Earnings Per Share - Reconciliation of the Earnings (Losses) and Number of Shares Used in Calculations of Basic and Diluted Earnings Per Share (Detail) (USD $)
In Millions, except Per Share data, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Computation of Basic Earnings Per Share    
Net income $ 207 $ 172
Weighted average shares outstanding 277.7 296.1
Basic earnings per share (in USD per share) $ 0.75 $ 0.58
Computation of Diluted Earnings Per Share    
Net income $ 207 $ 172
Weighted average shares outstanding 277.7 296.1
Effect of dilutive securities    
Shares for diluted earnings per share 283.5 303.3
Diluted earnings per share (in USD per share) $ 0.73 $ 0.57
Employee stock option and appreciation right plans    
Effect of dilutive securities    
Effect of dilutive securities 2.4 3.4
Deferred stock incentive plans    
Effect of dilutive securities    
Effect of dilutive securities 0.7 0.8
Restricted stock units    
Effect of dilutive securities    
Effect of dilutive securities 2.7 3.0