Long-Term Debt and Bank Facility Borrowings - Company's Debt (Detail) - USD ($) $ in Thousands		Jun. 30, 2024	Sep. 30, 2023
Debt Instrument [Line Items]
Long-term debt, carrying Amount		$ 136,013	$ 148,067
Current maturities of long-term debt, carrying Amount		20,896	20,740
Long-term debt	[1]	115,117	127,327
Long-term debt, fair value	[2]	136,521	148,740
Current maturities of long-term debt, fair value	[2]	20,896	20,740
Long-term portion of debt, fair value	[1],[2]	115,625	128,000
Revolving Credit Facility
Debt Instrument [Line Items]
Credit facility borrowings, carrying Amount		4,396	240
Credit facility borrowings, fair value	[2]	4,396	240
Term Loan
Debt Instrument [Line Items]
Long-term debt, carrying Amount	[1]	131,617	147,827
Long-term debt, fair value	[1],[2]	$ 132,125	$ 148,500

[1] Carrying amounts are net of unamortized debt issuance costs of $0.5 million as of June 30, 2024 and $0.7 million as of September 30, 2023

[2] The face amount of the Company’s variable rate long-term debt approximates fair value.