Income Taxes - Provision for Income Tax Expense (Detail) - USD ($)	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Current:
Federal	$ 992,000	$ 3,430,000
State	189,000	346,000
Total current	1,181,000	3,776,000
Deferred:
Federal	(269,000)	(2,436,000)
State	(83,000)	(190,000)
Total deferred	(352,000)	(2,626,000)
Income tax expense	$ 829,000	$ 1,150,000