Property and Equipment, Net - Schedule of Property and Equipment (Detail) - USD ($) $ in Thousands	Jul. 31, 2018	Jan. 31, 2018
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 18,176	$ 16,381
Less: accumulated depreciation and amortization	(11,166)	(9,932)
Total property and equipment, net	7,010	6,449
Computer equipment and software [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	9,175	8,611
Machinery and equipment [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	5,398	4,761
Furniture and fixtures [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	938	917
Leasehold improvements [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	2,239	2,092
Construction in progress [Member]
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 426	$ 0

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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