Commitments - License agreements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
License Agreement, Upfront Payments
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development expense	$ 3,075	$ 250	$ 750
License Agreement, Milestone Payments
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Research and development expense	$ 2,125	$ 750	$ 600