Income Taxes - Provision for Income Tax Expense (Detail) - USD ($)	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Current:
Federal	$ 2,297,000	$ 1,483,000
State	148,000	130,000
Total current	2,445,000	1,613,000
Deferred:
Federal	52,000	631,000
State	131,000	126,000
Total deferred	183,000	757,000
Income tax expense	$ 2,628,000	$ 2,370,000	[1]

[1] The amounts for the year ended September 30, 2018 have been adjusted to reflect the change in inventory accounting method, as described in Notes 1 and 2 to the Consolidated Financial Statements.