Quarterly report pursuant to Section 13 or 15(d)

Note 9 - Summary of Stock Options - Summary of Options Outstanding and Exercisable (Details)

v3.8.0.1
Note 9 - Summary of Stock Options - Summary of Options Outstanding and Exercisable (Details)
9 Months Ended
Sep. 30, 2017
$ / shares
shares
Options outstanding, number (in shares) | shares 2,489,979
Options outstanding, weighted average exercise price (in dollars per share) $ 5.88
Options outstanding, weighted average remaining contractual term (Year) 8 years 255 days
Options exercisable, number exercisable (in shares) | shares 734,721
Options exercisable, weighted average exercise price (in dollars per share) $ 5.90
Range One [Member]  
Options outstanding, number (in shares) | shares 12,500
Options outstanding, weighted average exercise price (in dollars per share) $ 2.64
Options outstanding, weighted average remaining contractual term (Year) 7 years 226 days
Options exercisable, number exercisable (in shares) | shares 7,553
Options exercisable, weighted average exercise price (in dollars per share) $ 2.64
Range Two [Member]  
Options outstanding, number (in shares) | shares 66,876
Options outstanding, weighted average exercise price (in dollars per share) $ 3.76
Options outstanding, weighted average remaining contractual term (Year) 7 years 127 days
Options exercisable, number exercisable (in shares) | shares 43,191
Options exercisable, weighted average exercise price (in dollars per share) $ 3.76
Exercise price range, lower limit (in dollars per share) 3.68
Exercise price range, upper limit (in dollars per share) $ 3.76
Range Three [Member]  
Options outstanding, number (in shares) | shares 400,329
Options outstanding, weighted average exercise price (in dollars per share) $ 4.63
Options outstanding, weighted average remaining contractual term (Year) 8 years 91 days
Options exercisable, number exercisable (in shares) | shares 161,941
Options exercisable, weighted average exercise price (in dollars per share) $ 4.77
Exercise price range, lower limit (in dollars per share) 4.46
Exercise price range, upper limit (in dollars per share) $ 4.92
Range Four [Member]  
Options outstanding, number (in shares) | shares 567,679
Options outstanding, weighted average exercise price (in dollars per share) $ 5.22
Options outstanding, weighted average remaining contractual term (Year) 9 years 73 days
Options exercisable, number exercisable (in shares) | shares 108,555
Options exercisable, weighted average exercise price (in dollars per share) $ 5.22
Range Five [Member]  
Options outstanding, number (in shares) | shares 254,000
Options outstanding, weighted average exercise price (in dollars per share) $ 5.62
Options outstanding, weighted average remaining contractual term (Year) 9 years 339 days
Options exercisable, number exercisable (in shares) | shares
Options exercisable, weighted average exercise price (in dollars per share)
Exercise price range, lower limit (in dollars per share) 5.58
Exercise price range, upper limit (in dollars per share) $ 5.67
Range Six [Member]  
Options outstanding, number (in shares) | shares 557,753
Options outstanding, weighted average exercise price (in dollars per share) $ 6
Options outstanding, weighted average remaining contractual term (Year) 8 years 80 days
Options exercisable, number exercisable (in shares) | shares 244,023
Options exercisable, weighted average exercise price (in dollars per share) $ 6
Range Seven [Member]  
Options outstanding, number (in shares) | shares 150,639
Options outstanding, weighted average exercise price (in dollars per share) $ 6.44
Options outstanding, weighted average remaining contractual term (Year) 8 years 76 days
Options exercisable, number exercisable (in shares) | shares 45,574
Options exercisable, weighted average exercise price (in dollars per share) $ 6.34
Exercise price range, lower limit (in dollars per share) 6.24
Exercise price range, upper limit (in dollars per share) $ 6.61
Range Eight [Member]  
Options outstanding, number (in shares) | shares 441,825
Options outstanding, weighted average exercise price (in dollars per share) $ 7.65
Options outstanding, weighted average remaining contractual term (Year) 9 years 36 days
Options exercisable, number exercisable (in shares) | shares 85,506
Options exercisable, weighted average exercise price (in dollars per share) $ 7.72
Exercise price range, lower limit (in dollars per share) 7
Exercise price range, upper limit (in dollars per share) $ 7.92
Range Nine [Member]  
Options outstanding, number (in shares) | shares 38,135
Options outstanding, weighted average exercise price (in dollars per share) $ 9.92
Options outstanding, weighted average remaining contractual term (Year) 5 years 51 days
Options exercisable, number exercisable (in shares) | shares 38,135
Options exercisable, weighted average exercise price (in dollars per share) $ 9.92
Range Ten [Member]  
Options outstanding, number (in shares) | shares 243
Options outstanding, weighted average exercise price (in dollars per share) $ 100.46
Options outstanding, weighted average remaining contractual term (Year) 3 years 76 days
Options exercisable, number exercisable (in shares) | shares 243
Options exercisable, weighted average exercise price (in dollars per share) $ 100.46
Exercise price range, lower limit (in dollars per share) 56
Exercise price range, upper limit (in dollars per share) $ 296