Stockholders' Equity	3 Months Ended
Mar. 31, 2020
Equity [Abstract]
Stockholders' Equity	Note 7. Stockholders’ Equity Public Offering of Common Stock In January 2020, the Company issued and sold 16,866,667 shares of common stock, par value $0.001 per share, at $3.75 per share in an underwritten public offering. The total proceeds from this offering were approximately $62.7 million, net of the underwriting discount and other issuance costs. Sales Agreement On August 4, 2017, the Company entered into Amendment No. 3 to the Controlled Equity Offering ^SM Sales Agreement with Cantor Fitzgerald & Co. (as amended on August 4, 2017, the “Amended Cantor Agreement”). The Amended Cantor Agreement became effective on January 8, 2018, and provided for the issuance and sale of shares of the Company’s common stock having an aggregate offering price of up to $70.0 million through Cantor Fitzgerald & Co. (“Cantor”), which amount included the $31.4 million of unsold shares of common stock available for sale immediately prior to the effectiveness of the Amended Cantor Agreement. Under the Amended Cantor Agreement, Cantor also acts as the Company’s sales agent and receives compensation based on an aggregate of 2% of the gross proceeds on the sale price per share of its common stock. The issuance and sale of these shares by the Company pursuant to the Amended Cantor Agreement are deemed an “at-the-market” offering and are registered under the Securities Act of 1933, as amended. During the three months ended March 31, 2020, 1.0 million shares of the Company’s common stock were sold under the Amended Cantor Agreement for net proceeds of $4.4 million. At March 31, 2020, the Company had approximately $9.6 million of common stock available to be sold under the Amended Cantor Agreement.

Stockholders' Equity

3 Months Ended

Mar. 31, 2020

Note 7. Stockholders’ Equity

Public Offering of Common Stock

In January 2020, the Company issued and sold 16,866,667 shares of common stock, par value $0.001 per share, at $3.75 per share in an underwritten public offering. The total proceeds from this offering were approximately $62.7 million, net of the underwriting discount and other issuance costs.

Sales Agreement

On August 4, 2017, the Company entered into Amendment No. 3 to the Controlled Equity Offering ^SM Sales Agreement with Cantor Fitzgerald & Co. (as amended on August 4, 2017, the “Amended Cantor Agreement”). The Amended Cantor Agreement became effective on January 8, 2018, and provided for the issuance and sale of shares of the Company’s common stock having an aggregate offering price of up to $70.0 million through Cantor Fitzgerald & Co. (“Cantor”), which amount included the $31.4 million of unsold shares of common stock available for sale immediately prior to the effectiveness of the Amended Cantor Agreement. Under the Amended Cantor Agreement, Cantor also acts as the Company’s sales agent and receives compensation based on an aggregate of 2% of the gross proceeds on the sale price per share of its common stock. The issuance and sale of these shares by the Company pursuant to the Amended Cantor Agreement are deemed an “at-the-market” offering and are registered under the Securities Act of 1933, as amended. During the three months ended March 31, 2020, 1.0 million shares of the Company’s common stock were sold under the Amended Cantor Agreement for net proceeds of $4.4 million. At March 31, 2020, the Company had approximately $9.6 million of common stock available to be sold under the Amended Cantor Agreement.