Long-Term Debt and Bank Facility Borrowings - Company's Debt (Detail) - USD ($) $ in Thousands		Mar. 31, 2024	Sep. 30, 2023
Debt Instrument [Line Items]
Long-term debt, carrying Amount		$ 164,928	$ 148,067
Current maturities of long-term debt, carrying Amount		45,739	20,740
Long-term debt	[1]	119,189	127,327
Long-term debt, fair value	[2]	165,489	148,740
Current maturities of long-term debt, fair value	[2]	45,739	20,740
Long-term portion of debt, fair value	[1],[2]	119,750	128,000
Revolving Credit Facility
Debt Instrument [Line Items]
Credit facility borrowings, carrying Amount		29,239	240
Credit facility borrowings, fair value	[2]	29,239	240
Term Loan
Debt Instrument [Line Items]
Long-term debt, carrying Amount	[1]	135,689	147,827
Long-term debt, fair value	[1],[2]	$ 136,250	$ 148,500

[1] Carrying amounts are net of unamortized debt issuance costs of $0.6 million as of March 31, 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.