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Share-Based Compensation Plans - Nonvested Restricted Stock Unit Awards (Detail) - Restricted Stock Unit Awards - $ / shares
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
NUMBER    
Beginning Balance (in shares) 2,624,210  
Granted (in shares) 772,848  
Vested (in shares) (1,244,630)  
Forfeited (in shares) (26,547)  
Ending Balance (in shares) 2,125,881 2,624,210
WEIGHTED AVERAGE GRANT- DATE FAIR VALUE PER UNIT    
Nonvested at beginning of year (in dollars per share) $ 87.26  
Granted (in dollars per share) 99.58  
Vested (in dollars per share) 80.46  
Forfeited (in dollars per share) 95.41  
Nonvested at end of year (in dollars per share) $ 95.61 $ 87.26
WEIGHTED AVERAGE REMAINING VESTING TERM (YEARS)    
WEIGHTED AVERAGE REMAINING VESTING TERM (YEARS) 2 years 1 month 6 days 1 year 8 months 12 days