Note 2 - Convertible Debentures (Details Textual) - USD ($)				1 Months Ended			3 Months Ended			6 Months Ended	9 Months Ended
	Feb. 29, 2016	Feb. 16, 2016	Aug. 31, 2015	Feb. 29, 2016	Feb. 29, 2016	Aug. 31, 2015	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015	Dec. 31, 2015	Mar. 31, 2016	Mar. 31, 2015	Jun. 30, 2015
Convertible Debt [Member] | Debt Issuance Cost Allocated to Debt [Member]
Debt Issuance Costs, Net	$ 183,000			$ 183,000	$ 183,000
Convertible Debt [Member] | Debt Issuance Cost Allocated to Equity [Member]
Debt Issuance Costs, Net	37,000			37,000	37,000
Convertible Debt [Member]
Debt Instrument, Face Amount	$ 12,500,000			$ 12,500,000	$ 12,500,000
Debt Conversion, Convertible Shares	3,676,471			3,676,471	3,676,471
Debt Instrument, Term					3 years
Debt Instrument, Interest Rate, Stated Percentage	22.00%			22.00%	22.00%
Debt Instrument, Convertible, Conversion Price	$ 3.40			$ 3.40	$ 3.40
Debt Conversion Convertible Shares, Upon Maturity	6,102,941			6,102,941	6,102,941
Proceeds from Convertible Debt					$ 12,319,000
Warrants Not Settleable in Cash, Fair Value Disclosure	$ 4,434,000			$ 4,434,000	4,434,000
Convertible Debt	1,061,000			1,061,000	1,061,000
Debt Instrument, Unamortized Discount	11,258,000			11,258,000	11,258,000
Amortization of Debt Discount (Premium)							$ 469,000
Amortization of Debt Issuance Costs							8,000
Interest Expense							344,000
Debt Instrument, Debt Default, Amount							0				$ 0
Debentures, Beneficial Conversion Feature [Member]
Debt Instrument, Convertible, Beneficial Conversion Feature					$ 6,824,000
Thirty-Year Debentures [Member] | Series A Warrant [Member]
Residual Fair Value of Warrants			$ 3,385,000
Thirty-Year Debentures [Member] | Series B Warrant [Member]
Residual Fair Value of Warrants			$ 897,000
Class of Warrant or Right, Cancelled During Period,Value							159,000
Thirty-Year Debentures [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights			1,102,942			1,102,942
Debt Instrument, Term			30 years
Proceeds from Convertible Debt			$ 4,720,000
Convertible Debt			0			$ 0
Debt Instrument, Unamortized Discount			4,720,000			4,720,000
Amortization of Debt Discount (Premium)		$ 4,648,000					4,668,000				4,720,000
Amortization of Debt Issuance Costs		765,000					768,000				778,000
Potential Proceed from Issuance of Convertible Debt						15,000,000
Gross Proceeds from Convertible Debt						5,500,000	5,500,000
Registration Payment Arrangement, Gains and Losses											$ 1,100,000
Registration Payment								$ 220,000
Repayments of Debt				$ 7,500,000			7,500,000
Gain (Loss) on Extinguishment of Debt							$ (795,000)
Payment After Approval of Authorities [Member]
Potential Proceed from Issuance of Convertible Debt						$ 9,500,000
Thirty-Year Debentures, Beneficial Conversion Feature [Member]
Debt Instrument, Convertible, Beneficial Conversion Feature			$ 438,000
Warrants [Member]
Fair Value Assumptions, Expected Term					5 years
Fair Value Assumptions, Expected Volatility Rate					91.00%
Fair Value Inputs, Discount Rate					1.20%
Series A Warrant [Member] | Other Expense [Member]
Derivative, Gain (Loss) on Derivative, Net	$ (149,000)
Series A Warrant [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 8		$ 13.60	$ 8	$ 8	$ 13.60
Warrant Expiration Period						5 years 182 days
Fair Value Assumptions, Expected Term	5 years
Fair Value Assumptions, Expected Volatility Rate	91.00%
Fair Value Inputs, Discount Rate	1.20%
Class of Warrant or Right, Outstanding			404,412			404,412	404,412				404,412
Fair Value Assumptions, Expected Dividend Rate	0.00%
Series B Warrant [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights			606,618			606,618
Class of Warrant or Right, Exercise Price of Warrants or Rights			$ 13.60			$ 13.60
Warrant Expiration Period						1 year 180 days
Fair Value Assumptions, Expected Term										1 year 73 days
Fair Value Assumptions, Expected Volatility Rate										88.00%
Fair Value Inputs, Discount Rate										0.57%
Warrants Not Settleable in Cash, Fair Value Disclosure		$ 25,000						$ 33,000		$ 33,000
Class of Warrant or Right, Outstanding			222,427			222,427	222,427				222,427
Fair Value Assumptions, Expected Dividend Rate										0.00%
Shares Issued for Cashless Exercise of Warrants		125,000						106,711
Class of Warrant or Right, Cancelled During Period,Value		$ 159,000
Gross Proceeds from Financing Transaction					$ 15,000,000
Stock Issued During Period, Shares, New Issues					735,294
Sale of Stock, Price Per Share	$ 3.40			$ 3.40	$ 3.40
Stock Issued During Period, Value, New Issues					$ 2,500
Class of Warrant or Right, Number of Securities Called by Warrants or Rights	3,529,412			3,529,412	3,529,412
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 8			$ 8	$ 8
Warrant Expiration Period					5 years
Number of Warrants, Percentage of Shares Issued or to Be Issued					80.00%
Debt Issuance Costs, Net	$ 220,000			$ 220,000	$ 220,000		$ 176,000				$ 176,000		$ 0
Period after Benchmark Reached					15 days
Net Cash and Short-Term Investment Benchmark	$ 2,100,000			$ 2,100,000	$ 2,100,000
Duration of Moving Average Price					20 days
Percent of Stock Price					125.00%
Consecutive Days of Weighted Average Trading Price					10 days
Share Price	$ 4			$ 4	$ 4
Fair Value Assumptions, Expected Term											5 years
Fair Value Assumptions, Expected Volatility Rate											79.00%
Proceeds from Convertible Debt											$ 18,000,000
Convertible Debt							1,535,000				1,535,000
Debt Instrument, Unamortized Discount							$ 10,789,000				10,789,000
Amortization of Debt Discount (Premium)											5,189,000
Amortization of Debt Issuance Costs											785,000
Approval for Grant in Amount for Clinical Trial			$ 10,000,000			$ 10,000,000
Registration Payment Arrangement, Gains and Losses											$ (1,100,000)
Fair Value Assumptions, Expected Dividend Rate											0.00%
Derivative, Gain (Loss) on Derivative, Net							$ (454,000)				$ 3,152,000
Gain (Loss) on Extinguishment of Debt							$ (795,000)				$ (795,000)