Consolidated Balance Sheets (Parentheticals) - USD ($)	Jun. 30, 2022	Jun. 30, 2021
Accounts receivable, allowance for doubtful accounts	$ 3,383	$ 3,527
Preferred stock par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	500,000	500,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	20,000,000	20,000,000
Common stock, shares issued (in shares)	6,129,611	6,436,568
Common stock, shares outstanding (in shares)	6,129,611	6,436,568
Treasury stock, shares (in shares)	3,061,795	2,567,797