Note 6 - Fair Value Measurement and Financial Instruments (Details) - Fair Value Assumptions, Stock-based Compensation Liability (USD $)
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Note 6 - Fair Value Measurement and Financial Instruments (Details) - Fair Value Assumptions, Stock-based Compensation Liability [Line Items]    
Stock price at the end of each reporting period $ 0.54 $ 3.70
Stock-based Compensation Liability [Member]    
Note 6 - Fair Value Measurement and Financial Instruments (Details) - Fair Value Assumptions, Stock-based Compensation Liability [Line Items]    
Stock price at the end of each reporting period $ 0.54 $ 3.70
Weighted average exercise price $ 15.83 $ 17.66
Risk-free interest rate 0.88% 1.00%
Volatility 138.38% 94.53%
Dividend yield 0.00% 0.00%
Expected life in years 2 years 178 days 3 years 153 days
Calculated fair value per stock option $ 0.10 $ 1.17