Note 7 - Equity - Warrant Activity (Details) - Warrant [Member] - USD ($)	3 Months Ended	12 Months Ended
	Sep. 30, 2018	Jun. 30, 2018
Warrants outstanding (in shares)	3,458,826
Warrants outstanding, weighted average exercise price per share (in dollars per share)	$ 3.65
Warrants outstanding, weighted average remaining contractual life (Year)	3 years 109 days	3 years 149 days
Warrants outstanding, aggregate intrinsic value
Warrants issued (in shares)
Warrants issued, weighted average exercise price per share (in dollars per share)
Warrants expired (in shares)	(61,112)
Warrants expired, weighted average exercise price per share (in dollars per share)	$ 11.69
Warrants outstanding (in shares)	3,397,714	3,458,826
Warrants outstanding, weighted average exercise price per share (in dollars per share)	$ 3.25	$ 3.65
Warrants exercisable (in shares)	3,397,714
Warrants exercisable, weighted average exercise price per share (in dollars per share)	$ 3.25
Warrants exercisable, weighted average remaining contractual life (Year)	3 years 171 days
Warrants exercisable, aggregate intrinsic value