Significant accounting policies - Grant revenue (Details) - USD ($) $ in Thousands		12 Months Ended
	Sep. 29, 2020	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Total revenue		$ 110,556	$ 86,377	$ 56,734
Research and Development Expense		27,978	20,174	$ 16,190
RADx WP2
Total revenue		17,700
Contract value	$ 18,200
Research and Development Expense		3,400	2,600
Grant revenue
Total revenue		5,217	6,422
Grant revenue | RADx WP2
Total revenue		9,576	4,362
Contract value		$ 18,200	$ 18,200