Derivative Financial Instruments (Narrative) (Details) $ in Millions	12 Months Ended
Dec. 31, 2017 USD ($) derivative_instrument derivative_instruments
Foreign Currency Forward Contracts [Member] \| Maximum [Member]
Derivative [Line Items]
Derivative, term of contract (in months)	11 months
Foreign Currency Forward Contracts [Member] \| Cash Flow Hedges [Member]
Derivative [Line Items]
Approximate number of derivatives per quarter (in derivatives) \| derivative_instrument	10
Derivative, Average size of contracts	$ 8.0
Estimated term of reclassification from OCI to earnings (in months)	12 months
Hedge period of forecasted hedge transaction (in days)	60 days
Derivatives Designated As Hedging Instruments [Member] \| Cash Flow Hedges [Member] \| Maximum [Member]
Derivative [Line Items]
Derivative, term of contract (in months)	11 months
Derivatives Not Designated As Hedging Instruments [Member] \| Foreign Currency Forward Contracts [Member]
Derivative [Line Items]
Derivative, Average size of contracts	$ 2.0
Derivatives Not Designated As Hedging Instruments [Member] \| Foreign Currency Forward Contracts [Member] \| Minimum [Member]
Derivative [Line Items]
Derivative, term of contract (in months)	1 month
Derivatives Not Designated As Hedging Instruments [Member] \| Foreign Currency Forward Contracts [Member] \| Maximum [Member]
Derivative [Line Items]
Derivative, term of contract (in months)	3 months
Approximate number of derivatives per quarter (in derivatives) \| derivative_instruments	10

Average size of derivative contract

No definition available.

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- Definition

Maximum number of days after hedge period allowed before de-designation

+ References

No definition available.

+ Details

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- Definition

Estimated period for the anticipated transfer of gain (loss), net, from accumulated other comprehensive income into earnings, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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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.

+ Details

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- Definition

The number of derivative instruments of a particular group held by the entity.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5580258-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5579245-113959

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- Definition

Period the derivative contract is outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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