Property and Equipment, Net - Property and Equipment (Details) - USD ($) $ in Thousands	Jan. 31, 2017	Jan. 31, 2016
Property Plant And Equipment [Line Items]
Total property and equipment, gross	$ 14,249	$ 9,599
Less: accumulated depreciation and amortization	(9,607)	(5,824)
Property and equipment, net	4,642	3,775
Furniture and equipment
Property Plant And Equipment [Line Items]
Total property and equipment, gross	1,415	870
Software development costs
Property Plant And Equipment [Line Items]
Total property and equipment, gross	12,376	8,077
Leasehold improvements
Property Plant And Equipment [Line Items]
Total property and equipment, gross	$ 458	414
Construction in progress
Property Plant And Equipment [Line Items]
Total property and equipment, gross		$ 238