Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Assets and Liabilities Measured at Fair Value on a Recurring Basis [Member] - USD ($) $ in Thousands	Sep. 30, 2022	Sep. 30, 2021
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets measured at fair value	$ 2,035	$ 15,027
Liabilities measured at fair value	829	817
Available-for-sale investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets measured at fair value		9,719
Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets measured at fair value	2,035	15,027
Significant Other Observable Inputs (Level 2) [Member] | Available-for-sale investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets measured at fair value		9,719
Level 3 Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Liabilities measured at fair value	829	817
Cash equivalents [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets measured at fair value	2,035	5,308
Cash equivalents [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets measured at fair value	2,035	5,308
Contingent consideration [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Liabilities measured at fair value	829	817
Contingent consideration [Member] | Level 3 Liabilities [Member]
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Liabilities measured at fair value	$ 829	$ 817