Objectives And Strategies For Using Derivatives (Narratives) (Details) - USD ($)	3 Months Ended
Mar. 31, 2017	Mar. 31, 2016
Derivative Instruments, Gain (Loss)
Fair value hedge ineffectiveness assertion	Fair value hedges resulted in no significant ineffectiveness in the three months ended March 31, 2017 and 2016
Gain (loss) recognized in earnings as a result of hedge not qualifying as a fair value hedge	$ 0	$ 0
Cash flow hedge ineffectiveness assertion	Cash flow hedges resulted in no significant ineffectiveness for the three months ended March 31, 2017 and 2016
Gain (loss) reclassified into earnings as a result of discontinuance of cash flow hedges	$ 0	0
Not Designated as Hedging Instrument
Derivative Instruments, Gain (Loss)
Aggregate notional values of outstanding derivatives	1,800,000,000
Gain (loss) on undesignated foreign exchange hedging instruments	(3,000,000)	$ 28,000,000
Net Investment Hedging
Derivative Instruments, Gain (Loss)
Aggregate notional values of outstanding derivatives	$ 112,000,000
Cash Flow Hedging
Derivative Instruments, Gain (Loss)
Derivative, Maturity Date	Apr. 26, 2019
Cash Flow Hedging \| Foreign currency exchange contracts
Derivative Instruments, Gain (Loss)
Aggregate notional values of outstanding derivatives	$ 740,000,000
Cash Flow Hedging \| Interest Rate Contract
Derivative Instruments, Gain (Loss)
Aggregate notional values of outstanding derivatives	$ 550,000,000

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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A disclosure of an assertion that the amount of cash flow hedge ineffectiveness is immaterial.

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Date the derivative contract matures, in CCYY-MM-DD format.

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Entity discloses that the amount of fair value hedge ineffectiveness is immaterial.

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Amount of gain recognized in earnings when a hedged firm commitment no longer qualifies as a fair value hedge.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 25
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6886632&loc=d3e76258-113986

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The amount of net gain (loss) reclassified into earnings in the period when cash flow hedge is discontinued because it is probable that the original forecasted transactions will not occur by the end of the original period or an additional two month time period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=35736893&loc=d3e80748-113994

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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5624171-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=64837297&loc=SL5618551-113959

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