Net Income (Loss) per Share (Details) - shares shares in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Earnings Per Share [Abstract]
Weighted-average shares used in computing basic net income (loss) per share (In shares)	73,157	72,200	72,991	71,821
Add potentially dilutive securities (In shares)	1,376	1,339	1,436	1,364
Weighted Average Number of Shares Outstanding, Diluted	74,533	73,539	74,427	73,185
Anti-dilutive securities (In shares)	76	82	49	96

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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- References

No definition available.

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Additional shares included in the calculation of diluted EPS as a result of the potentially dilutive effect of share based payment arrangements using the treasury stock method.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
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The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

+ References

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Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

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