Consolidated Statement of Changes in Shareholders' Equity - USD ($) shares in Thousands, $ in Millions	Total	Preferred Stock	Common Stock	Surplus	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Treasury stock (shares)							150,723
Beginning balance at Dec. 31, 2020	$ 26,200	$ 2,471	$ 504	$ 10,205	$ 23,442	$ 187	$ (10,609)
Beginning balance (shares) at Dec. 31, 2020			503,880
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	519				519
Other comprehensive income (loss)	(605)					(605)
Preferred stock redeemed	(500)	(495)			(5)
Cash dividends declared:
Common stock dividends	(182)				(182)
Preferred stock cash dividend	(25)				(25)
Common stock acquired	(475)						$ (475)
Common stock acquired (shares)							6,233
Common stock awards exercised	71			22			$ 49
Common stock awards exercised (in shares)							(1,111)
Other	2				2
Other (shares)							2
Ending balance at Mar. 31, 2021	$ 25,005	1,976	$ 504	10,227	23,751	(418)	$ (11,035)
Ending balance (shares) at Mar. 31, 2021			503,880
Cash dividends declared:
Cash dividends declared (in USD per share)	$ 0.52
Beginning balance at Dec. 31, 2020	$ 26,200	2,471	$ 504	10,205	23,442	187	(10,609)
Beginning balance (shares) at Dec. 31, 2020			503,880
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,282
Other comprehensive income (loss)	(609)
Cash dividends declared:
Common stock dividends	(361)
Preferred stock cash dividend	(59)
Ending balance at Jun. 30, 2021	$ 25,167	1,976	$ 504	10,246	24,300	(422)	$ (11,437)
Ending balance (shares) at Jun. 30, 2021			503,880
Cash dividends declared:
Cash dividends declared (in USD per share)	$ 1.04
Treasury stock (shares)							155,847
Beginning balance at Mar. 31, 2021	$ 25,005	1,976	$ 504	10,227	23,751	(418)	$ (11,035)
Beginning balance (shares) at Mar. 31, 2021			503,880
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	763				763
Other comprehensive income (loss)	(4)					(4)
Cash dividends declared:
Common stock dividends	(179)				(179)
Preferred stock cash dividend	(34)				(34)
Common stock acquired	(425)						$ (425)
Common stock acquired (shares)							5,017
Common stock awards exercised	42			19			$ 23
Common stock awards exercised (in shares)							(487)
Other	(1)				(1)
Ending balance at Jun. 30, 2021	$ 25,167	1,976	$ 504	10,246	24,300	(422)	$ (11,437)
Ending balance (shares) at Jun. 30, 2021			503,880
Cash dividends declared:
Cash dividends declared (in USD per share)	$ 0.52
Treasury stock (shares)							160,377
Treasury stock (shares)							137,897
Beginning balance at Dec. 31, 2021	$ 27,363	1,976	$ 504	10,787	25,238	(1,133)	$ (10,009)
Beginning balance (shares) at Dec. 31, 2021			503,880
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	604				604
Other comprehensive income (loss)	(1,565)					(1,565)
Cash dividends declared:
Common stock dividends	(209)				(209)
Preferred stock cash dividend	(20)				(20)
Common stock awards exercised	66			11			$ 77
Common stock awards exercised (in shares)							(1,132)
Other	(15)			(14)	(1)
Other (shares)							0
Ending balance at Mar. 31, 2022	$ 26,224	1,976	$ 504	10,762	25,612	(2,698)	$ (9,932)
Ending balance (shares) at Mar. 31, 2022			503,880
Cash dividends declared:
Cash dividends declared (in USD per share)	$ 0.57
Beginning balance at Dec. 31, 2021	$ 27,363	1,976	$ 504	10,787	25,238	(1,133)	(10,009)
Beginning balance (shares) at Dec. 31, 2021			503,880
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,351
Other comprehensive income (loss)	(2,554)
Cash dividends declared:
Common stock dividends	(419)
Preferred stock cash dividend	(55)
Ending balance at Jun. 30, 2022	$ 25,767	1,976	$ 504	10,757	26,115	(3,687)	$ (9,898)
Ending balance (shares) at Jun. 30, 2022			503,880
Cash dividends declared:
Cash dividends declared (in USD per share)	$ 1.14
Treasury stock (shares)							136,765
Beginning balance at Mar. 31, 2022	$ 26,224	1,976	$ 504	10,762	25,612	(2,698)	$ (9,932)
Beginning balance (shares) at Mar. 31, 2022			503,880
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	747				747
Other comprehensive income (loss)	(989)					(989)
Cash dividends declared:
Common stock dividends	(210)				(210)
Preferred stock cash dividend	(35)				(35)
Common stock awards exercised	29			5			$ 34
Common stock awards exercised (in shares)							(505)
Other	1				1
Ending balance at Jun. 30, 2022	$ 25,767	$ 1,976	$ 504	$ 10,757	$ 26,115	$ (3,687)	$ (9,898)
Ending balance (shares) at Jun. 30, 2022			503,880
Cash dividends declared:
Cash dividends declared (in USD per share)	$ 0.57
Treasury stock (shares)							136,260