Income Taxes - Deferred Income Tax Assets and Liabilities (Detail) - USD ($)	Sep. 30, 2022	Sep. 30, 2021
Deferred Tax Assets:
Accrued liabilities and reserves	$ 155,000	$ 276,000
Allowance for doubtful accounts	83,000	72,000
Inventory	3,197,000	1,783,000
Stock-based compensation	0	79,000
Unrealized loss on investments	1,272,000	0
Net operating losses carryforwards	352,000	20,000
Gross Deferred Income Tax Assets	5,059,000	2,230,000
Deferred and Other Tax Liabilities:
Domestic international sales corporation	(136,000)	(236,000)
Property and equipment	(1,868,000)	(1,943,000)
Unrealized gain on investments	0	(295,000)
Unrecognized tax benefits	(131,000)	(150,000)
Gross Deferred and Other Income Tax Liabilities	(2,135,000)	(2,624,000)
Gross Deferred and Other Income Tax Liabilities	$ 2,924,000	$ (394,000)