Location on the Balance Sheet of Derivative Assets and Liabilities (Detail) - Fair Value, Inputs, Level 2 - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Asset Derivatives
Asset Derivatives	$ 792	$ 721
Derivative Asset, Fair Value, Net	756	686
Derivative Liabilities [Abstract]
Liability Derivatives	54	77
Derivative Liability, Fair Value, Amount Offset Against Collateral	18	42
Designated as Hedging Instrument | Foreign Exchange Contracts | Other current assets
Asset Derivatives
Asset Derivatives	337	204
Derivative Asset, Fair Value, Net	337	204
Designated as Hedging Instrument | Foreign Exchange Contracts | Other noncurrent assets
Asset Derivatives
Asset Derivatives	161	229
Derivative Asset, Fair Value, Net	161	229
Designated as Hedging Instrument | Foreign Exchange Contracts | Other non-current liabilities
Derivative Liabilities [Abstract]
Liability Derivatives	0	34
Derivative Liability, Fair Value, Amount Offset Against Collateral	0	34
Designated as Hedging Instrument | Interest Rate Contracts | Other noncurrent assets
Asset Derivatives
Asset Derivatives	218	227
Derivative Asset, Fair Value, Net	185	194
Designated as Hedging Instrument | Interest Rate Contracts | Other non-current liabilities
Derivative Liabilities [Abstract]
Liability Derivatives	34	35
Derivative Liability, Fair Value, Amount Offset Against Collateral	1	2
Not Designated as Hedging Instrument | Foreign Exchange Contracts | Other current assets
Asset Derivatives
Asset Derivatives	19	2
Derivative Asset, Fair Value, Net	19	2
Not Designated as Hedging Instrument | Foreign Exchange Contracts | Other current liabilities
Derivative Liabilities [Abstract]
Liability Derivatives	2	0
Derivative Liability, Fair Value, Amount Offset Against Collateral	2	0
Not Designated as Hedging Instrument | Price Risk Derivative [Member] | Other current assets
Asset Derivatives
Asset Derivatives	1	0
Derivative Asset, Fair Value, Net	0	0
Not Designated as Hedging Instrument | Price Risk Derivative [Member] | Other current liabilities
Derivative Liabilities [Abstract]
Liability Derivatives	10	0
Derivative Liability, Fair Value, Amount Offset Against Collateral	9	0
Not Designated as Hedging Instrument | Interest Rate Contracts | Other noncurrent assets
Asset Derivatives
Asset Derivatives	56	59
Derivative Asset, Fair Value, Net	54	57
Not Designated as Hedging Instrument | Interest Rate Contracts | Other current liabilities
Derivative Liabilities [Abstract]
Liability Derivatives	0	1
Derivative Liability, Fair Value, Amount Offset Against Collateral	0	1
Not Designated as Hedging Instrument | Interest Rate Contracts | Other non-current liabilities
Derivative Liabilities [Abstract]
Liability Derivatives	8	7
Derivative Liability, Fair Value, Amount Offset Against Collateral	$ 6	$ 5