Consolidated Statement of Changes in Shareholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Common stock [Member]	Retained earnings [Member]	Retained earnings [Member] Cumulative Effect, Period of Adoption, Adjustment [Member]	Accumulated other comprehensive income (loss), net of tax [Member]	Treasury stock, at cost [Member]	Common shares outstanding [Member]
Balance, beginning of year at Dec. 31, 2019		$ 23,469	$ 36,977	$ (43)	$ 640	$ (35,143)
Shareholders' Equity [Roll Forward]
Employee share-based compensation		123
Compensation amortization under share-based plans and other changes		151
Net income	$ 2,697		2,697
Dividends			(864)
Other			4
Other comprehensive income (loss)	1,862				1,862
Treasury stock acquired — share repurchase authorization						(625)
Net shares acquired related to employee share-based compensation plans						(47)
Balance, end of year at Dec. 31, 2020	29,201	23,743	38,771		2,502	(35,815)
Balance, beginning of year (in shares) at Dec. 31, 2019							255.5
Common shares outstanding
Treasury stock acquired — share repurchase authorization (in shares)							(4.9)
Net shares issued under employee share-based compensation plans (in shares)							1.8
Balance, end of year (in shares) at Dec. 31, 2020							252.4
Shareholders' Equity [Roll Forward]
Employee share-based compensation		247
Compensation amortization under share-based plans and other changes		164
Net income	3,662		3,662
Dividends			(876)
Other			(2)
Other comprehensive income (loss)	(1,309)				(1,309)
Treasury stock acquired — share repurchase authorization						(2,156)
Net shares acquired related to employee share-based compensation plans	(44)					(44)
Balance, end of year at Dec. 31, 2021	$ 28,887	24,154	41,555		1,193	(38,015)
Common shares outstanding
Treasury stock acquired — share repurchase authorization (in shares)							(13.9)
Net shares issued under employee share-based compensation plans (in shares)							2.7
Balance, end of year (in shares) at Dec. 31, 2021	241.2						241.2
Shareholders' Equity [Roll Forward]
Employee share-based compensation		227
Compensation amortization under share-based plans and other changes		184
Net income	$ 2,842		2,842
Dividends			(880)
Other			(1)
Other comprehensive income (loss)	(7,638)				(7,638)
Treasury stock acquired — share repurchase authorization	(2,000)					(2,000)
Net shares acquired related to employee share-based compensation plans	(61)					(61)
Balance, end of year at Dec. 31, 2022	$ 21,560	$ 24,565	$ 43,516		$ (6,445)	$ (40,076)
Common shares outstanding
Treasury stock acquired — share repurchase authorization (in shares)	(11.6)						(11.6)
Net shares issued under employee share-based compensation plans (in shares)							2.5
Balance, end of year (in shares) at Dec. 31, 2022	232.1						232.1