Acquisitions and Purchase Accounting Acquisitions and Purchase Accounting - Pro Forma Information (Details) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended
Jun. 30, 2018	Jul. 01, 2017
Business Combinations [Abstract]
Business Acquisition, Pro Forma Revenue	$ 1,415,669	$ 1,432,093
Business Acquisition, Pro Forma Net Income (Loss)	$ 142,566	$ 129,622
Business Acquisition, Pro Forma Earnings Per Share, Basic	$ 2.57	$ 2.27
Business Acquisition, Pro Forma Earnings Per Share, Diluted	$ 2.57	$ 2.27

The pro forma basic net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(2)-(3)
-URI http://asc.fasb.org/extlink&oid=79982066&loc=d3e1392-128463

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- Definition

The pro forma diluted net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

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- Definition

The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

+ References

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The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.

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No definition available.

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