Formation and Business of the Company	12 Months Ended
Dec. 31, 2017
Accounting Policies [Abstract]
Formation and Business of the Company	1. Formation and Business of the Company Versartis, Inc. (the “Company”) was incorporated on December 10, 2008 in the State of Delaware. The Company is an endocrine-focused biopharmaceutical company initially developing long-acting recombinant human growth hormone for the treatment of growth hormone deficiency. The Company’s headquarters and operations are in Menlo Park, California. Since incorporation, the Company has been primarily performing research and development activities, including clinical trials, filing patent applications, obtaining regulatory approvals, hiring personnel, and raising capital to support and expand these activities. In September 2017, the Company announced that the VELOCITY Phase 3 clinical trial of somavaratan in pediatric growth hormone deficiency (GHD) failed to meet its primary endpoint of non-inferiority. All ongoing clinical trials of somavaratan have concluded as of December 31, 2017. Analysis of the trial results continues in order to assess the viability of further development of somavaratan. Initial and Secondary Public Offerings In March 2014, the Company completed its initial public offering of shares of its common stock, or IPO, pursuant to which the Company issued 6,900,000 shares of common stock, which includes shares issued pursuant to the underwriters’ exercise of their over-allotment option, and received net proceeds of approximately $132.1 million, after underwriting discounts, commissions and offering expenses. In addition, in connection with the completion of the Company’s IPO, all convertible preferred stock converted into common stock. Effective with the closing of the IPO, the Company’s Amended and Restated Certificate of Incorporation authorizes the Company to issue 50.0 million shares of common stock and 5.0 million shares of preferred stock. In January 2015, the Company completed a secondary public offering of common stock, pursuant to which the Company issued 4,999,999 shares of common stock, which includes shares issued pursuant to the underwriters’ exercise of their over-allotment option, and received net proceeds of approximately $80.2 million, after underwriting discounts, commissions and estimated offering expenses. In October and November 2016, the Company completed a follow-on offering of common stock, pursuant to which the Company issued 5,176,545 shares of common stock, which includes shares issued pursuant to the underwriters’ partial exercise of their over-allotment option, and received net proceeds of approximately $59.1 million, after underwriting discounts, commissions and offering expenses.

1. Formation and Business of the Company

Versartis, Inc. (the “Company”) was incorporated on December 10, 2008 in the State of Delaware. The Company is an endocrine-focused biopharmaceutical company initially developing long-acting recombinant human growth hormone for the treatment of growth hormone deficiency.

The Company’s headquarters and operations are in Menlo Park, California. Since incorporation, the Company has been primarily performing research and development activities, including clinical trials, filing patent applications, obtaining regulatory approvals, hiring personnel, and raising capital to support and expand these activities.

In September 2017, the Company announced that the VELOCITY Phase 3 clinical trial of somavaratan in pediatric growth hormone deficiency (GHD) failed to meet its primary endpoint of non-inferiority. All ongoing clinical trials of somavaratan have concluded as of December 31, 2017. Analysis of the trial results continues in order to assess the viability of further development of somavaratan.

Initial and Secondary Public Offerings

In March 2014, the Company completed its initial public offering of shares of its common stock, or IPO, pursuant to which the Company issued 6,900,000 shares of common stock, which includes shares issued pursuant to the underwriters’ exercise of their over-allotment option, and received net proceeds of approximately $132.1 million, after underwriting discounts, commissions and offering expenses. In addition, in connection with the completion of the Company’s IPO, all convertible preferred stock converted into common stock. Effective with the closing of the IPO, the Company’s Amended and Restated Certificate of Incorporation authorizes the Company to issue 50.0 million shares of common stock and 5.0 million shares of preferred stock.

In January 2015, the Company completed a secondary public offering of common stock, pursuant to which the Company issued 4,999,999 shares of common stock, which includes shares issued pursuant to the underwriters’ exercise of their over-allotment option, and received net proceeds of approximately $80.2 million, after underwriting discounts, commissions and estimated offering expenses.

In October and November 2016, the Company completed a follow-on offering of common stock, pursuant to which the Company issued 5,176,545 shares of common stock, which includes shares issued pursuant to the underwriters’ partial exercise of their over-allotment option, and received net proceeds of approximately $59.1 million, after underwriting discounts, commissions and offering expenses.