Derivative Financial Instruments - Derivative Instruments and their Balance Sheet Classifications (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Derivatives, Fair Value [Line Items]
Derivative Liabilities	$ 19	$ 96
Derivative Assets	105	26
Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	6	75
Derivative Assets	81	17
Not Designated As Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	13	21
Derivative Assets	24	9
Foreign exchange contracts [Member] | Prepaid and other current assets [Member] | Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	57	16
Foreign exchange contracts [Member] | Prepaid and other current assets [Member] | Not Designated As Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	24	9
Foreign exchange contracts [Member] | Other Assets [Member] | Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Assets	24	1
Foreign exchange contracts [Member] | Accrued liabilities [Member] | Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	5	62
Foreign exchange contracts [Member] | Accrued liabilities [Member] | Not Designated As Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	13	21
Foreign exchange contracts [Member] | Other Liabilities [Member] | Designated as Hedging Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Liabilities	$ 1	$ 13