Income taxes (Income Before Income Taxes) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Income Tax Examination [Line Items]
Income before income taxes	$ 7,346	$ 6,701	$ 8,133
Domestic [Member]
Income Tax Examination [Line Items]
Income before income taxes	3,026	1,850	4,087
Foreign [Member]
Income Tax Examination [Line Items]
Income before income taxes	$ 4,320	$ 4,851	$ 4,046