Marketable Securities - Schedule of Marketable Securities by Category (Details) - USD ($) $ in Thousands	Jun. 26, 2021	Dec. 26, 2020
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 276,526	$ 236,649
Gross Unrealized Holding Gains	176	372
Gross Unrealized Holding Losses	81	19
Fair Value	276,621	237,002
Municipal notes and bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	142,821	124,387
Gross Unrealized Holding Gains	128	257
Gross Unrealized Holding Losses	19	4
Fair Value	142,930	124,640
Asset-backed securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	4,090	11,679
Gross Unrealized Holding Gains	4	29
Gross Unrealized Holding Losses	0	0
Fair Value	4,094	11,708
Certificates of deposits [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	44,003	36,349
Gross Unrealized Holding Gains	19	24
Gross Unrealized Holding Losses	1	0
Fair Value	44,021	36,373
Commercial paper [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	50,961	32,690
Gross Unrealized Holding Gains	19	12
Gross Unrealized Holding Losses	0	3
Fair Value	50,980	32,699
Corporate bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	34,651	31,544
Gross Unrealized Holding Gains	6	50
Gross Unrealized Holding Losses	61	12
Fair Value	$ 34,596	$ 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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