Note 12 - Equity Transaction and Stock-based Compensation - Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range (Details) - $ / shares	12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2015
Weighted Average Exercise Price, Outstanding (in dollars per share)	$ 0.29	$ 0.40	$ 0.52
Weighted Average Remaining Contractual Life (Year)	5 years 219 days
Exercisable (in shares)	2,506,683	2,383,617
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 0.30	$ 0.46
Range of Exercise Price, Lower Limit (in dollars per share)	0.09
Range of Exercise Price, Upper Limit (in dollars per share)	$ 3.36
Outstanding (in shares)	2,718,183	2,870,950	3,072,950
Range One [Member]
Weighted Average Exercise Price, Outstanding (in dollars per share)	$ 0.09
Weighted Average Remaining Contractual Life (Year)	7 years 292 days
Exercisable (in shares)	1,744,833
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 0.09
Range of Exercise Price, Lower Limit (in dollars per share)	0.09
Range of Exercise Price, Upper Limit (in dollars per share)	$ 0.10
Outstanding (in shares)	1,956,333
Range Two [Member]
Weighted Average Exercise Price, Outstanding (in dollars per share)	$ 0.14
Weighted Average Remaining Contractual Life (Year)	1 year 182 days
Exercisable (in shares)	448,750
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 0.14
Range of Exercise Price, Lower Limit (in dollars per share)	0.14
Range of Exercise Price, Upper Limit (in dollars per share)	$ 0.15
Outstanding (in shares)	448,750
Range Three [Member]
Weighted Average Exercise Price, Outstanding (in dollars per share)	$ 0.24
Weighted Average Remaining Contractual Life (Year)	9 years 146 days
Exercisable (in shares)	150,000
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 0.24
Range of Exercise Price, Lower Limit (in dollars per share)	0.23
Range of Exercise Price, Upper Limit (in dollars per share)	$ 0.25
Outstanding (in shares)	150,000
Range Four [Member]
Weighted Average Exercise Price, Outstanding (in dollars per share)	$ 3.05
Weighted Average Remaining Contractual Life (Year)	146 days
Exercisable (in shares)	158,600
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 3.05
Range of Exercise Price, Lower Limit (in dollars per share)	3.05
Range of Exercise Price, Upper Limit (in dollars per share)	$ 3.05
Outstanding (in shares)	158,600
Range Five [Member]
Weighted Average Exercise Price, Outstanding (in dollars per share)	$ 3.36
Weighted Average Remaining Contractual Life (Year)	146 days
Exercisable (in shares)	4,500
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 3.36
Range of Exercise Price, Lower Limit (in dollars per share)	3.36
Range of Exercise Price, Upper Limit (in dollars per share)	$ 3.36
Outstanding (in shares)	4,500