Marketable Securities - Schedule of Marketable Securities by Category (Details) - USD ($) $ in Thousands	Sep. 26, 2020	Dec. 31, 2019
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 238,330	$ 189,309
Gross Unrealized Holding Gains	501	260
Gross Unrealized Holding Losses	34	6
Fair Value	238,797	189,563
Municipal notes and bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	111,137	80,926
Gross Unrealized Holding Gains	270	188
Gross Unrealized Holding Losses	6	6
Fair Value	111,401	81,108
Asset-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	15,109	10,767
Gross Unrealized Holding Gains	51	12
Fair Value	15,160	10,779
Certificates of deposits [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	39,649	30,500
Gross Unrealized Holding Gains	36	7
Fair Value	39,685	30,507
Commercial paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	27,472	30,707
Gross Unrealized Holding Gains	18	1
Gross Unrealized Holding Losses	1
Fair Value	27,489	30,708
Corporate bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	44,963	36,409
Gross Unrealized Holding Gains	126	52
Gross Unrealized Holding Losses	27
Fair Value	$ 45,062	$ 36,461

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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