Fair Value (Details) - USD ($) $ in Thousands	Sep. 29, 2018	Dec. 30, 2017
Short-term investments:
Marketable equity securities	$ 5,446	$ 4,455
Trading securities held in Non-Qualified Deferred Compensation plan, or NQDC	30,386	31,473
Foreign currency exchange contracts	2,394	2,937
Total Assets	380,745	542,799
Money market funds [Member]
Assets
Cash equivalents	342,519	503,934
Fair Value Measurements, Level 1 [Member]
Short-term investments:
Marketable equity securities	5,446	4,455
Trading securities held in Non-Qualified Deferred Compensation plan, or NQDC	30,386	31,473
Foreign currency exchange contracts	0	0
Total Assets	378,351	539,862
Fair Value Measurements, Level 1 [Member] | Money market funds [Member]
Assets
Cash equivalents	342,519	503,934
Fair Value Measurements, Level 2 [Member]
Short-term investments:
Marketable equity securities	0	0
Trading securities held in Non-Qualified Deferred Compensation plan, or NQDC	0	0
Foreign currency exchange contracts	2,394	2,937
Total Assets	2,394	2,937
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
Trading securities held in Non-Qualified Deferred Compensation plan, or NQDC	0	0
Foreign currency exchange contracts	0	0
Total Assets	0	0
Fair Value Measurements, Level 3 [Member] | Money market funds [Member]
Assets
Cash equivalents	$ 0	$ 0