Income taxes (Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021	Apr. 28, 2022	May 31, 2021
Income Tax Examination [Line Items]
Effective income tax rate	10.40%			12.60%			11.80%	12.60%
Increase in unrecognized tax benefits resulting from tax positions taken during the current period	$ 25						$ 120
Stock repurchased	$ 900	$ 0	$ 5,410	$ 1,069	$ 1,592	$ 865	$ 6,310	$ 3,526
Domestic Tax Authority
Income Tax Examination [Line Items]
Proposed additional income tax										$ 3,600
Repatriation tax on proposed additional tax										$ 900
Proposed additional income tax 2013-2015									$ 5,100
Penalties on proposed additional income tax 2013-2015									2,000
Repatriation tax on proposed additional tax 2013-2015									$ 2,200