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		9 Months Ended
	Oct. 31, 2016	Oct. 31, 2015	Oct. 31, 2016	Oct. 31, 2015
Numerator
Net loss	$ (2,821)	$ (3,531)	$ (10,117)	$ (10,869)
Denominator
Weighted-average common shares for basic and diluted net loss per share	17,648,251	16,703,852	17,337,682	7,875,761
Basic and diluted net loss per share	$ (0.16)	$ (0.21)	$ (0.58)	$ (1.38)