Property and Equipment, Net - Schedule of Property and Equipment (Detail) (USD $) In Thousands, unless otherwise specified	Apr. 30, 2015	Jan. 31, 2015
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 9,574	$ 9,279
Less: accumulated depreciation and amortization	(6,552)	(6,204)
Total property and equipment, net	3,022	3,075
Computer equipment and software [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	5,455	5,310
Machinery and equipment [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	2,263	2,234
Furniture and fixtures [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	456	456
Leasehold improvements [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	1,228	1,215
Construction in progress [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 172	$ 64