Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ in Thousands	Mar. 31, 2018	Jun. 30, 2017
Allowance for doubtful accounts	$ 1,164	$ 946
Common Class A [Member]
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, authorized (in shares)	20,000,000	20,000,000
Common stock, outstanding (in shares)	6,272,716	6,267,603
Common Class B [Member]
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, authorized (in shares)	10,000,000	10,000,000
Common stock, outstanding (in shares)	745,216	761,588