| Financial Instruments and Risk Management (Gross Notional Amount of Outstanding Derivatives) (Details) (Foreign Exchange Forward [Member], USD $) In Thousands, unless otherwise specified | Dec. 31, 2014 | Dec. 31, 2013 | 
|---|---|---|
| Designated as Hedging Instrument [Member] | ||
| Derivatives, Fair Value [Line Items] | ||
| Currency forward contracts | $ 103,000invest_DerivativeNotionalAmount / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_ForeignExchangeForwardMember / us-gaap_HedgingDesignationAxis = us-gaap_DesignatedAsHedgingInstrumentMember | $ 99,000invest_DerivativeNotionalAmount / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_ForeignExchangeForwardMember / us-gaap_HedgingDesignationAxis = us-gaap_DesignatedAsHedgingInstrumentMember | 
| Not Designated as Hedging Instrument [Member] | ||
| Derivatives, Fair Value [Line Items] | ||
| Currency forward contracts | $ 128,000invest_DerivativeNotionalAmount / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_ForeignExchangeForwardMember / us-gaap_HedgingDesignationAxis = us-gaap_NondesignatedMember | $ 109,000invest_DerivativeNotionalAmount / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_ForeignExchangeForwardMember / us-gaap_HedgingDesignationAxis = us-gaap_NondesignatedMember | 
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- Definition Aggregate notional amount specified by the derivative(s). Expressed as an absolute value. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Details 
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