Location on the Balance Sheet of Derivative Assets and Liabilities (Detail) - Fair Value, Inputs, Level 2 - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Asset Derivatives
Asset Derivatives	$ 433	$ 361
Net Amounts if Right of Offset had been Applied	414	329
Derivative Liabilities [Abstract]
Liability Derivatives	39	67
Net Amounts if Right of Offset had been Applied	20	35
Designated as Hedging Instrument | Foreign exchange contracts | Other current assets
Asset Derivatives
Asset Derivatives	122	90
Net Amounts if Right of Offset had been Applied	117	83
Designated as Hedging Instrument | Foreign exchange contracts | Other non-current assets
Asset Derivatives
Asset Derivatives	277	230
Net Amounts if Right of Offset had been Applied	270	215
Designated as Hedging Instrument | Foreign exchange contracts | Other current liabilities
Derivative Liabilities [Abstract]
Liability Derivatives	5	7
Net Amounts if Right of Offset had been Applied	0	0
Designated as Hedging Instrument | Foreign exchange contracts | Other non-current liabilities
Derivative Liabilities [Abstract]
Liability Derivatives	7	15
Net Amounts if Right of Offset had been Applied	0	0
Designated as Hedging Instrument | Interest rate contracts | Other current assets
Asset Derivatives
Asset Derivatives	0	1
Net Amounts if Right of Offset had been Applied	0	1
Designated as Hedging Instrument | Interest rate contracts | Other non-current assets
Asset Derivatives
Asset Derivatives	16	14
Net Amounts if Right of Offset had been Applied	10	6
Designated as Hedging Instrument | Interest rate contracts | Other non-current liabilities
Derivative Liabilities [Abstract]
Liability Derivatives	26	41
Net Amounts if Right of Offset had been Applied	20	33
Not Designated as Hedging Instrument | Foreign exchange contracts | Other current assets
Asset Derivatives
Asset Derivatives	2	7
Net Amounts if Right of Offset had been Applied	1	5
Not Designated as Hedging Instrument | Foreign exchange contracts | Other non-current assets
Asset Derivatives
Asset Derivatives	0	1
Net Amounts if Right of Offset had been Applied	0	1
Not Designated as Hedging Instrument | Foreign exchange contracts | Other current liabilities
Derivative Liabilities [Abstract]
Liability Derivatives	1	3
Net Amounts if Right of Offset had been Applied	0	1
Not Designated as Hedging Instrument | Foreign exchange contracts | Other non-current liabilities
Derivative Liabilities [Abstract]
Liability Derivatives	0	1
Net Amounts if Right of Offset had been Applied	0	1
Not Designated as Hedging Instrument | Interest rate contracts | Other non-current assets
Asset Derivatives
Asset Derivatives	16	18
Net Amounts if Right of Offset had been Applied	$ 16	$ 18