Sponsored Research and License Agreements - Additional Information (Details) $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended
	May 31, 2020 USD ($) Installment	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2019 USD ($)
Sponsored Research And License Agreements [Line Items]
Research and development expense		$ 8,885	$ 2,755	$ 15,724	$ 3,906
SRA-2 | BCM
Sponsored Research And License Agreements [Line Items]
Research activities performing fees	$ 1,000
Number of installment for research activities payments | Installment	4
Agreement for research activities, additional term with written consent	1 year
Agreement for research activities, term	1 year
License Agreement Amendment | BCM
Sponsored Research And License Agreements [Line Items]
Non-refundable license fee payments	$ 300
Milestone payments				$ 40,000
Minimum percentage of eligible to receive tiered royalties		1.00%		1.00%
Collective Agreements | BCM
Sponsored Research And License Agreements [Line Items]
Research and development expense		$ 500	$ 300	$ 800	$ 400