Organization	9 Months Ended
Sep. 30, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Organization	Note 1. Organization Description of Business Arcus Biosciences, Inc. (Company or the Company) is a clinical-stage biopharmaceutical company focused on creating innovative cancer immunotherapies by leveraging underexploited biological opportunities. Specifically, the Company targets well-characterized biological pathways with significant scientific data supporting their importance in regulating the immune response against cancer and for which either there are no molecules in development or those that exist have suboptimal profiles. To exploit these pathways, the Company has built a robust and highly efficient discovery and clinical development capability to create and optimize highly differentiated small-molecule immuno-oncology product candidates. Since its inception in 2015, the Company has built a broad portfolio of small molecule and antibody product candidates that it plans to develop together as intra-portfolio combinations. Liquidity and Capital Resources As of September 30, 2019, the Company had cash and investments of $197.0 million, which are cash, cash equivalents, and investments in marketable securities that the Company believes will be sufficient to fund its planned operations for a period of at least twelve months following the filing date of this report.

Organization

9 Months Ended

Sep. 30, 2019

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Note 1. Organization

Description of Business

Arcus Biosciences, Inc. (Company or the Company) is a clinical-stage biopharmaceutical company focused on creating innovative cancer immunotherapies by leveraging underexploited biological opportunities. Specifically, the Company targets well-characterized biological pathways with significant scientific data supporting their importance in regulating the immune response against cancer and for which either there are no molecules in development or those that exist have suboptimal profiles. To exploit these pathways, the Company has built a robust and highly efficient discovery and clinical development capability to create and optimize highly differentiated small-molecule immuno-oncology product candidates. Since its inception in 2015, the Company has built a broad portfolio of small molecule and antibody product candidates that it plans to develop together as intra-portfolio combinations.

Liquidity and Capital Resources

As of September 30, 2019, the Company had cash and investments of $197.0 million, which are cash, cash equivalents, and investments in marketable securities that the Company believes will be sufficient to fund its planned operations for a period of at least twelve months following the filing date of this report.