XML 31 R21.htm IDEA: XBRL DOCUMENT v3.7.0.1
Note 5 - Accounting for Stock-based Compensation - Valuation Assumptions (Details) - $ / shares
3 Months Ended 6 Months Ended
Jun. 30, 2017
Jun. 30, 2016
Jun. 30, 2017
Jun. 30, 2016
Weighted average grant date fair value (in dollars per share) $ 0.26 $ 0.29 $ 0.26 $ 0.29
Weighted average assumptions used:        
Expected dividend yield 0.00% 0.00% 0.00% 0.00%
Risk-free interest rate 1.77% 1.38% 1.77% 1.38%
Expected volatility 75.00% 96.00% 75.00% 96.00%
Expected life (in years) (Year) 5 years 5 years 5 years 5 years