Fair Value of Financial Instruments - Fair Value of Company's Short-Term Investment and Contingent Consideration by Valuation Hierarchy (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Sep. 30, 2021
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Current portion contingent consideration liabilities	$ 167	$ 807
Non-current portion contingent consideration liabilities	385	5,210
Fair Value, Measurements, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total assets	3,660	9,496
Current portion contingent consideration liabilities	167
Non-current portion contingent consideration liabilities	385	6,017
Total liabilities	552	6,017
Fair Value, Measurements, Recurring | Significant Other Observable (Level 2)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total assets	3,660	9,496
Fair Value, Measurements, Recurring | Significant Unobservable (Level 3)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Current portion contingent consideration liabilities	167
Non-current portion contingent consideration liabilities	385	6,017
Total liabilities	552	6,017
Fair Value, Measurements, Recurring | Corporate bonds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total assets	3,660	9,496
Fair Value, Measurements, Recurring | Corporate bonds | Significant Other Observable (Level 2)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Total assets	$ 3,660	$ 9,496