Shareholders' Equity

12 Months Ended

Dec. 31, 2018

Stockholders' Equity Note [Abstract]

Shareholders' Equity

Shareholders’ Equity

At-the-Market Sales Agreement

On October 10, 2016, the Company entered into an at-the-market sales agreement with Cowen (ATM Agreement), pursuant to which the Company sold shares of its common stock through Cowen, as sales agent, in registered transactions from the Company's shelf registration statement filed in June 2015.  Shares of common stock were sold under the ATM at market prices.  The Company paid 3% of the gross proceeds to Cowen as a commission. A total of 2,340,879 shares of common stock were sold under the ATM Agreement for proceeds of $8.0 million (net of $0.3 million in commission and issuance costs). There were no shares sold under the ATM Agreement during 2018. Effective May 29, 2018, the Company terminated the ATM Agreement and no further sales pursuant to the ATM Agreement will be made following such date of termination

Public Equity Offering

In June 2018, the Company sold 5,750,000 shares of its common stock in an underwritten public offering at a price of $13.00 per share.  The Company received proceeds of $70.1 million, net of $4.7 million of underwriters’ discount and issuance costs consisting primarily of legal and accounting fees. The Company recorded these proceeds as a common stock issuance.

Dividends

 No cash dividends have been declared or paid by the Company since its inception.