Goodwill and Intangible Assets - Amortization Expense Associated with Intangible Assets (Detail) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Amortization expense of intangible assets	$ 544	$ 937
Completed Technology
Finite-Lived Intangible Assets [Line Items]
Amortization expense of intangible assets	125	322
Customer Contracts
Finite-Lived Intangible Assets [Line Items]
Amortization expense of intangible assets	419	571
Noncompete Agreements
Finite-Lived Intangible Assets [Line Items]
Amortization expense of intangible assets	$ 0	$ 44