Note 3 - Stock-based Compensation - Stock Option Activity by Exercise Price Range (Details)	3 Months Ended
	Sep. 30, 2016 $ / shares shares
Range of Exercise prices, lower range limit (in dollars per share)	$ 16
Range of Exercise prices, upper range limit (in dollars per share)	$ 16
Options Outstanding, Number Outstanding (in shares) | shares	10,000
Options Outstanding, Weighted Average Remaining Contractual Life	5 years 302 days
Options Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 16
Options Exercisable, Number Exercisable (in shares) | shares	8,000
Options Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 16