Location on the Balance Sheet of Derivative Assets and Liabilities (Detail) - Fair Value, Inputs, Level 2 - USD ($) $ in Millions	Jun. 30, 2016	Dec. 31, 2015
Asset Derivatives
Asset Derivatives	$ 888	$ 768
Derivative Asset, Fair Value, Net	856	738
Derivative Liabilities [Abstract]
Liability Derivatives	85	53
Derivative Liability, Fair Value, Amount Offset Against Collateral	53	23
Designated as Hedging Instrument | Foreign Exchange Contracts | Other current assets
Asset Derivatives
Asset Derivatives	245	408
Derivative Asset, Fair Value, Net	244	408
Designated as Hedging Instrument | Foreign Exchange Contracts | Other noncurrent assets
Asset Derivatives
Asset Derivatives	71	92
Derivative Asset, Fair Value, Net	66	92
Designated as Hedging Instrument | Foreign Exchange Contracts | Other current liabilities
Derivative Liabilities [Abstract]
Liability Derivatives	4	0
Derivative Liability, Fair Value, Amount Offset Against Collateral	2	0
Designated as Hedging Instrument | Foreign Exchange Contracts | Other non-current liabilities
Derivative Liabilities [Abstract]
Liability Derivatives	13	0
Derivative Liability, Fair Value, Amount Offset Against Collateral	9	0
Designated as Hedging Instrument | Interest Rate Contracts | Other noncurrent assets
Asset Derivatives
Asset Derivatives	312	204
Derivative Asset, Fair Value, Net	297	185
Designated as Hedging Instrument | Interest Rate Contracts | Other non-current liabilities
Derivative Liabilities [Abstract]
Liability Derivatives	15	19
Derivative Liability, Fair Value, Amount Offset Against Collateral	0	0
Not Designated as Hedging Instrument | Foreign Exchange Contracts | Other current assets
Asset Derivatives
Asset Derivatives	1	2
Derivative Asset, Fair Value, Net	0	0
Not Designated as Hedging Instrument | Foreign Exchange Contracts | Other current liabilities
Derivative Liabilities [Abstract]
Liability Derivatives	15	12
Derivative Liability, Fair Value, Amount Offset Against Collateral	14	10
Not Designated as Hedging Instrument | Price Risk Derivative [Member] | Other current assets
Asset Derivatives
Asset Derivatives	181	5
Derivative Asset, Fair Value, Net	181	0
Not Designated as Hedging Instrument | Price Risk Derivative [Member] | Other current liabilities
Derivative Liabilities [Abstract]
Liability Derivatives	0	9
Derivative Liability, Fair Value, Amount Offset Against Collateral	0	4
Not Designated as Hedging Instrument | Interest Rate Contracts | Other noncurrent assets
Asset Derivatives
Asset Derivatives	78	57
Derivative Asset, Fair Value, Net	68	53
Not Designated as Hedging Instrument | Interest Rate Contracts | Other non-current liabilities
Derivative Liabilities [Abstract]
Liability Derivatives	38	13
Derivative Liability, Fair Value, Amount Offset Against Collateral	$ 28	$ 9