Balance Sheet Components (Schedule of Available-for-Sale Short-Term Investments) (Details) - USD ($) $ in Thousands	Mar. 29, 2020	Dec. 31, 2019
Debt Securities, Available-for-sale [Line Items]
Cost	$ 1,456	$ 1,475
Unrealized Gains	0	0
Unrealized Losses	0	0
Allowance for Credit Losses	0
Estimated Fair Value	1,456	1,475
Certificates of deposits
Debt Securities, Available-for-sale [Line Items]
Cost	130	149
Unrealized Gains	0	0
Unrealized Losses	0	0
Allowance for Credit Losses	0
Estimated Fair Value	130	149
Convertible debt
Debt Securities, Available-for-sale [Line Items]
Cost	1,326	1,326
Unrealized Gains	0	0
Unrealized Losses	0	0
Allowance for Credit Losses	0
Estimated Fair Value	$ 1,326	$ 1,326

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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