Note 2 - Stockholders' Equity - Black-Scholes Valuation Assumptions (Details)	3 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Minimum [Member]
Risk-free interest rate	0.71%	1.59%
Weighted-average expected term (in years)	4 years 87 days	4 years 302 days
Expected volatility	64.80%	71.00%
Maximum [Member]
Risk-free interest rate	1.50%	1.65%
Weighted-average expected term (in years)	4 years 113 days	4 years 313 days
Expected volatility	65.80%	72.10%