Fair Value of Company's Contingent Consideration, Investment in Debt Security and Foreign Currency Forward Contracts by Valuation Hierarchy (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Sep. 30, 2020
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Contingent consideration liabilities	$ (5,210)	$ (10,962)
Fair Value, Measurements, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total assets	9,496
Contingent consideration liabilities	(5,210)
Total liabilities	(5,210)
Contingent consideration		(10,962)
Fair Value, Measurements, Recurring | Significant Other Observable (Level 2)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total assets	9,496
Fair Value, Measurements, Recurring | Significant Unobservable (Level 3)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Contingent consideration liabilities	(5,210)
Total liabilities	(5,210)
Contingent consideration		$ (10,962)
Corporate bonds | Fair Value, Measurements, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total assets	9,496
Corporate bonds | Fair Value, Measurements, Recurring | Significant Other Observable (Level 2)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total assets	$ 9,496