Income taxes - Schedule of Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Current:
U.S.	$ 65	$ (11,898)	$ (6,143)
Non-U.S.	6,211	10,192	4,405
Total current	6,276	(1,706)	(1,738)
Deferred:
Non-U.S.	0	0	144
Total deferred	0	0	144
Total income tax provision	$ 6,276	$ (1,706)	$ (1,594)