Income taxes - Provision (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Current:
Federal	$ (6)	$ 0	$ (551)
State	154	217	(73)
Foreign	1,894	638	987
Total current expense	2,042	855	363
Deferred:
Federal	(268)	(487)	(10,657)
State	(170)	(1,145)	(1,173)
Foreign	(2,517)	(4,012)	1,512
Total deferred benefit	(2,955)	(5,644)	(10,318)
Total income tax benefit	$ (913)	$ (4,789)	$ (9,955)