Revenues - Additional Information (Details) - USD ($) $ in Millions		1 Months Ended	3 Months Ended		6 Months Ended
	Jul. 13, 2020	May 31, 2023	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
License And Collaboration Agreements [Line Items]
Allocated transaction price					$ 35
Total collaboration and license revenues			$ 29	$ 27	54	$ 45
Deferred revenue recognized			28	$ 27	53	$ 45
Gilead
License And Collaboration Agreements [Line Items]
Cost sharing receivable			4		4
Gilead | Prepaid Expenses and Other Current Assets
License And Collaboration Agreements [Line Items]
Capitalized Contract Cost, Net, Current			1		1
Gilead | Other Noncurrent Assets
License And Collaboration Agreements [Line Items]
Capitalized Contract Cost, Net, Noncurrent			$ 3		$ 3
Customer Concentration Risk | Gilead | Revenue Benchmark
License And Collaboration Agreements [Line Items]
Percentage of revenues			100.00%	96.00%	100.00%	93.00%
Gilead Collaboration Agreement
License And Collaboration Agreements [Line Items]
Deferred revenue			$ 433		$ 433		$ 452
Gilead Collaboration Agreement | Gilead
License And Collaboration Agreements [Line Items]
Deferred revenue			167		167
Upfront cash payment			35
Allocated transaction price		$ 35
Total collaboration and license revenues			10	$ 13	18	$ 18
Deferred revenue recognized	$ 121				219
Current and future programs exclusive access period	10 years
Contingent milestone payments receivable	$ 300
Option continuation payment receivable upon sixth anniversary of agreement	$ 100
Performance obligation period	4 years
R&D Activities for Inflammation Programs | Gilead
License And Collaboration Agreements [Line Items]
Deferred revenue			34		34
Total collaboration and license revenues			1		1
R&D activities for Domvanalimab
License And Collaboration Agreements [Line Items]
Deferred revenue			28		28
Total collaboration and license revenues			1	1	2	2
Deferred revenue recognized					34
Quemliclustat, License and R&D services | Gilead
License And Collaboration Agreements [Line Items]
Deferred revenue			134		134
Total collaboration and license revenues			7	2	15	4
Deferred revenue recognized					176
R&D and Commercialization Activities for Zimberelimab
License And Collaboration Agreements [Line Items]
Total collaboration and license revenues			1	1	1	1
Deferred revenue recognized					11
Access rights and option continuation periods
License And Collaboration Agreements [Line Items]
Deferred revenue			70		70
Total collaboration and license revenues			$ 9	$ 9	$ 17	$ 17