Organization and Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands |
Apr. 30, 2019 |
Feb. 01, 2019 |
Jan. 31, 2019 |
|---|---|---|---|
| Summary Of Significant Accounting Policies [Line Items] | |||
| Right-of-use assets | $ 7,911 | $ 0 | |
| Lease liabilities | $ 8,025 | ||
| ASU 2016-02 [Member] | |||
| Summary Of Significant Accounting Policies [Line Items] | |||
| Right-of-use assets | $ 8,581 | ||
| Lease liabilities | $ 8,700 |