Quarterly report pursuant to Section 13 or 15(d)

Share-Based Compensation - Summary of Activity Under Share-Based Compensation Plans (Detail)

v3.21.2
Share-Based Compensation - Summary of Activity Under Share-Based Compensation Plans (Detail) - USD ($)
$ / shares in Units, shares in Thousands, $ in Millions
3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2021
Jun. 30, 2020
Jun. 30, 2021
Jun. 30, 2020
Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Outstanding and nonvested, Beginning Balance, Number of Shares     3,068    
Granted, Number of Shares     1,503    
Vested, Number of Shares     (803)    
Forfeited, Number of Shares     (55)    
Outstanding and nonvested, Ending Balance, Number of Shares 3,713   3,713   3,068
Number of Shares, Expected to vest 3,252   3,252    
Outstanding and nonvested, Beginning Balance, Weighted Average Grant Date Fair Value Per Share     $ 44.01    
Granted, Weighted Average Grant Date Fair Value Per Share     48.37    
Vested, Weighted Average Grant Date Fair Value Per Share     43.49    
Forfeited, Weighted Average Grant Date Fair Value Per Share     44.25    
Outstanding and nonvested, Ending Balance, Weighted Average Grant Date Fair Value Per Share $ 45.89   45.89   $ 44.01
Expected to vest, Ending Balance, Weighted Average Grant Date Fair Value Per Share $ 45.49   $ 45.49    
SARs [Member]          
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]          
Number of Awards Outstanding, Beginning Balance     3,737    
Granted, Number of Awards 0 0 0 0  
Exercised, Number of Awards     (960)    
Forfeited, Number of Awards     (17)    
Number of Awards Outstanding, Ending Balance 2,760   2,760   3,737
Number of Awards Exercisable, Ending Balance 2,760   2,760    
Number of Awards Vested and expected to vest, Ending Balance 2,760   2,760    
Weighted Average Exercise Price Per Award Outstanding, Beginning Balance     $ 27.23    
Exercised, Weighted Average Exercise Price Per Award     27.61    
Forfeited, Weighted Average Exercise Price Per Award     23.48    
Weighted Average Exercise Price Per Award Outstanding, Ending Balance $ 27.12   27.12   $ 27.23
Exercisable, Weighted Average Exercise Price Per Award, Ending Balance 27.12   27.12    
Weighted Average Exercise Price Per Award, Vested and expected to vest, Ending Balance $ 27.12   $ 27.12    
Weighted Average Remaining Contractual Term Outstanding     4 years 3 months 18 days   4 years 7 months 6 days
Exercisable Weighted Average Remaining Contractual Term     4 years 3 months 18 days    
Weighted Average Remaining Contractual Term, Vested and expected to vest     4 years 3 months 18 days    
Aggregate Intrinsic Value Outstanding $ 70.7   $ 70.7   $ 77.8
Exercisable, Aggregate Intrinsic Value 70.7   70.7    
Aggregate Intrinsic Value, Vested and expected to vest $ 70.7   $ 70.7