Consolidated Statement of Changes in Shareholders' Equity - USD ($) $ 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)							150,723,000
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			503,880,000
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)							6,233,000
Common stock awards exercised	71			22			$ 49
Common stock awards exercised (in shares)							(1,111,000)
Other	2				2
Other (shares)							2,000
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			503,880,000
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			503,880,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,996
Other comprehensive income (loss)	(869)
Cash dividends declared:
Common stock dividends	(570)
Preferred stock cash dividend	(79)
Ending balance at Sep. 30, 2021	$ 27,314	1,976	$ 504	10,763	24,785	(682)	$ (10,032)
Ending balance (shares) at Sep. 30, 2021			503,880,000				138,250,000
Cash dividends declared:
Cash dividends declared (in USD per share)	$ 1.61
Treasury stock (shares)							155,847,000
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			503,880,000
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)							5,017,000
Common stock awards exercised	42			19			$ 23
Common stock awards exercised (in shares)							(487,000)
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			503,880,000
Cash dividends declared:
Cash dividends declared (in USD per share)	$ 0.52
Treasury stock (shares)							160,377,000
Net income	$ 714				714
Other comprehensive income (loss)	(260)					(260)
Common stock dividends	(209)				(209)
Preferred stock cash dividend	(20)				(20)
Common stock acquired	0
Common stock acquired (shares)
Common stock awards exercised	28			8			$ 20
Common stock awards exercised (in shares)							(399,000)
Other	(6)			(7)			$ 1
Other (shares)							(4,000)
Ending balance at Sep. 30, 2021	$ 27,314	1,976	$ 504	10,763	24,785	(682)	$ (10,032)
Ending balance (shares) at Sep. 30, 2021			503,880,000				138,250,000
Cash dividends declared:
Cash dividends declared (in USD per share)	$ 0.57
Common stock issued	$ 1,900			516			$ 1,384
Stock issued during period, shares, new issues							(21,724,000)
Treasury stock (shares)							137,897,000
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			503,880,000
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)							(1,132,000)
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			503,880,000
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			503,880,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	2,041
Other comprehensive income (loss)	(3,135)
Cash dividends declared:
Common stock dividends	(651)
Preferred stock cash dividend	(76)
Ending balance at Sep. 30, 2022	$ 25,648	1,976	$ 504	10,760	26,552	(4,268)	$ (9,876)
Ending balance (shares) at Sep. 30, 2022			503,880,000				135,912,000
Cash dividends declared:
Cash dividends declared (in USD per share)	$ 1.77
Treasury stock (shares)							136,765,000
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			503,880,000
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)							(505,000)
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			503,880,000
Cash dividends declared:
Cash dividends declared (in USD per share)	$ 0.57
Treasury stock (shares)							136,260,000
Net income	$ 690				690
Other comprehensive income (loss)	(581)					(581)
Common stock dividends	(232)				(232)
Preferred stock cash dividend	(21)				(21)
Common stock awards exercised	25			3			$ 22
Common stock awards exercised (in shares)							(348,000)
Ending balance at Sep. 30, 2022	$ 25,648	$ 1,976	$ 504	$ 10,760	$ 26,552	$ (4,268)	$ (9,876)
Ending balance (shares) at Sep. 30, 2022			503,880,000				135,912,000
Cash dividends declared:
Cash dividends declared (in USD per share)	$ 0.63