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Financial Instruments - Fair Value Hedges (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Loans payable and current portion of long-term debt
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Carrying Amount of Hedged Assets (Liabilities)	$ (998)	$ (983)
Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount	2	17
Long-Term Debt
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Carrying Amount of Hedged Assets (Liabilities)	(5,083)	(5,146)
Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount	106	41
Long-Term Debt | Derivatives Not Designated as Hedging Instruments
Derivative Instruments and Hedging Activities Disclosures [Line Items]
Cumulative Amount of Fair Value Hedging Adjustment Included in the Carrying Amount	$ 9	$ 11

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- Definition

Hedged Liability, Fair Value Hedge

+ References

No definition available.

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- Definition

Hedged Liability, Fair Value Hedge, Cumulative Increase (Decrease)

+ 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.

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No definition available.

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- Details

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