Revenue (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Revenue
Revenue, contract liabilities	$ 0			$ 3,400
Revenues	153	$ 668		4,317	$ 3,633
Contract assets	0			0		$ 0
Contract liability	601			601		$ 3,386
Product development and licensing agreements
Revenue
Revenues		12		29	2,297
Contracts and grants
Revenue
Revenues	153	656		4,288	1,336
Rockefeller | Product development and licensing agreements
Revenue
Revenue, contract liabilities			$ 1,800
Rockefeller University and Duke University | Contracts and grants
Revenue
Revenues	100	300		4,000	900
National Institute of Health
Revenue
Revenues	$ 0	$ 300		$ 300	$ 300