Nature of Operations and Summary of Significant Accounting Policies - Schedule of Changes in Accrual for Warranty and Related Costs (Detail) - USD ($)	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Product Warranty Liability [Abstract]
Balance, beginning of year	$ 323,000	$ 366,000
Warranties issued	300,000	287,000
Warranties settled	(308,000)	(330,000)
Balance, end of year	$ 315,000	$ 323,000