Note 3 - Stock-based Compensation - Stock Option Activity (Details) - $ / shares	3 Months Ended	9 Months Ended
	Mar. 31, 2017	Mar. 31, 2017	Mar. 31, 2016
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	0
Granted (in dollars per share)		$ 0	$ 0
Options outstanding at end of period (in shares)	10,000	10,000	10,000
Options outstanding at end of period (in dollars per share)	$ 16	$ 16	$ 16
Options exercisable at end of period (in shares)	8,000	8,000	6,000
Options exercisable at end of period (in dollars per share)	$ 0	$ 0	$ 0