Employee benefit plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
U.S.
Defined Contribution Plan Disclosure [Line Items]
Employer contribution, as a percent	3.00%
Contributions	$ 4.1	$ 3.2	$ 2.5
Foreign Plan
Defined Contribution Plan Disclosure [Line Items]
Contributions	$ 1.5	$ 0.4	$ 0.3