Note 9 - Equity Compensation - Summary of Unvested Stock Options (Details) - $ / shares	12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016
Unvested (in shares)	1,842,127
Unvested (in dollars per share)	$ 3.52
Granted (in shares)	794,537	1,332,623	1,026,800
Granted (in dollars per share)	$ 1.73	$ 3.67	$ 3.64
Vested (in shares)	(942,905)
Vested (in dollars per share)	$ 3.39
Forfeited (in shares)	(219,634)
Forfeited (in dollars per share)	$ 3.43
Unvested (in shares)	1,474,125	1,842,127
Unvested (in dollars per share)	$ 2.65	$ 3.52