Stockholders’ Equity	12 Months Ended
Dec. 31, 2018
Equity [Abstract]
Stockholders’ Equity	10. Stockholders’ Equity On May 11, 2016, the Company completed an initial public offering (“IPO”) of its common stock, which resulted in the sale of 6,900,000 shares, including all additional shares available to cover over-allotments, at a price of $18.00 per share. The Company received net proceeds before expenses from the IPO of $115.5 million after deducting underwriting discounts and commissions paid by the Company. In preparation for the IPO, the Company’s board of directors and stockholders approved a one-for-1.7 reverse stock split of the Company’s common stock effective April 25, 2016. All share and per share amounts in the consolidated financial statements and notes thereto have been retroactively adjusted, where necessary, to give effect to this reverse stock split. In connection with the closing of the IPO, all of the Company’s outstanding convertible preferred stock automatically converted to common stock at a one-for-0.6465903 ratio as of May 11, 2016, resulting in an additional 23,481,956 shares of common stock of the Company becoming outstanding. In addition, the Company issued a total of 3,055,554 shares of common stock for $55.0 million in two separate, concurrent private placements upon the closing of the IPO. On November 1, 2017, the Company entered into an underwriting agreement related to a public offering of 6,250,000 shares of the Company’s common stock, par value $0.0001 per share. The offering closed on November 6th and the Company received net proceeds of $141.0 million, after deducting underwriting discounts. On October 12, 2018, the Company filed a Registration Statement on Form S-3 (the “Shelf”) with the SEC in relation to the registration of common stock, preferred stock, warrants and/or units of any combination thereof (collectively, the “Securities”). The Company also simultaneously entered into an Open Market Sale Agreement (the “Sales Agreement”) with Jefferies LLC, (the “Sales Agent”), to provide for the offering, issuance and sale by the Company of up to an aggregate amount of $100.0 million of its common stock from time to time in “at-the-market” offerings under the Shelf and subject to the limitations thereof. On November 15, 2018, the Company issued 1,659,300 shares of its common stock in accordance with the Sales Agreement for net proceeds of $29.0 million, after payment of cash commissions of 3.0 percent of the gross proceeds to the Sales Agent. Additionally, the Company incurred approximately $0.4 million related to legal, accounting and other fees in connection with the Sales Agreement and subsequent sale. The Company classifies stock that is redeemable in circumstances outside of the Company’s control outside of permanent equity. The Company recorded convertible preferred stock at fair value upon issuance, net of any issuance costs or discounts. No accretion was recognized as the contingent events that could give rise to redemption were not deemed probable. The preferred stock outstanding at December 31, 2015 was automatically converted to common stock in connection with the closing of the IPO.

Stockholders’ Equity

12 Months Ended

Dec. 31, 2018

10. Stockholders’ Equity

On May 11, 2016, the Company completed an initial public offering (“IPO”) of its common stock, which resulted in the sale of 6,900,000 shares, including all additional shares available to cover over-allotments, at a price of $18.00 per share. The Company received net proceeds before expenses from the IPO of $115.5 million after deducting underwriting discounts and commissions paid by the Company. In preparation for the IPO, the Company’s board of directors and stockholders approved a one-for-1.7 reverse stock split of the Company’s common stock effective April 25, 2016. All share and per share amounts in the consolidated financial statements and notes thereto have been retroactively adjusted, where necessary, to give effect to this reverse stock split. In connection with the closing of the IPO, all of the Company’s outstanding convertible preferred stock automatically converted to common stock at a one-for-0.6465903 ratio as of May 11, 2016, resulting in an additional 23,481,956 shares of common stock of the Company becoming outstanding. In addition, the Company issued a total of 3,055,554 shares of common stock for $55.0 million in two separate, concurrent private placements upon the closing of the IPO.

On November 1, 2017, the Company entered into an underwriting agreement related to a public offering of 6,250,000 shares of the Company’s common stock, par value $0.0001 per share. The offering closed on November 6th and the Company received net proceeds of $141.0 million, after deducting underwriting discounts.

On October 12, 2018, the Company filed a Registration Statement on Form S-3 (the “Shelf”) with the SEC in relation to the registration of common stock, preferred stock, warrants and/or units of any combination thereof (collectively, the “Securities”). The Company also simultaneously entered into an Open Market Sale Agreement (the “Sales Agreement”) with Jefferies LLC, (the “Sales Agent”), to provide for the offering, issuance and sale by the Company of up to an aggregate amount of $100.0 million of its common stock from time to time in “at-the-market” offerings under the Shelf and subject to the limitations thereof. On November 15, 2018, the Company issued 1,659,300 shares of its common stock in accordance with the Sales Agreement for net proceeds of $29.0 million, after payment of cash commissions of 3.0 percent of the gross proceeds to the Sales Agent. Additionally, the Company incurred approximately $0.4 million related to legal, accounting and other fees in connection with the Sales Agreement and subsequent sale.

The Company classifies stock that is redeemable in circumstances outside of the Company’s control outside of permanent equity. The Company recorded convertible preferred stock at fair value upon issuance, net of any issuance costs or discounts. No accretion was recognized as the contingent events that could give rise to redemption were not deemed probable. The preferred stock outstanding at December 31, 2015 was automatically converted to common stock in connection with the closing of the IPO.