Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation - Additional Information (Details)

v3.20.1
Stock-Based Compensation - Additional Information (Details) - USD ($)
$ / shares in Units, $ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2018
Jun. 30, 2019
Jun. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Granted (in dollars per share)   $ 0  
Options, outstanding, intrinsic value   $ 68.0  
Options, exercisable, intrinsic value   65.5  
Options, exercised, intrinsic value   $ 2.6  
Term for outstanding stock   5 years 4 months 24 days  
Term for exercisable stock   5 years 2 months 12 days  
Performance stock units      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Target Shares Granted (in shares)   199,413  
Incentive Award Plan      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Tax benefit from compensation expense   $ 4.7 $ 2.2
Compensation not yet recognized, stock options   $ 21.3  
Compensation cost not yet recognized, period for recognition   2 years 1 month 6 days  
Incentive Award Plan | Stock options      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Stock-based compensation   $ 0.3 0.3
Incentive Award Plan | Restricted stock      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Stock-based compensation   $ 2.4 $ 1.2
Target Shares Granted (in shares)   373,479  
Restricted stock units, conversion of stock, conversion rights (in shares)   1  
Compensation not yet recognized, stock options   $ 10.8  
Compensation cost not yet recognized, period for recognition   2 years 2 months 12 days  
Incentive Award Plan | Performance stock units      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Stock-based compensation $ 0.7 $ 2.0  
Minimum | Performance stock units      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
PSU's that may be earned   0.00%  
Maximum | Performance stock units      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
PSU's that may be earned   200.00%