Income taxes - Summary of Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Current:
Federal	$ 0	$ 0	$ 0
State	53	0	0
Foreign	0	0	0
Total current provision	53	0	0
Deferred:
Federal	0	0	0
State	0	0	0
Foreign	0	0	0
Total deferred provision	$ 0	$ 0	$ 0