Derivative Financial Instruments, Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2018	Oct. 01, 2017	Sep. 30, 2018	Oct. 01, 2017	Dec. 31, 2017
Not Designated as Hedging Instrument [Member] \| Foreign Exchange Forward [Member] \| Other Income (Expense) [Member]
Derivative [Line Items]
Derivative Instruments, Gain (Loss) Recognized in Income, Net	$ 5,030	$ (2,976)	$ 8,781	$ (2,251)
Not Designated as Hedging Instrument [Member] \| Intercompany Loans [Member]
Derivative [Line Items]
Notional amount of derivative	311,331	339,227	311,331	339,227	$ 418,471
Cash Flow Hedging [Member] \| Designated as Hedging Instrument [Member] \| Foreign Exchange Forward [Member]
Derivative [Line Items]
Ineffective portion, amount of gains (losses) reclassified from other comprehensive earnings into earnings	(1,532)	(9)	(4,368)	(6,495)
Notional amount of derivative	$ 992,616	$ 1,740,620	$ 992,616	$ 1,740,620	$ 1,376,877

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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- Definition

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+ References

No definition available.

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- Definition

Amount of gain (loss) from the ineffectiveness of the hedge.

+ 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 (d)(1)
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624171-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 25
-Section 50
-Paragraph 1
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=6886632&loc=d3e76258-113986

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- Definition

Aggregate net gain (loss) on all derivative instruments recognized in earnings during the period, before tax effects.

+ References

Reference 1: 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=84234895&loc=SL5618551-113959

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