Consolidated Balance Sheets (Unaudited) (Parentheticals) - USD ($)	Dec. 31, 2021	Sep. 30, 2021
Accounts receivable, allowance for doubtful accounts	$ 250,000	$ 250,000
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	5,000,000	5,000,000
Common stock, shares issued (in shares)	1,805,053	1,805,053
Common stock, treasury shares (in shares)	424,307	424,307