Stock-based compensation - Allocated Share-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Share-based Payment Arrangement, Expensed
Stock-based compensation	$ 4,247	$ 1,442	$ 8,026	$ 3,593
Research and development
Share-based Payment Arrangement, Expensed
Stock-based compensation	1,697	851	3,120	1,927
Selling, general and administrative
Share-based Payment Arrangement, Expensed
Stock-based compensation	$ 2,550	$ 591	$ 4,906	$ 1,666