Accrued Expenses - Accrued Expenses (Detail) - USD ($)	Sep. 30, 2021	Sep. 30, 2020
Payables and Accruals [Abstract]
Payroll and related accruals	$ 1,735,000	$ 1,608,000
Warranty and related accruals	291,000	299,000
Property tax accruals	223,000	180,000
Income tax accruals	224,000	225,000
Professional fees	105,000	247,000
Other	67,000	46,000
Accrued expenses	$ 2,645,000	$ 2,605,000