XML 54 R84.htm IDEA: XBRL DOCUMENT v3.19.3.a.u2
Stock-Based Compensation - Additional Information (Detail) - USD ($)
$ / shares in Units, $ in Millions
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
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 4,378,990    
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 $ 28.51 $ 29.94
Fair value of restricted stock units released $ 37.2 $ 9.7 $ 12.8
Unrecognized compensation expense related to restricted stock units $ 38.8    
Cost expected to be recognized over a period 2 years 9 months 18 days    
Selling, General and Administrative Expense      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Stock compensation expense $ 17.1 $ 14.9 $ 14.6
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 5 years