Condensed Consolidated Statement of Changes in Equity - USD ($) $ in Millions	Total	Series B Preferred Stock	Series C Preferred Stock	Cumulative Effect, Period of Adoption, Adjustment	Cumulative Effect, Period of Adoption, Adjusted Balance	Common stock and paid-in capital	Common stock and paid-in capital Cumulative Effect, Period of Adoption, Adjusted Balance	Preferred stock	Preferred stock Series B Preferred Stock	Preferred stock Series C Preferred Stock	Preferred stock Cumulative Effect, Period of Adoption, Adjusted Balance	Accumulated deficit	Accumulated deficit Series B Preferred Stock	Accumulated deficit Series C Preferred Stock	Accumulated deficit Cumulative Effect, Period of Adoption, Adjustment	Accumulated deficit Cumulative Effect, Period of Adoption, Adjusted Balance	Accumulated other comprehensive (loss) income	Accumulated other comprehensive (loss) income Cumulative Effect, Period of Adoption, Adjustment	Accumulated other comprehensive (loss) income Cumulative Effect, Period of Adoption, Adjusted Balance	Treasury stock	Treasury stock Cumulative Effect, Period of Adoption, Adjusted Balance
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adoption of Accounting Standards Update 2016-13	$ 13,268			$ (2)	$ 13,266	$ 21,345	$ 21,345					$ (5,489)			$ (10)	$ (5,499)	$ (539)	$ 8	$ (531)	$ (2,049)	$ (2,049)
Beginning balance at Dec. 31, 2018	$ 13,268			(2)	13,266	21,345	21,345					(5,489)			(10)	(5,499)	(539)	$ 8	(531)	(2,049)	(2,049)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible Enumeration]	Accounting Standards Update 2016-13
Net income	$ 1,715											1,715
Share-based compensation	93					93
Other comprehensive income (loss)	654																654
Common stock repurchases	(1,039)																			(1,039)
Common stock dividends	(273)											(273)
Ending balance at Dec. 31, 2019	14,416			(1,017)	13,399	21,438	21,438	$ 0			$ 0	(4,057)			(1,017)	(5,074)	123		123	(3,088)	(3,088)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adoption of Accounting Standards Update 2016-13	14,416			$ (1,017)	$ 13,399	21,438	$ 21,438	0			$ 0	(4,057)			$ (1,017)	$ (5,074)	123		$ 123	(3,088)	$ (3,088)
Net income	1,085											1,085
Share-based compensation	106					106
Other comprehensive income (loss)	508																508
Common stock repurchases	(106)																			(106)
Common stock dividends	(289)											(289)
Ending balance at Dec. 31, 2020	14,703					21,544		0				(4,278)					631			(3,194)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adoption of Accounting Standards Update 2016-13	14,703					21,544		0				(4,278)					631			(3,194)
Net income	3,060											3,060
Share-based compensation	127					127
Other comprehensive income (loss)	(789)																(789)
Common stock repurchases	(1,994)																			(1,994)
Common stock dividends	(324)											(324)
Net proceeds from issuance of series preferred stock		$ 1,335	$ 989						$ 1,335	$ 989
Preferred stock dividends		$ (36)	$ (21)										$ (36)	$ (21)
Ending balance at Dec. 31, 2021	17,050					21,671		2,324				(1,599)					(158)			(5,188)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adoption of Accounting Standards Update 2016-13	$ 17,050					$ 21,671		$ 2,324				$ (1,599)					$ (158)			$ (5,188)