Quarterly report pursuant to Section 13 or 15(d)

Note 8 - Summary of Stock Options - Summary of Option Activity Under All Plans (Details)

v3.7.0.1
Note 8 - Summary of Stock Options - Summary of Option Activity Under All Plans (Details)
6 Months Ended 12 Months Ended
Jun. 30, 2017
USD ($)
$ / shares
shares
Dec. 31, 2016
USD ($)
$ / shares
shares
Options outstanding, Shares (in shares) | shares 1,909,764  
Options outstanding, Weighted average exercise price (in dollars per share) | $ / shares $ 6.19  
Options outstanding, Weighted average exercise priceod (in dollars per share) | $ / shares $ 6.15 $ 6.19
Options outstanding, weighted average remaining contractual term (Year) 8 years 299 days 9 years 43 days
Options outstanding, Aggregate Intrinsic Value | $ $ 3,290,039,000 $ 211,396
Options granted, Shares (in shares) | shares 420,985  
Vested and exercisable and expected to vest, end of period, Number Of Shares (in shares) | shares 2,135,320  
Vested and exercisable and expected to vest, end of period, Weighted Average Exercise Price (in dollars per share) | $ / shares $ 6.17  
Vested and exercisable and expected to vest, end of period, Weighted Average Remaining Contractual Term (Year) 8 years 288 days  
Vested and exercisable and expected to vest, end of period, Aggregate Intrinsic Value | $ $ 3,076,175,000  
Options granted, Weighted average exercise price (in dollars per share) | $ / shares $ 5.88  
Options exercised, Shares (in shares) | shares (7,730)  
Options exercised, Weighted average exercise price (in dollars per share) | $ / shares $ 4.02  
Options canceled, Shares (in shares) | shares (35,447)  
Options canceled, Weighted average exercise price (in dollars per share) | $ / shares $ 5.64  
Options outstanding, Shares (in shares) | shares 2,287,572 1,909,764
Vested and exercisable, end of period, Number Of Shares (in shares) | shares 603,985  
Vested and exercisable, end of period, Weighted Average Exercise Price (in dollars per share) | $ / shares $ 6.83  
Vested and exercisable, end of period, Weighted Average Remaining Contractual Term (Year) 7 years 343 days  
Vested and exercisable, end of period, Aggregate Intrinsic Value | $ $ 935,383,000