Property and Equipment, Net - Schedule of Property and Equipment (Detail) - USD ($) $ in Thousands |
Apr. 30, 2019 |
Jan. 31, 2019 |
|---|---|---|
| Property Plant And Equipment [Line Items] | ||
| Property and equipment, gross | $ 18,687 | $ 18,387 |
| Less: accumulated depreciation and amortization | (12,304) | (11,659) |
| Total property and equipment, net | 6,383 | 6,728 |
| Computer equipment and software [Member] | ||
| Property Plant And Equipment [Line Items] | ||
| Property and equipment, gross | 9,379 | 9,098 |
| Machinery and equipment [Member] | ||
| Property Plant And Equipment [Line Items] | ||
| Property and equipment, gross | 5,703 | 5,659 |
| Furniture and fixtures [Member] | ||
| Property Plant And Equipment [Line Items] | ||
| Property and equipment, gross | 969 | 969 |
| Leasehold improvements [Member] | ||
| Property Plant And Equipment [Line Items] | ||
| Property and equipment, gross | 2,318 | 2,331 |
| Construction in progress [Member] | ||
| Property Plant And Equipment [Line Items] | ||
| Property and equipment, gross | $ 318 | $ 330 |