Annual report pursuant to Section 13 and 15(d)

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

v3.6.0.2
Share-Based Compensation - Summary of Activity Under Share-Based Compensation Plans (Detail) - USD ($)
$ / shares in Units, shares in Thousands, $ in Millions
 12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Awards Outstanding, Beginning Balance 12,076  
Granted, Awards 1,400  
Exercised, Awards (1,126)  
Forfeited, Awards (352)  
Awards Outstanding, Ending Balance 11,998 12,076
Exercisable Awards, Ending Balance 7,136  
Weighted Average Exercise Price Outstanding, Beginning Balance $ 38.70  
Granted, Weighted Average Exercise Price 62.21  
Exercised, Weighted Average Exercise Price 33.63  
Forfeited, Weighted Average Exercise Price 52.29  
Weighted Average Exercise Price Outstanding, Ending Balance 41.52 $ 38.70
Exercisable, Weighted Average Exercise Price, Ending Balance $ 38.80  
Weighted Average Remaining Contractual Term Outstanding 6 years 6 years 7 months 6 days
Exercisable Weighted Average Remaining Contractual Term 4 years 6 months  
Aggregate Intrinsic Value Outstanding, Beginning balance $ 216.4  
Aggregate Intrinsic Value Outstanding, Ending balance 148.7 $ 216.4
Exercisable, Aggregate Intrinsic Value, Ending Balance $ 106.8  
Incentive Plan and Independent Directors Stock Units [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Outstanding and nonvested at December 31, 2015, Shares 34  
Granted, Shares 27  
Vested, Shares (35)  
Outstanding and nonvested at December 31, 2016, Shares 26 34
Outstanding and nonvested at December 31, 2015, Weighted Average Grant Date Fair Value $ 51.08  
Granted, Weighted Average Grant Date Fair Value 62.30  
Vested, Weighted Average Grant Date Fair Value 51.37  
Outstanding and nonvested at December 31, 2016, Weighted Average Grant Date Fair Value $ 62.35 $ 51.08