Note 7 - Exercise Price Range Relating to Oustanding and Exercisable Options (Details)	3 Months Ended
	Sep. 30, 2015 $ / shares shares
Range One [Member]
Exercise Price Range, Lower Limit (in dollars per share)	$ 1.95
Exercise Price Range, Upper Limit (in dollars per share)	$ 2.45
Outstanding, Number of Shares (in shares) | shares	1,399,500
Outstanding, Weighted Average Remaining Contractual Life	8 years 343 days
Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 2.39
Exercisable, Number of Shares (in shares) | shares	45,000
Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 2.26
Range Two [Member]
Exercise Price Range, Lower Limit (in dollars per share)	2.47
Exercise Price Range, Upper Limit (in dollars per share)	$ 2.85
Outstanding, Number of Shares (in shares) | shares	1,317,500
Outstanding, Weighted Average Remaining Contractual Life	6 years 251 days
Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 2.55
Exercisable, Number of Shares (in shares) | shares	144,168
Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 2.75
Range Three [Member]
Exercise Price Range, Lower Limit (in dollars per share)	3.14
Exercise Price Range, Upper Limit (in dollars per share)	$ 4.07
Outstanding, Number of Shares (in shares) | shares	1,166,590
Outstanding, Weighted Average Remaining Contractual Life	7 years 76 days
Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 4.04
Exercisable, Number of Shares (in shares) | shares	763,561
Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 4.05
Range Four [Member]
Exercise Price Range, Lower Limit (in dollars per share)	4.15
Exercise Price Range, Upper Limit (in dollars per share)	$ 39.60
Outstanding, Number of Shares (in shares) | shares	519,694
Outstanding, Weighted Average Remaining Contractual Life	4 years 299 days
Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 18.90
Exercisable, Number of Shares (in shares) | shares	363,444
Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 24.94
Outstanding, Number of Shares (in shares) | shares	4,403,284
Outstanding, Weighted Average Remaining Contractual Life	7 years 116 days
Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 4.83
Exercisable, Number of Shares (in shares) | shares	1,316,173
Exercisable, Weighted Average Exercise Price (in dollars per share)	$ 9.61