Nature of Operations and Summary of Significant Accounting Policies - Schedule of Changes in Allowance for Doubtful Accounts (Detail) - USD ($)	12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2015
Receivables [Abstract]
Balance, beginning of year	$ 195,000	$ 357,000	$ 244,000
Provision for doubtful accounts	115,000	105,000	60,000
Provision for estimated returns and allowances	385,000	175,000	170,000
Uncollectible accounts written-off	(16,000)	(89,000)	(46,000)
Returns and allowances issued	(472,000)	(353,000)	(71,000)
Balance, end of year	$ 207,000	$ 195,000	$ 357,000