Marketable Securities - Schedule of Marketable Securities by Category (Details) - USD ($) $ in Thousands	Mar. 27, 2021	Dec. 26, 2020
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 266,228	$ 236,649
Gross Unrealized Holding Gains	272	372
Gross Unrealized Holding Losses	50	19
Fair Value	266,450	237,002
Municipal notes and bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	136,345	124,387
Gross Unrealized Holding Gains	202	257
Gross Unrealized Holding Losses	9	4
Fair Value	136,538	124,640
Asset-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	9,169	11,679
Gross Unrealized Holding Gains	11	29
Gross Unrealized Holding Losses	0	0
Fair Value	9,180	11,708
Certificates of deposits [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	36,449	36,349
Gross Unrealized Holding Gains	23	24
Gross Unrealized Holding Losses	0	0
Fair Value	36,472	36,373
Commercial paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	51,769	32,690
Gross Unrealized Holding Gains	21	12
Gross Unrealized Holding Losses	1	3
Fair Value	51,789	32,699
Corporate bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	32,496	31,544
Gross Unrealized Holding Gains	15	50
Gross Unrealized Holding Losses	40	12
Fair Value	$ 32,471	$ 31,582

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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