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Stock-Based Compensation - Additional Information (Detail) - USD ($)
$ / shares in Units, $ in Millions
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Reduction in number of shares available for grant, for every one restricted share or restricted stock unit awarded 2    
Shares available to be awarded under the plan 5,440,508    
Restricted stock units      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Weighted average grant date fair value of restricted stock units granted $ 28.51 $ 29.94 $ 25.77
Fair value of restricted stock units released $ 9.7 $ 12.8 $ 9.3
Unrecognized compensation expense related to restricted stock units $ 25.3    
Cost expected to be recognized over a period 3 years    
Selling, General and Administrative Expense      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Stock compensation expense $ 14.9 $ 14.6 $ 13.0
Maximum [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Maximum aggregate number of shares of common stock that may be issued in connection with stock options, stock appreciation rights, restricted stock, restricted stock units and performance award 19,200,000    
Maximum [Member] | Restricted stock units      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Maximum vesting period for restricted stock units outstanding 6 years