1]	(5)	(1)	(6)
Net income		3,060	1,085	1,715
Other comprehensive (loss) income, net of tax		(789)	508	654
Comprehensive income		2,271	1,593	2,369
Parent company
Net financing revenue and other interest income		(1,070)	(1,049)	(1,116)
Dividends from bank subsidiaries		3,450	1,150	1,950
Dividends from nonbank subsidiaries		27	66	436
Total other revenue		243	367	343
Total net revenue		2,650	534	1,613
Provision for credit losses		(106)	(68)	35
Total noninterest expense		650	693	626
Income (loss) from continuing operations before income tax benefit and undistributed income of subsidiaries		2,106	(91)	952
Income tax expense from continuing operations		(412)	(300)	(566)
Net income from continuing operations		2,518	209	1,518
Loss from discontinued operations, net of tax		(5)	(1)	(6)
Undistributed income of subsidiaries		547	877	203
Net income		3,060	1,085	1,715
Other comprehensive (loss) income, net of tax		(789)	508	654
Comprehensive income		$ 2,271	$ 1,593	$ 2,369

[1] Figures in the table may not recalculate exactly due to rounding. Earnings per share is calculated based on unrounded numbers.