Net Loss Per Share - Computation of Basic and Diluted Net Loss Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Earnings Per Share [Abstract]
Net loss	$ (5,684)	$ (3,645)	$ (10,373)	$ (7,028)
Weighted-average common shares outstanding:
Basic and Diluted	22,828,612	22,608,324	22,818,601	19,150,412
Net loss per share, Basic and Diluted	$ (0.25)	$ (0.16)	$ (0.45)	$ (0.37)