Location on the Balance Sheet of Derivative Assets and Liabilities (Detail) (Fair Value, Inputs, Level 2, USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Asset Derivatives
Asset Derivatives	$ 438	$ 566
Derivative Asset, Fair Value, Net	360	540
Derivative Liabilities [Abstract]
Liability Derivatives	198	159
Derivative Asset, Fair Value, Net	120	133
Designated as Hedging Instrument | Foreign Exchange Contracts | Other current assets
Asset Derivatives
Asset Derivatives	64	27
Derivative Asset, Fair Value, Net	64	27
Designated as Hedging Instrument | Foreign Exchange Contracts | Other noncurrent assets
Asset Derivatives
Asset Derivatives	34	14
Derivative Asset, Fair Value, Net	34	12
Designated as Hedging Instrument | Foreign Exchange Contracts | Other non-current liabilities
Derivative Liabilities [Abstract]
Liability Derivatives	113	103
Derivative Asset, Fair Value, Net	113	101
Designated as Hedging Instrument | Interest Rate Contracts | Other current assets
Asset Derivatives
Asset Derivatives	21	1
Derivative Asset, Fair Value, Net	21	1
Designated as Hedging Instrument | Interest Rate Contracts | Other noncurrent assets
Asset Derivatives
Asset Derivatives	236	420
Derivative Asset, Fair Value, Net	162	406
Designated as Hedging Instrument | Interest Rate Contracts | Other non-current liabilities
Derivative Liabilities [Abstract]
Liability Derivatives	79	14
Derivative Asset, Fair Value, Net	5	0
Not Designated as Hedging Instrument | Foreign Exchange Contracts | Other current assets
Asset Derivatives
Asset Derivatives	22	3
Derivative Asset, Fair Value, Net	21	3
Not Designated as Hedging Instrument | Foreign Exchange Contracts | Other current liabilities
Derivative Liabilities [Abstract]
Liability Derivatives	(1)	(1)
Derivative Asset, Fair Value, Net	0	(1)
Not Designated as Hedging Instrument | Interest Rate Contracts | Other noncurrent assets
Asset Derivatives
Asset Derivatives	61	101
Derivative Asset, Fair Value, Net	58	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