XML 85 R69.htm IDEA: XBRL DOCUMENT v3.19.1
Stock-Based Compensation - Summary of Stock Option Awards (Detail) - Employee Stock Option - USD ($)
$ / shares in Units, $ in Thousands
 3 Months Ended 12 Months Ended
Mar. 31, 2019
Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]    
Options, Outstanding, Balance (shares) 953,905  
Options, Granted (shares) 0  
Options, Exercised (shares) (32,486)  
Options, Forfeited (shares) 0  
Options, Outstanding, Balance (shares) 921,419 953,905
Options exercisable at end of period (shares) 921,419  
Weighted Average Exercise Price, Outstanding, Balance (in dollars per share) $ 14.58  
Weighted Average Exercise Price, Granted (in dollars per share) 0.00  
Weighted Average Exercise Price, Exercised (in dollars per share) 6.50  
Weighted Average Exercise Price, Forfeited (in dollars per share) 0.00  
Weighted Average Exercise Price, Outstanding, Balance (in dollars per share) 14.87 $ 14.58
Weighted Average Exercise Price, Options exercisable at end of period (in dollars per share) $ 14.87  
Weighted Average Remaining Contractual Life, Outstanding 4 years 1 month 6 days 4 years 2 months 12 days
Weighted Average Remaining Contractual Life, Options exercisable at end of period 4 years 1 month 6 days  
Aggregate Intrinsic Value, Outstanding, Balance $ 350 $ 296
Aggregate Intrinsic Value, Outstanding, Options exercisable at end of period $ 350