Fair Value Measurements - Assets Categorized on Basis of Various Levels (Detail) - USD ($) $ in Thousands |
Sep. 30, 2022 |
Sep. 30, 2021 |
|---|---|---|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Money market fund deposits | $ 54,225 | $ 11,554 |
| Mutual fund investments | 9 | 10 |
| Cash and cash equivalents | 54,225 | 11,554 |
| Investments in marketable securities | 9 | 10 |
| Total | 54,234 | 11,564 |
| Level 1 [Member] | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Money market fund deposits | 54,225 | 11,554 |
| Mutual fund investments | 9 | 10 |
| Cash and cash equivalents | 54,225 | 11,554 |
| Investments in marketable securities | 9 | 10 |
| Total | $ 54,234 | $ 11,564 |