Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Dec. 31, 2021	Sep. 30, 2021
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 250	$ 250
Inventory valuation reserves	$ 3,567	$ 3,476
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	30,000,000	30,000,000
Common stock, shares issued (in shares)	13,041,127	12,610,229
Common stock, shares outstanding (in shares)	13,041,127	12,610,229