Aggregate notional amount specified by the derivative(s). Expressed as an absolute value.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Article 12
-Section 13
-Sentence Column B

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Fair value as of the balance sheet date of all foreign currency derivative assets designated as cash flow hedging instruments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4B
-Subparagraph (c)(1)
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Fair value as of the balance sheet date of all foreign currency derivative liabilities designated as cash flow hedging instruments.

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Fair value as of the balance sheet date of all foreign currency derivative assets not designated as hedging instruments.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
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Fair value as of the balance sheet date of all foreign currency derivative liabilities not designated as hedging instruments.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4B
-Subparagraph (c)(2)
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Amount of gain (loss) recognized in earnings in the period from the increase (decrease) in fair value of foreign currency derivatives not designated as hedging instruments.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
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Financing Arrangements and Derivative Financial Instruments - Fair Values for Foreign Currency Contracts (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Not Designated as Hedging Instrument
Derivative Instruments and Hedging Activities Disclosures
Foreign currency derivatives, notional amount	$ 1,511		$ 1,409
Foreign currency derivatives, net transaction gains (losses)	2	$ (4)
Designated as Hedging Instrument
Derivative Instruments and Hedging Activities Disclosures
Foreign currency derivatives, notional amount	259		250
Accounts receivable
Derivative Instruments and Hedging Activities Disclosures
Fair value - asset, not designated as hedging instruments	19		3
Fair value - asset, designated as hedging instruments	1		1
Other current liabilities
Derivative Instruments and Hedging Activities Disclosures
Fair value - liability, not designated as hedging instruments	(7)		(9)
Fair value - liability, designated as hedging instruments	(10)		(8)
Other long term liabilities
Derivative Instruments and Hedging Activities Disclosures
Fair value - liability, designated as hedging instruments	$ (2)		$ (2)