Income taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
(Decreases) increases in taxes resulting from:
Taxes at U.S. statutory rate	$ 1,723	$ 839	$ 1,641
Taxes at U. S. statutory rate (as a percent)	21.00%	21.00%	21.00%
Non-U.S. subsidiaries taxed at other than the U.S. rate	$ 211	$ 285	$ 365
Non-U.S. subsidiaries taxed at other than the U.S. rate (as a percent)	2.60%	7.10%	4.70%
State and local taxes, net of federal	$ 28	$ 32	$ 59
State and local taxes, net of federal (as a percent)	0.30%	0.80%	0.80%
Interest and penalties, net of tax	$ 45	$ 28	$ 34
Interest and penalties, net of tax (as a percent)	0.60%	0.70%	0.40%
U.S. tax incentives	$ (123)	$ (52)	$ (149)
U.S. tax incentives (as a percent)	(1.50%)	(1.30%)	(1.90%)
Net excess tax benefits from stock-based compensation	$ (63)	$ (49)	$ (41)
Net excess tax benefits from stock-based compensation, percent	(0.80%)	(1.20%)	(0.50%)
Prior year tax adjustments	$ (36)	$ (80)	$ (178)
Prior year adjustments (as a percent)	(0.40%)	(2.00%)	(2.30%)
Other-net	$ (43)	$ 3	$ 15
Other-net (as a percent)	(0.60%)	0.10%	0.20%
Provision (benefit) for income taxes	$ 1,742	$ 1,006	$ 1,746
Provision (benefit) for income taxes (as a percent)	21.20%	25.20%	22.40%