Note 7 - Share-based Compensation (Details) - Weighted Average Assumptions (USD $)
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Weighted Average Assumptions [Abstract]      
Weighted average grant-date fair value per stock option $US (in Dollars per share) $ 1.24 $ 1.26 $ 3.41
Expected volatility 78.67% 86.53% 84.68%
Risk-free interest rate 1.65% 1.90% 0.89%
Expected life of options in years 5 years 299 days 6 years 6 years