Property and Equipment, Net - Schedule of Property and Equipment (Detail) - USD ($) $ in Thousands	Oct. 31, 2016	Jan. 31, 2016
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 12,966	$ 11,301
Less: accumulated depreciation and amortization	(8,675)	(7,853)
Total property and equipment, net	4,291	3,448
Computer equipment and software [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	6,585	6,421
Machinery and equipment [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	3,427	2,706
Furniture and fixtures [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	789	492
Leasehold improvements [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	1,571	1,429
Construction in progress [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 594	$ 253