Nature of Operations and Summary of Significant Accounting Policies - Schedule of Changes in Allowance for Credit Losses (Detail) - USD ($)	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024
Receivables [Abstract]
Balance, beginning of year	$ 390,000	$ 545,000
Provision for credit losses	50,000	0
Provision for estimated returns and allowances	395,000	155,000
Uncollectible accounts written off	(63,000)	(20,000)
Returns and allowances issued	(338,000)	(290,000)
Balance, end of year	$ 434,000	$ 390,000