Right of use of assets - Summary of costs included in operating expenses related to right of use assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Lease cost
Operating lease cost	$ 560	$ 269
Variable lease cost	0	(45)
Short-term lease cost	86	86
Total lease cost	646	310
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows used in operating leases	$ 578	$ 269
Weighted average remaining lease term (in years)	11 months 1 day	9 months
Weighted average discount rate (in percent)	4.67%	5.00%