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Stock-Based Compensation - Additional Information (Details)
$ / shares in Units, $ in Millions
1 Months Ended 12 Months Ended
Feb. 14, 2019
shares
Feb. 06, 2018
shares
Feb. 17, 2017
shares
Feb. 09, 2016
shares
Jun. 30, 2018
shares
Dec. 31, 2019
USD ($)
performance_period
$ / shares
shares
Dec. 31, 2018
USD ($)
$ / shares
Dec. 31, 2017
USD ($)
$ / shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Stock-based compensation expense           $ 14.9 $ 12.0 $ 7.8
Weighted-average grant date fair value (in dollars per share) | $ / shares           $ 6.39 $ 9.88 $ 4.48
Intrinsic value of stock options exercised           $ 2.0 $ 28.7 $ 15.8
Fair value of stock options vested           6.2 5.9 6.4
Unamortized compensation costs, stock options           $ 16.9    
Restricted stock                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Unamortized compensation costs, weighted average period of recognition           1 year 10 months 24 days    
Awards granted (in shares) | shares           175,795    
Unrecognized compensation cost, other awards           $ 7.9    
Fair value of awards vested           $ 5.5 0.9 1.0
Stock options                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Low end of exercise price range (in dollars per share) | $ / shares           $ 11.61    
High end of exercise price range (in dollars per share) | $ / shares           $ 32.90    
Unamortized compensation costs, weighted average period of recognition           2 years 10 months 24 days    
Stock options | Minimum                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Contractual lives           2 years    
Stock options | Maximum                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Contractual lives           10 years    
Performance shares                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Awards granted (in shares) | shares 278,780 197,727 172,245 189,085   253,609    
Annual increment percentage at which awards are granted           33.33%    
Number of annual award performance periods | performance_period           3    
Service period           3 years    
Vesting period           3 years    
Performance shares | Minimum                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Percentage of award which can potentially be earned           0.00%    
Performance shares | Maximum                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Percentage of award which can potentially be earned           150.00%    
Phantom stock units (PSUs)                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Stock-based compensation expense           $ 4.1 1.1 11.9
Unamortized compensation costs, weighted average period of recognition           1 year 7 months 6 days    
Unrecognized compensation cost, other awards           $ 3.3    
Liability for cash-settled awards           3.3 1.7  
Amounts paid on cash-settled awards           $ 2.5 4.2 12.7
Phantom stock units (PSUs) | Minimum                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Vesting period           3 years    
Phantom stock units (PSUs) | Maximum                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Vesting period           4 years    
Stock appreciation rights (SARs)                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Stock-based compensation expense           $ 10.7 (6.7) 21.9
Unamortized compensation costs, weighted average period of recognition           2 years 7 months 6 days    
Vesting period           4 years    
Unrecognized compensation cost, other awards           $ 9.6    
Liability for cash-settled awards           14.4 6.8  
Amounts paid on cash-settled awards           $ 3.5 $ 10.5 $ 6.2
2018 Long Term Incentive Compensation Plan                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Common stock available for awards, up to (in shares) | shares         12,700,000      
Common stock counted against the maximum shares available for grant for each share awarded under the plan (in shares)         1      
Shares available for future grants (in shares) | shares           8,417,411    
2018 Long Term Incentive Compensation Plan | Restricted stock                
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]                
Common stock counted against the maximum shares available for grant for each share awarded under the plan (in shares)         2.30