Stockholders' Equity (Details 2) - USD ($) $ / shares in Units, shares in Millions	1 Months Ended
	Jan. 31, 2015	Jun. 19, 2015
Private Placement
Stockholders' equity
Proceeds from sale of stock, net of commissions and other offering costs	$ 19,300,000
Private Placement | Common stock
Stockholders' equity
Issuance of stock (in shares)	3.4
Share price (in dollars per share)	$ 5.85
2015 Shelf Registration
Stockholders' equity
Aggregate amount of securities issuable		$ 150,000,000