Basic and Diluted Net Loss Per Share - Computation of Basic and Diluted Net Loss Per Share of Common Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2017	Jul. 31, 2016
Numerator
Net loss	$ (3,623)	$ (3,340)	$ (7,015)	$ (7,296)
Denominator
Weighted-average common shares for basic and diluted net loss per share	18,360,560	17,280,985	18,246,457	17,180,671
Basic and diluted net loss per share	$ (0.20)	$ (0.19)	$ (0.38)	$ (0.42)