Long-Term Debt and Bank Facility Borrowings - Company's Debt (Detail) - USD ($) $ in Thousands		Dec. 31, 2023	Sep. 30, 2023
Debt Instrument [Line Items]
Long-term debt, carrying Amount		$ 195,760	$ 148,067
Current maturities of long-term debt, carrying Amount		72,502	20,740
Long-term debt	[1]	123,258	127,327
Long-term debt, fair value	[2]	196,377	148,740
Current maturities of long-term debt, fair value	[2]	72,502	20,740
Long-term portion of debt, fair value	[1],[2]	123,875	128,000
Revolving Credit Facility
Debt Instrument [Line Items]
Credit facility borrowings, carrying Amount		51,877	240
Credit facility borrowings, fair value	[2]	51,877	240
Term Loan
Debt Instrument [Line Items]
Long-term debt, carrying Amount	[1]	143,883	147,827
Long-term debt, fair value	[1],[2]	$ 144,500	$ 148,500

[1] Carrying amounts are net of unamortized debt issuance costs of $0.6 million as of December 31, 2023 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.