Quarterly report pursuant to Section 13 or 15(d)

Share-Based Payments - Stock Option Activity (Details)

v3.19.3
Share-Based Payments - Stock Option Activity (Details)
$ / shares in Units, shares in Thousands, $ in Thousands
 9 Months Ended
Sep. 30, 2019
USD ($)
$ / shares
shares
Sep. 30, 2018
USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Share-based compensation expense $ 9,006 $ 7,525
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 (45)  
Forfeited (in shares) | shares (8)  
Outstanding, end of period (in shares) | shares 485  
Exercisable, end of period (in shares) | shares 319  
Outstanding, beginning of period (in dollars per share) | $ / shares $ 51  
Exercises in Period (in dollars per share) | $ / shares 47  
Forfeited in period (in dollars per share) | $ / shares 54  
Outstanding, end of period (in dollars per share) | $ / shares 52  
Exercisable, end of period (in dollars per share) | $ / shares $ 48  
Aggregate Intrinsic Value Outstanding, end of period $ 4,638  
Aggregate Intrinsic Value Exercisable, end of period $ 4,163  
Weighted-average remaining contractual term Outstanding, end of period (in years) 4 years  
Weighted-average remaining contractual term Exercisable, end of period (in years) 3 years 3 months 18 days  
Share-based compensation expense $ 1,209 1,085
Tax benefit related to share-based expense 312 271
Unrecognized share-based compensation, net of estimated forfeitures $ 1,878 $ 3,621
Weighted average period over which unrecognized compensation will be recognized (years) 1 year 7 months 6 days