Note 11 - Stock-based Compensation (Details) - Fair Value Option Grant Weighted Average Assumptions Using Black-Scholes Option Pricing Model
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Fair Value Option Grant Weighted Average Assumptions Using Black-Scholes Option Pricing Model [Abstract]      
Risk-free interest rate   1.41% 1.32%
Expected life (in years)   6 years 3 months 6 years 80 days
Dividend yield         
Expected volatility   50.00% 50.00%