Long-Term Debt and Bank Facility Borrowings - Company's Debt (Parenthetical) (Detail) - USD ($) $ in Thousands		9 Months Ended
		Jun. 30, 2022	Jun. 30, 2021	Sep. 30, 2021
Debt Instrument [Line Items]
Long term debt		$ 225,024		$ 118,624
Loan repayment		14,615	$ 9,750
Term Loan
Debt Instrument [Line Items]
Unamortized debt issuance costs		400		500
Long term debt	[1]	95,514		$ 110,006
Loan repayment		95,900
Revolving Credit Facility
Debt Instrument [Line Items]
Long term debt		69,100
Loan repayment		$ 69,100

[1] Carrying amounts are net of unamortized debt issuance costs of $0.4 million as of June 30, 2022 and $0.5 million as of September 30, 2021