License and Collaboration Agreements - Summary of Revenues by Collaboration and by Category of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
License And Collaboration Agreements [Line Items]
Total collaboration and license revenues	$ 18,005	$ 9,461
Gilead Access Rights
License And Collaboration Agreements [Line Items]
Total collaboration and license revenues	8,316	7,711
License and Development Services for all Gilead Programs
License And Collaboration Agreements [Line Items]
Total collaboration and license revenues	7,939
Taiho Access Rights
License And Collaboration Agreements [Line Items]
Total collaboration and license revenues	$ 1,750	$ 1,750