License and Collaborations - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2017	Jul. 13, 2020
License And Collaboration Agreements [Line Items]
Liablities classified as noncurrent	$ 140,000,000	$ 122,000,000
Total collaboration and license revenues	112,000,000	383,000,000	$ 78,000,000
AstraZeneca Agreement
License And Collaboration Agreements [Line Items]
Development cost recorded within research and development expenses	4,000,000	1,000,000
Liablities classified as noncurrent	5,000,000	1,000,000
Gilead Collaboration Agreement
License And Collaboration Agreements [Line Items]
Total collaboration and license revenues	4,000,000
Gilead
License And Collaboration Agreements [Line Items]
Receivable from collaboration partners	4,000,000
Gilead | Gilead Collaboration Agreement
License And Collaboration Agreements [Line Items]
Contingent milestone payments receivable					$ 300,000,000
Total collaboration and license revenues	34,000,000	0
Gilead | Gilead Collaboration Agreement | Other Noncurrent Assets
License And Collaboration Agreements [Line Items]
Receivable from collaboration partners- noncurrent	$ 2,000,000
Taiho Pharmaceutical Co., Ltd | Taiho Agreement
License And Collaboration Agreements [Line Items]
Option period				5 years
Option ending period				2022-09
Non refundable and non creditable cash payments				$ 35,000,000
Payment for option exercise		15,000,000
Range of royalties receivable on net sales	high single-digits to mid-teens
Royalties payable description	Royalties will be payable by product and country commencing on the first commercial sale and ending upon the later of: (a) 10 years; and (b) expiration of the last-to-expire valid claim of our patents covering the manufacture, use or sale.
Total collaboration and license revenues	$ 5,000,000	7,000,000	7,000,000
Taiho Pharmaceutical Co., Ltd | Taiho Agreement | Maximum
License And Collaboration Agreements [Line Items]
Payment for option exercise				15,000,000
Additional clinical and regulatory milestone payments receivable				130,000,000
Contingent milestone payments receivable				145,000,000
Taiho Pharmaceutical Co., Ltd | Taiho Agreement | Minimum
License And Collaboration Agreements [Line Items]
Payment for option exercise				3,000,000
WuXi Biologics License Agreement | Research and Development | anti-PD-1
License And Collaboration Agreements [Line Items]
Sub-license fees incurred			10,000,000
Milestone expense		10,000,000	5,000,000
WuXi Biologics License Agreement | Research and Development | anti-CD39
License And Collaboration Agreements [Line Items]
Milestone payments	2,000,000
WuXi Biologics License Agreement | Maximum | anti-PD-1
License And Collaboration Agreements [Line Items]
Clinical, regulatory and commercialization milestone payments				$ 375,000,000
WuXi Biologics License Agreement | Maximum | anti-CD39
License And Collaboration Agreements [Line Items]
Additional clinical, regulatory and commercialization milestone payments	15,000,000
Abmuno License Agreement
License And Collaboration Agreements [Line Items]
Additional clinical, regulatory and commercialization milestone payments	88,000,000
Abmuno License Agreement | Research and Development
License And Collaboration Agreements [Line Items]
Milestone expense	$ 5,000,000	$ 5,000,000	$ 3,000,000