Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Jun. 30, 2023	Jun. 30, 2022
Allowance for doubtful accounts	$ 449	$ 796
Class A
Common stock, shares issued (in shares)	8,265,033	8,096,279
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares authorized (in shares)	20,000,000	20,000,000
Common stock, shares, outstanding (in shares)	6,853,673	6,682,521
Class B
Common stock, shares issued (in shares)	875,192	905,193
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares authorized (in shares)	10,000,000	10,000,000
Common stock, shares, outstanding (in shares)	576,396	610,087