Income Taxes - Schedule of Provision for Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Income Tax Disclosure [Abstract]
Federal	$ 4,183	$ 4,915
State	59	207
Total current taxes	4,242	5,122
Deferred income tax expense	252	(188)
Actual tax expense and effective rate, Amount	$ 4,494	$ 4,934