Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Sep. 30, 2021	Jun. 30, 2021
Allowance for doubtful accounts	$ 647	$ 665
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)	6,619,304	6,475,307
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)	607,032	633,505