Fair Value (Details) - USD ($) $ in Thousands	Mar. 30, 2019	Dec. 29, 2018
Short-term investments:
Marketable equity securities	$ 3,969	$ 3,887
Securities held in Non-Qualified Deferred Compensation trust, or NQDC	28,402	27,767
Foreign currency exchange contracts		101
Total Assets	364,365	359,596
Liabilities [Abstract]
Foreign currency exchange contracts	458
Total Liabilities	458
Money market funds [Member]
Assets
Cash equivalents	331,994	327,841
Fair Value Measurements, Level 1 [Member]
Short-term investments:
Marketable equity securities	3,969	3,887
Securities held in Non-Qualified Deferred Compensation trust, or NQDC	28,402	27,767
Foreign currency exchange contracts		0
Total Assets	364,365	359,495
Liabilities [Abstract]
Foreign currency exchange contracts	0
Total Liabilities	0
Fair Value Measurements, Level 1 [Member] | Money market funds [Member]
Assets
Cash equivalents	331,994	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 [Abstract]
Foreign currency exchange contracts	458
Total Liabilities	458
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 [Abstract]
Foreign currency exchange contracts	0
Total Liabilities	0
Fair Value Measurements, Level 3 [Member] | Money market funds [Member]
Assets
Cash equivalents	$ 0	$ 0