Income taxes - Schedule of Valuation Allowance - (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Valuation Allowance [Roll Forward]
Balance at January 1	$ 914	$ 737	$ 578
Acquisitions	12	0	0
Provision for income taxes	188	151	203
Foreign currency and other	(55)	26	(44)
Balance at December 31	$ 1,059	$ 914	$ 737