Location on the Balance Sheet of Derivative Assets and Liabilities (Detail) (Fair Value, Inputs, Level 2, USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Asset Derivatives
Asset Derivatives	$ 382	$ 566
Derivative Asset, Fair Value, Net	303	540
Derivative Liabilities [Abstract]
Liability Derivatives	106	159
Derivative Asset, Fair Value, Net	27	133
Designated as Hedging Instrument | Foreign Exchange Contracts | Other current assets
Asset Derivatives
Asset Derivatives	18	27
Derivative Asset, Fair Value, Net	18	27
Designated as Hedging Instrument | Foreign Exchange Contracts | Other noncurrent assets
Asset Derivatives
Asset Derivatives	32	14
Derivative Asset, Fair Value, Net	32	12
Designated as Hedging Instrument | Foreign Exchange Contracts | Other non-current liabilities
Derivative Liabilities [Abstract]
Liability Derivatives	22	103
Derivative Asset, Fair Value, Net	22	101
Designated as Hedging Instrument | Interest Rate Contracts | Other current assets
Asset Derivatives
Asset Derivatives	15	1
Derivative Asset, Fair Value, Net	15	1
Designated as Hedging Instrument | Interest Rate Contracts | Other noncurrent assets
Asset Derivatives
Asset Derivatives	243	420
Derivative Asset, Fair Value, Net	171	406
Designated as Hedging Instrument | Interest Rate Contracts | Other non-current liabilities
Derivative Liabilities [Abstract]
Liability Derivatives	75	14
Derivative Asset, Fair Value, Net	3	0
Not Designated as Hedging Instrument | Foreign Exchange Contracts | Other current assets
Asset Derivatives
Asset Derivatives	12	3
Derivative Asset, Fair Value, Net	8	3
Not Designated as Hedging Instrument | Foreign Exchange Contracts | Other current liabilities
Derivative Liabilities [Abstract]
Liability Derivatives	(4)	(1)
Derivative Asset, Fair Value, Net	0	(1)
Not Designated as Hedging Instrument | Interest Rate Contracts | Other noncurrent assets
Asset Derivatives
Asset Derivatives	62	101
Derivative Asset, Fair Value, Net	59	91
Not Designated as Hedging Instrument | Interest Rate Contracts | Other current liabilities
Derivative Liabilities [Abstract]
Liability Derivatives	1	0
Derivative Asset, Fair Value, Net	1	0
Not Designated as Hedging Instrument | Interest Rate Contracts | Other non-current liabilities
Derivative Liabilities [Abstract]
Liability Derivatives	4	41
Derivative Asset, Fair Value, Net	$ 1	$ 31