Summary of Significant Accounting Policies and Supplemental Balance Sheet Information - Summary of Other Noncurrent Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2023	Sep. 30, 2022
Schedule of Investments [Line Items]
Other assets, net	$ 3,864	$ 4,769
Operating Lease Right-of-Use Assets [Member]
Schedule of Investments [Line Items]
Other assets, net	2,987	3,633
Other [Member]
Schedule of Investments [Line Items]
Other assets, net	$ 877	$ 1,136