Long-Term Debt and Bank Facility Borrowings - Company's Debt (Parenthetical) (Detail) - USD ($) $ in Millions	Mar. 31, 2022	Sep. 30, 2021
Term Loan
Debt Instrument [Line Items]
Unamortized debt issuance costs	$ 0.4	$ 0.5

Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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