Note 12 - Exercise Price Range Relating to Outstanding and Exercisable Options (Details)	12 Months Ended
	Jun. 30, 2016 $ / shares shares
Range One [Member]
Exercise price range, lower limit (in dollars per share)	$ 1.37
Exercise price range, upper limit (in dollars per share)	$ 2.40
Outstanding, number of shares (in shares) | shares	1,948,647
Outstanding, weighted average remaining contractual life	8 years 10 days
Outstanding, weighted average exercise price (in dollars per share)	$ 2.17
Exercisable, number of shares (in shares) | shares	465,007
Exercisable, weighted average exercise price (in dollars per share)	$ 2.38
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	1,257,500
Outstanding, weighted average remaining contractual life	5 years 229 days
Outstanding, weighted average exercise price (in dollars per share)	$ 2.56
Exercisable, number of shares (in shares) | shares	201,250
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)	$ 4.24
Outstanding, number of shares (in shares) | shares	1,299,090
Outstanding, weighted average remaining contractual life	6 years 14 days
Outstanding, weighted average exercise price (in dollars per share)	$ 4.07
Exercisable, number of shares (in shares) | shares	1,196,590
Exercisable, weighted average exercise price (in dollars per share)	$ 4.06
Range Four [Member]
Exercise price range, lower limit (in dollars per share)	6.11
Exercise price range, upper limit (in dollars per share)	$ 39.60
Outstanding, number of shares (in shares) | shares	246,186
Outstanding, weighted average remaining contractual life	3 years 277 days
Outstanding, weighted average exercise price (in dollars per share)	$ 26.81
Exercisable, number of shares (in shares) | shares	216,186
Exercisable, weighted average exercise price (in dollars per share)	$ 29.64
Outstanding, number of shares (in shares) | shares	4,751,423
Outstanding, weighted average remaining contractual life	6 years 229 days
Outstanding, weighted average exercise price (in dollars per share)	$ 4.07
Exercisable, number of shares (in shares) | shares	2,079,033
Exercisable, weighted average exercise price (in dollars per share)	$ 6.22