License and Collaboration Agreements - Summary of Revenues by Collaboration, Category of Revenue and Method of Recognition (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
License And Collaboration Agreements [Line Items]
Total collaboration and license revenues	$ 382,882	$ 77,517	$ 15,000
Gilead License to Domvanalimab
License And Collaboration Agreements [Line Items]
Total collaboration and license revenues	328,838
Gilead License To Zimberelimab
License And Collaboration Agreements [Line Items]
Total collaboration and license revenues		55,096
Development Services for all Gilead Programs
License And Collaboration Agreements [Line Items]
Total collaboration and license revenues	1,135
Gilead Access Rights
License And Collaboration Agreements [Line Items]
Total collaboration and license revenues	30,909	15,421
Taiho License to Domvanalimab
License And Collaboration Agreements [Line Items]
Total collaboration and license revenues	15,000
Taiho License to Zimberelimab
License And Collaboration Agreements [Line Items]
Total collaboration and license revenues			8,000
Taiho Access Rights
License And Collaboration Agreements [Line Items]
Total collaboration and license revenues	$ 7,000	$ 7,000	$ 7,000