Fair Value (Details) - USD ($) $ in Thousands	Sep. 28, 2019	Dec. 29, 2018
Short-term investments:
Marketable equity securities	$ 3,773	$ 3,887
Securities held in Non-Qualified Deferred Compensation trust, or NQDC	31,196	27,767
Foreign currency exchange contracts		101
Total Assets	386,681	359,596
Liabilities
Foreign currency exchange contracts	2,075
Total Liabilities	2,075
Money market funds [Member]
Assets
Cash equivalents	351,712	327,841
Fair Value Measurements, Level 1 [Member]
Short-term investments:
Marketable equity securities	3,773	3,887
Securities held in Non-Qualified Deferred Compensation trust, or NQDC	31,196	27,767
Foreign currency exchange contracts		0
Total Assets	386,681	359,495
Liabilities
Foreign currency exchange contracts	0
Total Liabilities	0
Fair Value Measurements, Level 1 [Member] \| Money market funds [Member]
Assets
Cash equivalents	351,712	327,841
Fair Value Measurements, Level 2 [Member]
Short-term investments:
Marketable equity securities	0	0
Securities held in Non-Qualified Deferred Compensation trust, or NQDC	0	0
Foreign currency exchange contracts		101
Total Assets	0	101
Liabilities
Foreign currency exchange contracts	2,075
Total Liabilities	2,075
Fair Value Measurements, Level 2 [Member] \| Money market funds [Member]
Assets
Cash equivalents	0	0
Fair Value Measurements, Level 3 [Member]
Short-term investments:
Marketable equity securities	0	0
Securities held in Non-Qualified Deferred Compensation trust, or NQDC	0	0
Foreign currency exchange contracts		0
Total Assets	0	0
Liabilities
Foreign currency exchange contracts	0
Total Liabilities	0
Fair Value Measurements, Level 3 [Member] \| Money market funds [Member]
Assets
Cash equivalents	$ 0	$ 0

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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-Publisher FASB
-Name Accounting Standards Codification
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