v3.20.4
Share-based Compensation - Summary of Performance Share Units (Detail) - Long Term Incentive Plans - USD ($)
12 Months Ended
Oct. 29, 2019
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Weighted  average grant date  fair value in USD        
Unrecognized compensation cost   $ 0 $ 0  
Performance Share Units        
Weighted  average grant date  fair value in USD        
Weighted average grant date fair value, Granted (in dollars per share) $ 167.64      
Performance Share Units | Financial Performance Conditions        
Shares        
Shares, Outstanding at January 1, 2019 (in shares)   195,098    
Shares, Granted (in shares)   0    
Shares, Vested (in shares)   0    
Shares, Forfeited (in shares)   195,098    
Shares, Outstanding at December 31, 2019 (in shares)   0 195,098  
Weighted  average grant date  fair value in USD        
Weighted average grant date fair value, Outstanding at January 1, 2018 (in dollars per share)   $ 75.60    
Weighted average grant date fair value, Granted (in dollars per share)   0    
Weighted average grant date fair value, Vested (in dollars per share)   0    
Weighted average grant date fair value, Forfeited (in dollars per share)   75.60    
Weighted average grant date fair value, Outstanding at December 31, 2018 (in dollars per share)   $ 0 $ 75.60  
Performance Share Units | Market Performance Conditions        
Shares        
Shares, Outstanding at January 1, 2019 (in shares)   1,844,187    
Shares, Granted (in shares)   335,567    
Shares, Vested (in shares)   0    
Shares, Forfeited (in shares)   48,060    
Shares, Outstanding at December 31, 2019 (in shares)   2,131,694 1,844,187  
Weighted  average grant date  fair value in USD        
Weighted average grant date fair value, Outstanding at January 1, 2018 (in dollars per share)   $ 125.61    
Weighted average grant date fair value, Granted (in dollars per share)   164.92 $ 141.64 $ 121.18
Weighted average grant date fair value, Vested (in dollars per share)   0    
Weighted average grant date fair value, Forfeited (in dollars per share)   125.28    
Weighted average grant date fair value, Outstanding at December 31, 2018 (in dollars per share)   $ 131.81 $ 125.61