Employee 401(k) Profit Sharing Plans - Additional Information (Detail) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Compensation And Retirement Disclosure [Abstract]
Duration of profit sharing plan	90 days
Introductory period of profit sharing	April 1 or October 1
Employees eligibility age for participating in profit sharing plan	21 years
Total participants contributions in Profit sharing plan	50.00%
Maximum of each participants compensation	6.00%
Contribution under the Profit sharing plan	$ 6.1	$ 5.0	$ 2.7