Income taxes - Provision for Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Income Tax Disclosure [Abstract]
Taxes calculated using the estimated annual effective tax rate	$ 166	$ 176
Discrete tax items	(69)	12
Provision for income taxes	$ 97	$ 188
Effective tax rate	8.00%	15.00%