Property and Equipment, Net - Schedule of Property and Equipment (Detail) - USD ($) $ in Thousands	Jul. 31, 2016	Jan. 31, 2016
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 12,243	$ 11,301
Less: accumulated depreciation and amortization	(8,601)	(7,853)
Total property and equipment, net	3,642	3,448
Computer equipment and software [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	6,700	6,421
Machinery and equipment [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	3,004	2,706
Furniture and fixtures [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	794	492
Leasehold improvements [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	1,550	1,429
Construction in progress [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 195	$ 253