Goodwill and Other Intangible Assets - Future Estimated Amortization Expense Related to Amortizable Intangible Assets (Detail) - USD ($) $ in Thousands |
Apr. 30, 2018 |
Jan. 31, 2018 |
|---|---|---|
| Goodwill and Intangible Assets Disclosure [Abstract] | ||
| 2019 | $ 1,353 | |
| 2020 | 1,789 | |
| 2021 | 1,638 | |
| 2022 | 1,150 | |
| 2023 | 964 | |
| Thereafter | 4,590 | |
| Net Carrying Amount | $ 11,484 | $ 8,015 |