Cover - shares	6 Months Ended
	Jun. 30, 2024	Aug. 01, 2024
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2024
Document Transition Report	false
Entity File Number	001-38419
Entity Registrant Name	Arcus Biosciences, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	47-3898435
Entity Address, Address Line One	3928 Point Eden Way
Entity Address, City or Town	Hayward
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94545
City Area Code	510
Local Phone Number	694-6200
Title of 12(b) Security	Common Stock, Par Value $0.0001 Per Share
Trading Symbol	RCUS
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		91,427,505
Entity Central Index Key	0001724521
Current Fiscal Year End Date	--12-31
Amendment Flag	false
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q2