Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Sep. 30, 2020	Jun. 30, 2020
Allowance for doubtful accounts	$ 597	$ 736
Class A
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)	6,342,031	6,308,025
Class B
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)	651,816	679,680