Consolidated Statements of Changes in Equity - USD ($) $ in Millions		Total	Series D Preferred Stock	Series E Preferred Stock	Series F Preferred Stock	Series G Preferred Stock	Preferred Stock	Preferred Stock Series G Preferred Stock	Common Stock	Capital Surplus	Capital Surplus Series G Preferred Stock	Retained Earnings	Retained Earnings Series D Preferred Stock	Retained Earnings Series E Preferred Stock	Retained Earnings Series F Preferred Stock	Retained Earnings Series G Preferred Stock	Treasury Stock, at Cost	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests	Impact of ASC 326 Adoption	[1]	Impact of ASC 326 Adoption Retained Earnings	[1]
Beginning Balance, Preferred Shares (in shares) at Dec. 31, 2018							946,000
Beginning Balance, Common Shares (in shares) at Dec. 31, 2018									1,019,503,000
Beginning Balance at Dec. 31, 2018		$ 15,596					$ 1,450		$ 1,257	$ 6,331		$ 11,556					$ (4,181)	$ (818)	$ 1
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible List]		Accounting Standards Update 2016-13 [Member]
Net income (loss)		$ 1,717										1,717
Other comprehensive income (loss)		844																844
Deferred compensation		9								9
Dividends, Cash [Abstract]
Cash dividends declared on common shares		(707)										(707)
Cash dividends declared on preferred stock			$ (26)	$ (31)	$ (24)	$ (16)							$ (26)	$ (31)	$ (24)	$ (16)
Issuance of Preferred Stock (in shares)								450,000
Issuance of Preferred Stock						435		$ 450			$ (15)
Open market Common Share repurchases (in shares)									(48,347,000)
Open market Common Share repurchases		(835)															(835)
Employee equity compensation program Common Share repurchases (in shares)									(1,901,000)
Employee equity compensation program Common Share repurchases		(35)								(2)							(33)
Common Shares reissued (returned) for stock options and other employee benefit plans (in shares)									7,934,000
Common shares reissued (returned) for stock options and other employee benefit plans		112								(28)							140
Net contribution from (distribution to) noncontrolling interests		(1)																	(1)
Ending Balance, Preferred Shares (in shares) at Dec. 31, 2019							1,396,000
Ending Balance, Common Shares (in shares) at Dec. 31, 2019									977,189,000
Ending Balance at Dec. 31, 2019		17,038					$ 1,900		$ 1,257	6,295		12,469					(4,909)	26	0	$ (230)		$ (230)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		1,343										1,343
Other reclassification of AOCI		(2)										(2)
Other comprehensive income (loss)		712																712
Deferred compensation		4								4
Dividends, Cash [Abstract]
Cash dividends declared on common shares		(723)										(723)
Cash dividends declared on preferred stock			(26)	(31)	(24)	(25)							(26)	(31)	(24)	(25)
Open market Common Share repurchases (in shares)									(7,151,000)
Open market Common Share repurchases		(134)															(134)
Employee equity compensation program Common Share repurchases (in shares)									(1,823,000)
Employee equity compensation program Common Share repurchases		(54)								(18)							(36)
Common Shares reissued (returned) for stock options and other employee benefit plans (in shares)									7,558,000
Common shares reissued (returned) for stock options and other employee benefit plans		133															133
Ending Balance, Preferred Shares (in shares) at Dec. 31, 2020							1,396,000
Ending Balance, Common Shares (in shares) at Dec. 31, 2020									975,773,000
Ending Balance at Dec. 31, 2020		17,981					$ 1,900		$ 1,257	6,281		12,751					(4,946)	738	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		2,625										2,625							0
Other comprehensive income (loss)		(1,324)																(1,324)
Deferred compensation		9								9
Dividends, Cash [Abstract]
Cash dividends declared on common shares		(717)										(717)
Cash dividends declared on preferred stock			$ (26)	$ (31)	$ (25)	$ (24)							$ (26)	$ (31)	$ (25)	$ (24)
Open market Common Share repurchases (in shares)									(27,346,000)
Open market Common Share repurchases		(559)															(559)
Employee equity compensation program Common Share repurchases (in shares)									(1,611,000)
Employee equity compensation program Common Share repurchases		(32)															(32)
Common Shares reissued (returned) for stock options and other employee benefit plans (in shares)									8,061,000
Common shares reissued (returned) for stock options and other employee benefit plans		131								(12)							143
Common share repurchases under ASR program (in shares)	[2]								(26,027,000)
Common Share repurchases under ASR program (b)	[2]	585															585
Ending Balance, Preferred Shares (in shares) at Dec. 31, 2021			21,000	500,000	425,000	450,000	1,396,000
Ending Balance, Common Shares (in shares) at Dec. 31, 2021									928,850,000
Ending Balance at Dec. 31, 2021		$ 17,423					$ 1,900		$ 1,257	$ 6,278		$ 14,553					$ (5,979)	$ (586)	$ 0

[1] Includes the impact of implementing ASU 2016-13. See Notes to Consolidated Financial Statements.

[2] See Note 24 (“Shareholders' Equity”) for additional detail regarding ASR program.