Revenues - Summary of Revenues by Collaboration, Category of Revenue and Method of Recognition (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
License And Collaboration Agreements [Line Items]
Total revenues	$ 25	$ 18
Gilead Collaboration, License and R&D services
License And Collaboration Agreements [Line Items]
Total revenues	17	8
Gilead Collaboration, Access Rights
License And Collaboration Agreements [Line Items]
Total revenues	$ 8	8
Taiho Collaboration, Access Rights
License And Collaboration Agreements [Line Items]
Total revenues		$ 2