Property and Equipment, Net - Additional Information (Details) - USD ($)	12 Months Ended
	Jan. 31, 2017	Jan. 31, 2016	Jan. 31, 2015
Property Plant And Equipment [Abstract]
Depreciation and amortization expense excluding software development costs	$ 432,000	$ 256,000	$ 105,000
Amortization expense related to software development costs	$ 3,300,000	$ 2,200,000	$ 1,200,000