Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Jun. 30, 2017	Jun. 30, 2016
Allowance for doubtful accounts	$ 946	$ 887
Common Class A [Member]
Common stock, authorized (in shares)	20,000,000	20,000,000
Common stock, outstanding (in shares)	6,267,603	6,249,563
Common stock, par value (in dollars per share)	$ 1	$ 1
Common Class B [Member]
Common stock, authorized (in shares)	10,000,000	10,000,000
Common stock, outstanding (in shares)	761,588	772,742
Common stock, par value (in dollars per share)	$ 1	$ 1