Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Jun. 30, 2021	Jun. 30, 2020
Accounts receivable, allowance for doubtful accounts	$ 3,527	$ 3,240
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 outstanding (in shares)	6,436,568	6,752,372
Treasury stock, shares (in shares)	2,567,797	2,104,305