Derivative Financial Instruments - Derivative Instruments Gain (Loss) Recognized in Income (Detail) (Foreign forward exchange contracts [Member], Interest expense, net [Member], Derivatives not designated as hedging instruments [Member], USD $)
In Millions, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Foreign forward exchange contracts [Member] | Interest expense, net [Member] | Derivatives not designated as hedging instruments [Member]
   
Derivative Instruments Gain Loss [Line Items]    
Amount of Gain (Loss) Recognized in Income on Derivative $ (28) $ 5