Income taxes - Provision for Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Income Tax Disclosure [Abstract]
Taxes calculated using the estimated annual effective tax rate	$ 276	$ 361
Discrete tax items	(38)	(36)
Provision for income taxes	$ 238	$ 325
Effective tax rate	12.00%	13.00%