Formation and Business of the Company	6 Months Ended
Jun. 30, 2018
Accounting Policies [Abstract]
Formation and Business of the Company	1. Formation and Business of the Company Versartis, Inc., or the Company, was incorporated on December 10, 2008 in the State of Delaware. The Company has been an endocrine-focused biopharmaceutical company that was developing a 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, or GHD, failed to meet its primary endpoint of non-inferiority. All ongoing clinical trials of somavaratan have concluded and currently the Company does not intend to further develop somavaratan. In June 2018, the Company entered into a merger agreement with Aravive Biologics, Inc. to form a clinical stage, Nasdaq-listed company, based in Houston, Texas, focused on the development of innovative oncology therapeutics. Aravive Biologics is a privately held clinical stage biopharmaceutical company developing novel, highly selective therapies designed to treat serious cancers and certain fibrotic diseases. Under this merger agreement, Aravive will merge with a wholly owned subsidiary of Versartis in an all-stock transaction. Following the proposed merger, Versartis and Aravive equity holders are each expected to own approximately 50 percent of the combined company. This transaction is expected to close during the second half of 2018, subject to approval by the stockholders of both companies and the satisfaction or waiver of other customary closing conditions. Unaudited Interim Financial Information In the opinion of the Company, the accompanying unaudited condensed consolidated financial statements contain all adjustments, consisting of only normal recurring adjustments, necessary for a fair statement of its financial position as of June 30, 2018, its results of operations three- and six- month periods ended June 30, 2018, and 2017, cash flows three- and six- months ended June 30, 2018, and 2017. The December 31, 2017 condensed consolidated balance sheet was derived from audited financial statements, but does not include all disclosures required by generally accepted accounting principles in the United States of America, or GAAP. The results for interim periods are not necessarily indicative of the results for the entire year or any other interim period. The accompanying condensed consolidated financial statements and related financial information should be read in conjunction with the audited financial statements and the related notes thereto for the year ended December 31, 2017 included in the Company’s annual report on Form 10-K filed on March 6, 2018 with the U.S. Securities and Exchange Commission, or the SEC.

1. Formation and Business of the Company

Versartis, Inc., or the Company, was incorporated on December 10, 2008 in the State of Delaware. The Company has been an endocrine-focused biopharmaceutical company that was developing a 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, or GHD, failed to meet its primary endpoint of non-inferiority. All ongoing clinical trials of somavaratan have concluded and currently the Company does not intend to further develop somavaratan.

In June 2018, the Company entered into a merger agreement with Aravive Biologics, Inc. to form a clinical stage, Nasdaq-listed company, based in Houston, Texas, focused on the development of innovative oncology therapeutics. Aravive Biologics is a privately held clinical stage biopharmaceutical company developing novel, highly selective therapies designed to treat serious cancers and certain fibrotic diseases. Under this merger agreement, Aravive will merge with a wholly owned subsidiary of Versartis in an all-stock transaction. Following the proposed merger, Versartis and Aravive equity holders are each expected to own approximately 50 percent of the combined company. This transaction is expected to close during the second half of 2018, subject to approval by the stockholders of both companies and the satisfaction or waiver of other customary closing conditions.

Unaudited Interim Financial Information

In the opinion of the Company, the accompanying unaudited condensed consolidated financial statements contain all adjustments, consisting of only normal recurring adjustments, necessary for a fair statement of its financial position as of June 30, 2018, its results of operations three- and six- month periods ended June 30, 2018, and 2017, cash flows three- and six- months ended June 30, 2018, and 2017. The December 31, 2017 condensed consolidated balance sheet was derived from audited financial statements, but does not include all disclosures required by generally accepted accounting principles in the United States of America, or GAAP. The results for interim periods are not necessarily indicative of the results for the entire year or any other interim period. The accompanying condensed consolidated financial statements and related financial information should be read in conjunction with the audited financial statements and the related notes thereto for the year ended December 31, 2017 included in the Company’s annual report on Form 10-K filed on March 6, 2018 with the U.S. Securities and Exchange Commission, or the SEC.