Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Jun. 30, 2021	Jun. 30, 2020
Allowance for doubtful accounts	$ 665	$ 736
Common Stock, Par or Stated Value Per Share	$ 1	$ 1
Class A
Common Stock, Shares, Outstanding	6,475,307	6,308,205
Common Stock, Shares Authorized	20,000,000	20,000,000
Class B
Common Stock, Shares, Outstanding	633,505	679,680
Common Stock, Shares Authorized	10,000,000	10,000,000
Common Stock, Par or Stated Value Per Share	$ 1	$ 1