Organization and Description of Business and Significant Accounting Policies - Schedule of Non-Vested Restricted Stock Units Compensation (Detail) - USD ($) $ in Thousands |
12 Months Ended | |
|---|---|---|
Sep. 30, 2022 |
Sep. 30, 2021 |
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||
| Total expected compensation expense related to RSUs | $ 1,252 | $ 1,438 |
| Restricted Stock Units (RSUs) [Member] | ||
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ||
| Total expected compensation expense related to RSUs | 18,143 | |
| Recognized compensation expense related to RSUs | (15,570) | |
| Unrecognized compensation expense related to RSUS | $ 2,573 | |
| Weighted average remaining period to expense for RSUs | 3 years | |