Quarterly report pursuant to Section 13 or 15(d)

Note 8 - Summary of Stock Options - Summary of Options Outstanding and Exercisable (Details)

v3.7.0.1
Note 8 - Summary of Stock Options - Summary of Options Outstanding and Exercisable (Details)
3 Months Ended
Mar. 31, 2017
$ / shares
shares
Options outstanding, number (in shares) | shares 2,134,214
Options outstanding, weighted average exercise price (in dollars per share) $ 6
Options outstanding, weighted average remaining contractual term (Year) 8 years 357 days
Options exercisable, number exercisable (in shares) | shares 501,273
Options exercisable, weighted average exercise price (in dollars per share) $ 7.06
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) 8 years 43 days
Options exercisable, number exercisable (in shares) | shares 5,990
Options exercisable, weighted average exercise price (in dollars per share) $ 2.64
Range Two [Member]  
Options outstanding, number (in shares) | shares 79,376
Options outstanding, weighted average exercise price (in dollars per share) $ 3.75
Options outstanding, weighted average remaining contractual term (Year) 7 years 313 days
Options exercisable, number exercisable (in shares) | shares 41,343
Options exercisable, weighted average exercise price (in dollars per share) $ 3.75
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 427,829
Options outstanding, weighted average exercise price (in dollars per share) $ 4.62
Options outstanding, weighted average remaining contractual term (Year) 8 years 302 days
Options exercisable, number exercisable (in shares) | shares 121,211
Options exercisable, weighted average exercise price (in dollars per share) $ 4.80
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 595,034
Options outstanding, weighted average exercise price (in dollars per share) $ 5.22
Options outstanding, weighted average remaining contractual term (Year) 9 years 270 days
Options exercisable, number exercisable (in shares) | shares 41,748
Options exercisable, weighted average exercise price (in dollars per share) $ 5.22
Range Five [Member]  
Options outstanding, number (in shares) | shares 562,074
Options outstanding, weighted average exercise price (in dollars per share) $ 6
Options outstanding, weighted average remaining contractual term (Year) 8 years 255 days
Options exercisable, number exercisable (in shares) | shares 176,563
Options exercisable, weighted average exercise price (in dollars per share) $ 6
Range Six [Member]  
Options outstanding, number (in shares) | shares 129,267
Options outstanding, weighted average exercise price (in dollars per share) $ 6.35
Options outstanding, weighted average remaining contractual term (Year) 8 years 332 days
Options exercisable, number exercisable (in shares) | shares 36,034
Options exercisable, weighted average exercise price (in dollars per share) $ 6.35
Exercise price range, lower limit (in dollars per share) 6.24
Exercise price range, upper limit (in dollars per share) $ 6.40
Range Seven [Member]  
Options outstanding, number (in shares) | shares 282,219
Options outstanding, weighted average exercise price (in dollars per share) $ 7.71
Options outstanding, weighted average remaining contractual term (Year) 9 years 80 days
Options exercisable, number exercisable (in shares) | shares 32,469
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 Eight [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 237 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]  
Options outstanding, number (in shares) | shares 7,780
Options outstanding, weighted average exercise price (in dollars per share) $ 83.66
Options outstanding, weighted average remaining contractual term (Year) 211 days
Options exercisable, number exercisable (in shares) | shares 7,780
Options exercisable, weighted average exercise price (in dollars per share) $ 83.66
Exercise price range, lower limit (in dollars per share) 56
Exercise price range, upper limit (in dollars per share) $ 296