Quarterly report pursuant to Section 13 or 15(d)

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

v3.10.0.1
Stock Based Compensation Plans (Summary of Stock Option Activity) (Detail) - Employee Stock Option [Member]
9 Months Ended
Sep. 30, 2018
$ / shares
shares
Number of Options  
Outstanding, Beginning Balance | shares 1,510,244
Granted | shares 133,500
Exercised | shares (76,354)
Expired or Forfeited | shares (177,527)
Outstanding, Ending Balance | shares 1,389,863
Weighted Average Exercise Price  
Outstanding, Beginning Balance | $ / shares $ 5.04
Granted | $ / shares 5.55
Exercised | $ / shares 5.61
Expired or Forfeited | $ / shares 6.14
Outstanding, Ending Balance | $ / shares $ 4.93