Financial Instruments - Fair Value of Derivative Instruments (Details) - USD ($) $ in Millions	Jun. 30, 2018	Dec. 31, 2017
Derivatives, Fair Value [Line Items]
Asset Derivatives	$ 740	$ 179
Liability Derivatives	583	825
Derivatives Designated as Hedging Instruments
Derivatives, Fair Value [Line Items]
Asset Derivatives	405	15
Liability Derivatives	403	509
Derivatives Designated as Hedging Instruments \| Interest rate contracts
Derivatives, Fair Value [Line Items]
Asset Derivatives	20	15
Liability Derivatives	403	509
Derivatives Designated as Hedging Instruments \| Net investment hedge contracts
Derivatives, Fair Value [Line Items]
Asset Derivatives	385	0
Liability Derivatives	0	0
Derivatives Not Designated as Hedging Instruments
Derivatives, Fair Value [Line Items]
Asset Derivatives	335	164
Liability Derivatives	180	316
Derivatives Not Designated as Hedging Instruments \| Currency exchange contracts
Derivatives, Fair Value [Line Items]
Asset Derivatives	111	65
Liability Derivatives	53	76
Derivatives Not Designated as Hedging Instruments \| Commodity contracts
Derivatives, Fair Value [Line Items]
Asset Derivatives	217	84
Liability Derivatives	122	229
Derivatives Not Designated as Hedging Instruments \| Interest rate contracts
Derivatives, Fair Value [Line Items]
Asset Derivatives	7	15
Liability Derivatives	$ 5	$ 11

Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and elected not to be offset.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

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- Definition

Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and elected not to be offset.

+ References

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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