Long-Term Debt and Bank Facility Borrowings - Company's Debt (Detail) - USD ($) $ in Thousands		Dec. 31, 2022	Sep. 30, 2022
Debt Instrument [Line Items]
Long-term debt, carrying Amount		$ 296,596	$ 184,360
Current maturities of long-term debt, carrying Amount		153,074	32,651
Long-term debt	[1]	143,522	151,709
Long-term debt, fair value	[2]	297,449	185,276
Current maturities of long-term debt, fair value	[2]	153,074	32,651
Long-term portion of debt, fair value	[1],[2]	144,375	152,625
Revolving Credit Facility
Debt Instrument [Line Items]
Credit facility borrowings, carrying Amount		136,574	20,276
Credit facility borrowings, fair value	[2]	136,574	20,276
Term Loan
Debt Instrument [Line Items]
Long-term debt, carrying Amount	[1]	160,022	164,084
Long-term debt, fair value	[1],[2]	$ 160,875	$ 165,000

[1] Carrying amounts are net of unamortized debt issuance costs of $0.9 million as of December 31, 2022 and $0.9 million as of September 30, 2022

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