Revenue recognition - Summarizes the activity under WP2 (Details) - USD ($)		3 Months Ended		12 Months Ended
	Sep. 29, 2020	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Disaggregation of Revenue [Line Items]
Total revenue		$ 29,552,000	$ 27,209,000
Grant revenue
Disaggregation of Revenue [Line Items]
Total revenue		0	$ 2,291,000
RADx WP2
Disaggregation of Revenue [Line Items]
Total WP2 grant amount	$ 18,200,000
RADx WP2 | Grant revenue
Disaggregation of Revenue [Line Items]
Total revenue		9,576,000		$ 9,576,000
Proceeds used for assets		8,624,000		8,104,000
Total recognized		18,200,000		17,680,000
Amount accrued		(520,000)
Total cash received		17,680,000		17,680,000
Proceeds received		17,680,000		17,680,000
Proceeds reasonably assured		520,000		520,000
Total WP2 grant amount		$ 18,200,000		$ 18,200,000