Commitments and contingencies - Operating and Finance Leases (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Leases
Cash balance maintained to secure a letter of credit associated with a real estate lease	$ 410	$ 425
Operating lease right-of-use assets	4,037	5,673
Finance lease right-of-use assets	0	90
Outstanding operating lease obligations	4,000	5,600
Current operating lease liability	1,558	1,682
Non-current operating lease liability	2,462	3,911
Outstanding finance lease obligations	$ 0	$ 21
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]		Accrued Expenses and Other Current Liabilities.
Weighted average discount rate on operating lease liabilities (as a percent)	1.40%
Weighted average lease term remaining on operating lease liabilities (in years)	3 years
Maximum
Leases
Outstanding finance lease obligations		$ 100