Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation (Options) (Details)

v3.19.2
Stock-Based Compensation (Options) (Details) - Stock options - USD ($)
$ / shares in Units, $ in Thousands
 3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2019
Mar. 31, 2019
Jun. 30, 2019
Dec. 31, 2018
Options        
Outstanding at the beginning of the period (in shares) 1,768,350 1,887,969 1,887,969  
Granted (in shares) 0 81,807    
Exercised (in shares) (114,109) (200,326)    
Forfeited (in shares) 0 (1,100)    
Outstanding at the end of the period (in shares) 1,654,241 1,768,350 1,654,241 1,887,969
Options exercisable (in shares) 1,550,570   1,550,570  
Weighted-Average Exercise Price        
Outstanding at the beginning of the period (in dollars per share) $ 21.74 $ 20.05 $ 20.05  
Granted (in dollars per share) 0 49.02    
Exercised (in dollars per share) 13.36 16.91    
Forfeited (in dollars per share) 0 31.70    
Outstanding at the end of the period (in dollars per share) 22.31 $ 21.74 22.31 $ 20.05
Options exercisable (in dollars per share) $ 20.80   $ 20.80  
Weighted-Average Remaining Contractual Life        
Outstanding   3 years 6 months 3 years 4 months 24 days 3 years 4 months 24 days
Options exercisable     3 years 1 month 6 days  
Aggregate Intrinsic Value        
Outstanding (in dollars) $ 76,187 $ 77,197 $ 76,187 $ 56,046
Options exercisable (in dollars) 73,764   73,764  
Share-based Compensation Arrangement by Share-based Payment Award, Additional General Disclosures [Abstract]        
Unrecognized stock-based compensation expense related to unvested stock options $ 1,806   $ 1,806  
Unrecognized compensation expense weighted-average recognition period     2 years 3 months 18 days  
Minimum        
Share-based Compensation Arrangement by Share-based Payment Award, Additional General Disclosures [Abstract]        
Exercise prices of stock options outstanding (in dollars per share) $ 7.15   $ 7.15  
Maximum        
Share-based Compensation Arrangement by Share-based Payment Award, Additional General Disclosures [Abstract]        
Exercise prices of stock options outstanding (in dollars per share) $ 55.29   $ 55.29