Quarterly report pursuant to Section 13 or 15(d)

Share-Based Payments - Stock Option Activity (Details)

v3.19.2
Share-Based Payments - Stock Option Activity (Details)
$ / shares in Units, shares in Thousands, $ in Thousands
6 Months Ended
Jun. 30, 2019
USD ($)
$ / shares
shares
Jun. 30, 2018
USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Share-based compensation expense $ 6,244 $ 4,678
Employee Stock Option [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Stock option grants expire (in years) 7 years  
Grants, vesting period (in years) 3 years  
Outstanding, beginning of period (in shares) | shares 538  
Exercised (in shares) | shares (27)  
Outstanding, end of period (in shares) | shares 511  
Exercisable, end of period (in shares) | shares 299  
Outstanding, beginning of period (in dollars per share) | $ / shares $ 51  
Exercises in Period (in dollars per share) | $ / shares 47  
Outstanding, end of period (in dollars per share) | $ / shares 52  
Exercisable, end of period (in dollars per share) | $ / shares $ 46  
Aggregate Intrinsic Value Outstanding, end of period $ 4,970  
Aggregate Intrinsic Value Exercisable, end of period $ 4,508  
Weighted-average remaining contractual term Outstanding, end of period (in years) 4 years 2 months 12 days  
Weighted-average remaining contractual term Exercisable, end of period (in years) 3 years 2 months 12 days  
Share-based compensation expense $ 850 688
Tax benefit related to share-based expense 217 172
Unrecognized share-based compensation, net of estimated forfeitures $ 2,358 $ 2,243
Weighted average period over which unrecognized compensation will be recognized (years) 1 year 8 months 12 days