Net Loss Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Net loss per share
Net loss	$ (10,193)	$ (2,992)	$ (22,130)	$ (6,376)
Weighted average common shares outstanding, basic and diluted	18,075,010	14,931,931	18,062,803	14,927,558
Net loss per share attributable to common stockholders	$ (0.56)	$ (0.20)	$ (1.23)	$ (0.43)
Potentially dilutive securities
Potentially dilutive securities			2,238,576	2,279,458
Stock options to purchase common stock
Potentially dilutive securities
Potentially dilutive securities			2,190,866	2,231,748
Warrants
Potentially dilutive securities
Potentially dilutive securities			47,710	47,710