Balance Sheet Components (Schedule of Changes in Carrying Value of Long-term Investments) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Mar. 29, 2020	Jun. 28, 2020	Jun. 30, 2019
Balance Sheet Related Disclosures [Abstract]
Carrying value as of the beginning of the period	$ 8,147	$ 8,147	$ 2,886
Additions from purchase of investments		5,815	5,200
Impairment	$ (4,500)	(4,530)	0
Carrying value as of the end of the period		$ 9,432	$ 8,086