Quarterly report pursuant to Section 13 or 15(d)

Note 6 - Stock Option Plans - Summary of Option Activity for Employees and Non-employees (Details)

v3.7.0.1
Note 6 - Stock Option Plans - Summary of Option Activity for Employees and Non-employees (Details) - USD ($)
3 Months Ended 12 Months Ended
Mar. 31, 2017
Dec. 31, 2016
Employee Stock Option [Member]    
Number of options (in shares) 1,511,995  
Weighted average exercise price, outstanding (in dollars per share) $ 1.74  
Weighted average remaining contractual life, outstanding (Year) 3 years 51 days 2 years 354 days
Aggregate intrinsic value, outstanding $ 5.469
Number of options granted (in shares) 211,179  
Weighted average exercise price, granted (in dollars per share) $ 1.64  
Weighted average remaining contractual life, granted (Year) 4 years 284 days  
Number of options exercised (in shares) (83,333)  
Weighted average exercise price, exercised (in dollars per share) $ 0.75  
Weighted average remaining contractual life, exercised (Year)  
Number of options forfeited and expired (in shares) 1,639,841 1,511,995
Weighted average exercise price, forfeited or expired (in dollars per share) $ 1.75  
Weighted average exercise price, outstanding (in dollars per share) $ 1.87 $ 1.74
Number of options exercisable (in shares) 1,118,096  
Weighted average exercise price, exercisable (in dollars per share) $ 1.84  
Weighted average remaining contractual life, exercisable (Year) 2 years 255 days  
Aggregate intrinsic value, exercisable  
Non-employee Options [Member]    
Number of options (in shares) 224,999  
Weighted average exercise price, outstanding (in dollars per share) $ 2.53  
Weighted average remaining contractual life, outstanding (Year) 5 years 43 days 5 years 116 days
Aggregate intrinsic value, outstanding
Number of options granted (in shares)  
Weighted average exercise price, granted (in dollars per share)  
Weighted average remaining contractual life, granted (Year)  
Number of options exercised (in shares)  
Weighted average exercise price, exercised (in dollars per share)  
Weighted average remaining contractual life, exercised (Year)  
Number of options forfeited and expired (in shares) 224,999 224,999
Weighted average exercise price, forfeited or expired (in dollars per share)  
Weighted average exercise price, outstanding (in dollars per share) $ 2.53 $ 2.53
Number of options exercisable (in shares) 10,183  
Weighted average exercise price, exercisable (in dollars per share) $ 2.33  
Weighted average remaining contractual life, exercisable (Year) 5 years 25 days  
Aggregate intrinsic value, exercisable  
Number of options forfeited and expired (in shares)