Quarterly report pursuant to Section 13 or 15(d)

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

v3.10.0.1
Note 9 - Summary of Stock Options - Summary of Options Outstanding and Exercisable (Details)
6 Months Ended
Jun. 30, 2018
$ / shares
shares
Exercise price range, lower limit (in dollars per share)
Exercise price range, upper limit (in dollars per share) $ 2.64
Options outstanding, number (in shares) | shares 4,209,355
Options outstanding, weighted average exercise price (in dollars per share) $ 4.76
Options outstanding, weighted average remaining contractual term (Year) 8 years 292 days
Options exercisable, number exercisable (in shares) | shares 1,124,400
Options exercisable, weighted average exercise price (in dollars per share) $ 5.65
Range One [Member]  
Exercise price range, lower limit (in dollars per share) 1.75
Exercise price range, upper limit (in dollars per share) $ 1.97
Options outstanding, number (in shares) | shares 552,500
Options outstanding, weighted average exercise price (in dollars per share) $ 1.94
Options outstanding, weighted average remaining contractual term (Year) 9 years 328 days
Options exercisable, number exercisable (in shares) | shares 12,500
Options exercisable, weighted average exercise price (in dollars per share) $ 1.97
Range Two [Member]  
Exercise price range, lower limit (in dollars per share) 2.64
Exercise price range, upper limit (in dollars per share) $ 2.72
Options outstanding, number (in shares) | shares 82,500
Options outstanding, weighted average exercise price (in dollars per share) $ 2.67
Options outstanding, weighted average remaining contractual term (Year) 9 years 182 days
Options exercisable, number exercisable (in shares) | shares 9,896
Options exercisable, weighted average exercise price (in dollars per share) $ 2.64
Range Three [Member]  
Exercise price range, lower limit (in dollars per share) 3.11
Exercise price range, upper limit (in dollars per share) $ 3.82
Options outstanding, number (in shares) | shares 319,376
Options outstanding, weighted average exercise price (in dollars per share) $ 3.63
Options outstanding, weighted average remaining contractual term (Year) 9 years 73 days
Options exercisable, number exercisable (in shares) | shares 55,730
Options exercisable, weighted average exercise price (in dollars per share) $ 3.76
Range Four [Member]  
Exercise price range, lower limit (in dollars per share) 4.30
Exercise price range, upper limit (in dollars per share) $ 4.97
Options outstanding, number (in shares) | shares 1,477,533
Options outstanding, weighted average exercise price (in dollars per share) $ 4.52
Options outstanding, weighted average remaining contractual term (Year) 9 years
Options exercisable, number exercisable (in shares) | shares 336,424
Options exercisable, weighted average exercise price (in dollars per share) $ 4.65
Range Five [Member]  
Exercise price range, lower limit (in dollars per share) 5.01
Exercise price range, upper limit (in dollars per share) $ 5.67
Options outstanding, number (in shares) | shares 822,652
Options outstanding, weighted average exercise price (in dollars per share) $ 5.34
Options outstanding, weighted average remaining contractual term (Year) 8 years 255 days
Options exercisable, number exercisable (in shares) | shares 195,456
Options exercisable, weighted average exercise price (in dollars per share) $ 5.22
Range Six [Member]  
Exercise price range, lower limit (in dollars per share) 6
Exercise price range, upper limit (in dollars per share) $ 6.61
Options outstanding, number (in shares) | shares 567,878
Options outstanding, weighted average exercise price (in dollars per share) $ 6.05
Options outstanding, weighted average remaining contractual term (Year) 7 years 219 days
Options exercisable, number exercisable (in shares) | shares 326,724
Options exercisable, weighted average exercise price (in dollars per share) $ 6
Range Seven [Member]  
Exercise price range, lower limit (in dollars per share) 7
Exercise price range, upper limit (in dollars per share) $ 7.92
Options outstanding, number (in shares) | shares 348,538
Options outstanding, weighted average exercise price (in dollars per share) $ 7.65
Options outstanding, weighted average remaining contractual term (Year) 8 years 73 days
Options exercisable, number exercisable (in shares) | shares 149,292
Options exercisable, weighted average exercise price (in dollars per share) $ 7.68
Range Eight [Member]  
Exercise price range, upper limit (in dollars per share)
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) 4 years 146 days
Options exercisable, number exercisable (in shares) | shares 38,135
Options exercisable, weighted average exercise price (in dollars per share) $ 9.92
Range Nine [Member]  
Exercise price range, lower limit (in dollars per share) 59.60
Exercise price range, upper limit (in dollars per share) $ 149.04
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) 2 years 182 days
Options exercisable, number exercisable (in shares) | shares 243
Options exercisable, weighted average exercise price (in dollars per share) $ 100.46