v3.10.0.1
Share-based Compensation - Summary of Restricted Share Units (Detail) - Long Term Incentive Plans [Member] - Restricted Share Units [Member] - $ / shares
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Shares, Outstanding at January 1, 2018 6,411,610    
Shares, Granted 3,552,823    
Shares, Vested 3,083,601    
Shares, Forfeited 369,268    
Shares, Outstanding at December 31, 2018 6,511,564 6,411,610  
Weighted average grant date fair value, Outstanding at January 1, 2018 $ 101.13    
Weighted average grant date fair value, Granted 84.77 $ 115.05 $ 98.16
Weighted average grant date fair value, Vested 95.61    
Weighted average grant date fair value, Forfeited 102.84    
Weighted average grant date fair value, Outstanding at December 31, 2018 $ 94.73 $ 101.13