Fair Value (Details) - USD ($) $ in Thousands	Mar. 28, 2020	Dec. 28, 2019
Short-term investments:
Marketable equity securities	$ 3,870	$ 4,600
Securities held in Non-Qualified Deferred Compensation trust, or NQDC	29,059	34,096
Foreign currency exchange contracts		3,557
Total Assets	548,610	488,195
Liabilities
Foreign currency exchange contracts	2,286
Total Liabilities	2,286
Money market funds [Member]
Assets
Cash equivalents	515,681	445,942
Fair Value Measurements, Level 1 [Member]
Short-term investments:
Marketable equity securities	3,870	4,600
Securities held in Non-Qualified Deferred Compensation trust, or NQDC	29,059	34,096
Foreign currency exchange contracts		0
Total Assets	548,610	484,638
Liabilities
Foreign currency exchange contracts	0
Total Liabilities	0
Fair Value Measurements, Level 1 [Member] | Money market funds [Member]
Assets
Cash equivalents	515,681	445,942
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		3,557
Total Assets	0	3,557
Liabilities
Foreign currency exchange contracts	2,286
Total Liabilities	2,286
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