Stockholders' Equity	9 Months Ended
Sep. 30, 2020
Stockholders Equity Note [Abstract]
Stockholders' Equity	Note 7. Stockholders’ Equity In June 2020, pursuant to a shelf registration statement on Form S-3 that was filed in May 2020, the Company issued 12,650,000 shares of its common stock at $27.50 per share in an underwritten public offering (the May 2020 Public Offering). The total number of shares sold consisted of 11,000,000 base shares and an additional 1,650,000 shares sold pursuant to the underwriters’ option exercise. Net proceeds from the May 2020 Public Offering were approximately $326.2 million after deducting underwriting discounts, commissions and other offering expenses. In July 2020, the Company closed the Gilead Collaboration Agreement, Common Stock Purchase Agreement, and the Investor Rights Agreement, each signed with Gilead in May 2020. The transaction closed on July 13, 2020 following expiration of the antitrust waiting period. Upon closing, Gilead made an equity investment of approximately $200 million in the Company by purchasing 5,963,029 shares of Arcus common stock at a per share price of $33.54 pursuant to the Stock Purchase Agreement. Of the $200 million equity investment, approximately $90.6 million was determined to be a premium on the purchase of common stock and allocated to the performance obligations created by the Gilead Collaboration Agreement. See Note 6 in this Form 10-Q for further discussion of the agreements with Gilead. Net proceeds from Gilead’s equity investment were approximately $107.5 million after allocating the premium and deducting direct offering expenses of $1.9 million.

Stockholders' Equity

9 Months Ended

Sep. 30, 2020

Note 7. Stockholders’ Equity

In June 2020, pursuant to a shelf registration statement on Form S-3 that was filed in May 2020, the Company issued 12,650,000 shares of its common stock at $27.50 per share in an underwritten public offering (the May 2020 Public Offering). The total number of shares sold consisted of 11,000,000 base shares and an additional 1,650,000 shares sold pursuant to the underwriters’ option exercise. Net proceeds from the May 2020 Public Offering were approximately $326.2 million after deducting underwriting discounts, commissions and other offering expenses.

In July 2020, the Company closed the Gilead Collaboration Agreement, Common Stock Purchase Agreement, and the Investor Rights Agreement, each signed with Gilead in May 2020. The transaction closed on July 13, 2020 following expiration of the antitrust waiting period. Upon closing, Gilead made an equity investment of approximately $200 million in the Company by purchasing 5,963,029 shares of Arcus common stock at a per share price of $33.54 pursuant to the Stock Purchase Agreement. Of the $200 million equity investment, approximately $90.6 million was determined to be a premium on the purchase of common stock and allocated to the performance obligations created by the Gilead Collaboration Agreement. See Note 6 in this Form 10-Q for further discussion of the agreements with Gilead. Net proceeds from Gilead’s equity investment were approximately $107.5 million after allocating the premium and deducting direct offering expenses of $1.9 million.