Annual report pursuant to Section 13 and 15(d)

Stock Option Plans (Summary of Stock Option Activity) (Detail)

v3.19.1
Stock Option Plans (Summary of Stock Option Activity) (Detail) - $ / shares
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Number of Options outstanding        
Outstanding, Beginning Balance 1,510,244 1,084,298    
Outstanding, Ending Balance 1,546,521 1,510,244 1,084,298  
Employee Stock Option [Member]        
Number of Options outstanding        
Outstanding, Beginning Balance 1,510,244 1,084,298 1,022,789  
Granted 330,500 534,500 116,750  
Exercised (97,264) (63,187) (10,450)  
Expired or Forfeited (196,959) (45,367) (44,791)  
Outstanding, Ending Balance 1,546,521 1,510,244 1,084,298 1,022,789
Weighted Average Exercise Price        
Outstanding, Beginning Balance $ 5.04 $ 4.76 $ 4.59  
Granted 5.81 5.74 6.60  
Exercised 4.96 2.89 3.46  
Expired or Forfeited 6.11 8.30 3.87  
Outstanding, Ending Balance $ 5.11 $ 5.04 $ 4.76 $ 4.59
Weighted Average Remaining Life (Years)        
Options Outstanding, Weighted Average Remaining Life (Years) 7 years 2 months 8 days 7 years 6 months 29 days 7 years 6 months 25 days 7 years 6 months 22 days