Note 3 - Stock-based Compensation - Stock Option Activity (Details) - $ / shares	3 Months Ended
	Sep. 30, 2016	Sep. 30, 2015
Options outstanding at beginning of period (in shares)	10,000	10,000
Options outstanding at beginning of period (in dollars per share)	$ 16	$ 16
Exercised (in shares)	0	0
Exercised (in dollars per share)	$ 0	$ 0
Granted (in shares)	0	0
Granted (in dollars per share)	$ 0	$ 0
Options outstanding at end of period (in shares)	10,000	10,000
Options outstanding at end of period (in dollars per share)	$ 16	$ 16
Options exercisable at end of period (in shares)	8,000	6,000
Options exercisable at end of period (in dollars per share)	$ 0	$ 0