License and patent agreements - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
University Of Washington
License and patent agreements [Line Items]
License arrangements, amounts of development milestones payment	$ 0.9
License arrangements, amounts payable based on net sales	$ 10.0
Common stock
License and patent agreements [Line Items]
Shares issued for service (in shares)		12,647
Stock issued for acquisition (in shares)		4,589,771
License and maintenance | University Of Washington
License and patent agreements [Line Items]
Shares issued for service (in shares)	536,813
License and maintenance | Common stock | University Of Washington
License and patent agreements [Line Items]
Stock issued for acquisition (in shares)	188,974
License and maintenance | Minimum | University Of Washington
License and patent agreements [Line Items]
Revenue from contract with customer, excluding assessed tax	$ 100.0
License and maintenance | Maximum | University Of Washington
License and patent agreements [Line Items]
Revenue from contract with customer, excluding assessed tax	$ 1,000.0
Non-voting convertible preferred stock
License and patent agreements [Line Items]
Stock issued for acquisition (in shares)		102,000
Non-voting convertible preferred stock | License and maintenance | University Of Washington
License and patent agreements [Line Items]
Stock issued for acquisition (in shares)	4,197