Consolidated Statement of Changes in Shareholders' Equity (Unaudited) - USD ($) shares in Millions, $ in Millions	Total	Common stock [Member]	Retained earnings [Member]	Accumulated other comprehensive income (loss), net of tax [Member]	Treasury stock, at cost [Member]	Common shares outstanding [Member]
Balance, beginning of period at Dec. 31, 2020		$ 23,743	$ 38,771	$ 2,502	$ (35,815)
Shareholders' Equity [Roll Forward]
Employee share-based compensation		108
Compensation amortization under share-based plans and other changes		54
Net income	$ 733		733
Dividends			(216)
Other			(3)
Other comprehensive loss	(1,211)			(1,211)
Treasury stock acquired — share repurchase authorizations					(356)
Net shares acquired related to employee share-based compensation plans					(41)
Balance, end of period at Mar. 31, 2021	28,269	23,905	39,285	1,291	(36,212)
Balance, beginning of year (in shares) at Dec. 31, 2020						252.4
Common shares outstanding
Treasury stock acquired - share repurchase authorizations (in shares)						(2.4)
Net shares issued under employee share-based compensation plans (in shares)						1.5
Balance, end of period (in shares) at Mar. 31, 2021						251.5
Balance, beginning of period at Dec. 31, 2021	28,887	24,154	41,555	1,193	(38,015)
Shareholders' Equity [Roll Forward]
Employee share-based compensation		135
Compensation amortization under share-based plans and other changes		59
Net income	1,018		1,018
Dividends			(214)
Other			0
Other comprehensive loss	(3,795)			(3,795)
Treasury stock acquired — share repurchase authorizations	(500)				(500)
Net shares acquired related to employee share-based compensation plans	(59)				(59)
Balance, end of period at Mar. 31, 2022	$ 25,531	$ 24,348	$ 42,359	$ (2,602)	$ (38,574)
Balance, beginning of year (in shares) at Dec. 31, 2021	241.2					241.2
Common shares outstanding
Treasury stock acquired - share repurchase authorizations (in shares)	(2.9)					(2.9)
Net shares issued under employee share-based compensation plans (in shares)						1.7
Balance, end of period (in shares) at Mar. 31, 2022	240.0					240.0