Income taxes - Narrative (Details) - USD ($) $ in Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Provision for income taxes	$ 231	$ 153	$ 241	$ 384	$ 462
Effective tax rate	21.10%	16.70%	19.00%
Tax reserves	$ 143			143		$ 138
Impact on effective tax rate if tax reserves were unnecessary	143			143
Accrued interest, related to income taxes in the balance sheet	43			43
Additional tax expense related to interest				4	$ 4
Reasonably possible decrease in uncertain tax positions within the next 12 months, if a re-evaluation is required	$ 21			$ 21