Condensed Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ in Thousands	Mar. 31, 2024	Jun. 30, 2023
Accounts receivable, allowance for doubtful accounts	$ 0	$ 23
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)	6,200,869	6,073,813
Common stock, shares outstanding (in shares)	6,200,869	6,073,813
Treasury stock, shares (in shares)	3,280,037	3,240,593