Fair Value Information and Derivative Financial Instruments (Details 1) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional amount of derivatives	$ 40,050invest_DerivativeNotionalAmount	$ 41,189invest_DerivativeNotionalAmount
Fair value of derivatives	3,456	(106)
Prepaid expenses [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional amount of derivative assets	40,050	10,614
Fair value of derivative assets	3,456	303
Prepaid expenses [Member] \| Forward Contracts [Member] \| Price Risk Derivative [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional amount of derivative assets	0	5,663
Fair value of derivative assets	0	11
Other liabilities and accrued items [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional amount of derivative liabilities	0	29,623
Fair value of derivative liabilities	0	(394)
Other liabilities and accrued items [Member] \| Swap [Member] \| Price Risk Derivative [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional amount of derivative liabilities	0	4,511
Fair value of derivative liabilities	0	(30)
Japan, Yen \| Prepaid expenses [Member] \| Forward Contracts [Member] \| Foreign Exchange Forward [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional amount of derivative assets	6,835	4,951
Fair value of derivative assets	773	292
Euro Member Countries, Euro \| Prepaid expenses [Member] \| Forward Contracts [Member] \| Foreign Exchange Forward [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional amount of derivative assets	33,215	0
Fair value of derivative assets	2,683	0
Euro Member Countries, Euro \| Other liabilities and accrued items [Member] \| Forward Contracts [Member] \| Foreign Exchange Forward [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional amount of derivative liabilities	0	25,112
Fair value of derivative liabilities	0	(364)
Euro Member Countries, Euro \| Other long-term liabilities [Member] \| Forward Contracts [Member] \| Foreign Exchange Forward [Member]
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Notional amount of derivative liabilities	0	952
Fair value of derivative liabilities	$ 0	$ (15)

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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Nominal or face amount used to calculate payments on the derivative asset.

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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 1B

-URI http://asc.fasb.org/extlink&oid=35706170&loc=SL5580258-113959

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