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, 2021		$ 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 comprehensive income (loss)	(3,795)			(3,795)
Treasury stock acquired — share repurchase authorizations					(500)
Net shares acquired related to employee share-based compensation plans					(59)
Balance, end of period at Mar. 31, 2022	25,531	24,348	42,359	(2,602)	(38,574)
Balance, beginning of period (in shares) at Dec. 31, 2021						241.2
Common shares outstanding
Treasury stock acquired - share repurchase authorizations (in shares)						(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
Balance, beginning of period at Dec. 31, 2022	21,560	24,565	43,516	(6,445)	(40,076)
Shareholders' Equity [Roll Forward]
Employee share-based compensation		68
Compensation amortization under share-based plans and other changes		70
Net income	975		975
Dividends			(218)
Other comprehensive income (loss)	1,059			1,059
Treasury stock acquired — share repurchase authorizations	(400)				(400)
Net shares acquired related to employee share-based compensation plans	(62)				(62)
Balance, end of period at Mar. 31, 2023	$ 23,052	$ 24,703	$ 44,273	$ (5,386)	$ (40,538)
Balance, beginning of period (in shares) at Dec. 31, 2022	232.1					232.1
Common shares outstanding
Treasury stock acquired - share repurchase authorizations (in shares)	(2.2)					(2.2)
Net shares issued under employee share-based compensation plans (in shares)						1.1
Balance, end of period (in shares) at Mar. 31, 2023	231.0					231.0