Balance Sheet Components (Schedule of Changes in Carrying Value of Long-term Investments) (Details) - USD ($) $ in Thousands		3 Months Ended	9 Months Ended
		Sep. 27, 2020	Sep. 27, 2020	Sep. 29, 2019
Balance Sheet Related Disclosures [Abstract]
Carrying value as of the beginning of the period			$ 8,147	$ 2,886
Additions from purchase of investments			5,850	5,484
Impairment and downward adjustments for price changes		$ (800)	(5,372)	(223)
Carrying value as of the end of the period	[1]	$ 8,625	$ 8,625	$ 8,147

[1] The balance as of September 27, 2020 did not include the investment in limited partnership fund of $0.4 million.