Annual report pursuant to Section 13 and 15(d)

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

v3.10.0.1
Share-Based Compensation - Summary of Activities Under Share-Based Compensation Plans (Detail) - USD ($)
$ / shares in Units, shares in Thousands, $ in Millions
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Outstanding and nonvested as of December 31, 2017, Number of Shares 326  
Granted, Number of Shares 1,386  
Vested, Number of Shares (44)  
Forfeited, Number of Shares (57)  
Outstanding and nonvested as of December 31, 2018, Shares 1,611 326
Number of Shares, Expected to vest as of December 31, 2018 1,111  
Outstanding and nonvested as of December 31, 2017, Weighted Average Grant Date Fair Value Per Share $ 34.34  
Granted, Weighted Average Grant Date Fair Value Per Share 43.75  
Vested, Weighted Average Grant Date Fair Value Per Share 35.62  
Forfeited, Weighted Average Grant Date Fair Value Per Share 43.15  
Outstanding and nonvested as of December 31, 2018, Weighted Average Grant Date Fair Value Per Share 42.09 $ 34.34
Expected to vest as of December 31, 2018, Weighted Average Grant Date Fair Value Per Share $ 43.47  
SARs [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Number of Awards Outstanding, Beginning Balance 19,193  
Exercised, Number of Awards (10,369)  
Forfeited, Number of Awards (354)  
Number of Awards Outstanding, Ending Balance 8,470 19,193
Number of Awards Exercisable, Ending Balance 5,220  
Number of Awards Vested and expected to vest, Ending Balance 8,279  
Weighted Average Exercise Price Per Award Outstanding, Beginning Balance $ 23.36  
Exercised, Weighted Average Exercise Price Per Award 20.34  
Forfeited, Weighted Average Exercise Price Per Award 28.91  
Weighted Average Exercise Price Per Award Outstanding, Ending Balance 26.82 $ 23.36
Exercisable, Weighted Average Exercise Price Per Award, Ending Balance 25.03  
Weighted Average Exercise Price Per Award, Vested and expected to vest, Ending Balance $ 26.76  
Weighted Average Remaining Contractual Term Outstanding 6 years 1 month 6 days 6 years 2 months 12 days
Exercisable Weighted Average Remaining Contractual Term 5 years  
Weighted Average Remaining Contractual Term, Vested and expected to vest 6 years  
Aggregate Intrinsic Value Outstanding $ 272.1 $ 212.0
Exercisable, Aggregate Intrinsic Value 177.1  
Aggregate Intrinsic Value, Vested and expected to vest $ 266.5