Quarterly report pursuant to Section 13 or 15(d)

Note 6 - Employee and Director Benefits - Summary of Stock Option Activity (Details)

v3.8.0.1
Note 6 - Employee and Director Benefits - Summary of Stock Option Activity (Details) - Employee Stock Option [Member] - USD ($)
$ / shares in Units, $ in Thousands
 9 Months Ended 12 Months Ended
Sep. 30, 2017
Sep. 30, 2016
Dec. 31, 2016
Dec. 31, 2015
Outstanding (in shares) 2,026,334 2,498,834 2,498,834  
Outstanding, weighted average exercise price (in dollars per share) $ 9 $ 6.66 $ 6.66  
Outstanding, weighted average remaining contractual term (Year) 5 years 255 days 6 years 182 days 6 years 73 days 6 years 109 days
Outstanding, aggregate intrinsic value $ 45,136 $ 35,277 $ 57,636 $ 42,743
Granted (in shares) 52,500 234,000    
Granted, weighted average exercise price (in dollars per share) $ 37.93 $ 19.98    
Granted, weighted average remaining contractual term (Year) 9 years 146 days 9 years 182 days    
Granted, aggregate intrinsic value $ (35) $ 1,398    
Exercised (in shares) (359,000) (656,500)    
Exercised, weighted average exercise price (in dollars per share) $ 4.97 $ 4.25    
Exercised, weighted average remaining contractual term (Year) 4 years 73 days 4 years 73 days    
Exercised, aggregate intrinsic value $ 11,590 $ 14,254    
Forfeited (in shares) (32,000) (13,000)    
Forfeited, weighted average exercise price (in dollars per share) $ 21.96 $ 19.41    
Forfeited, weighted average remaining contractual term (Year) 8 years 146 days 9 years    
Forfeited, aggregate intrinsic value $ 489 $ 85    
Outstanding (in shares) 1,687,834 2,063,334 2,026,334 2,498,834
Outstanding, weighted average exercise price (in dollars per share) $ 10.51 $ 8.86 $ 9 $ 6.66
Exercisable (in shares) 810,736 594,536    
Exercisable, weighted average exercise price (in dollars per share) $ 5.22 $ 6.45    
Exercisable, weighted average remaining contractual term (Year) 4 years 73 days 6 years    
Exercisable, aggregate intrinsic value $ 25,971 $ 13,901