Marketable Securities - Schedule of Gross Unrealized Losses and Fair Value by Major Security Type (Details) - USD ($) $ in Thousands	Dec. 26, 2020	Dec. 28, 2019
Marketable Securities [Line Items]
Gross Unrealized Losses Less than 12 Consecutive Months	$ (3,863)	$ (2,974)
Fair Value Less than 12 Consecutive Months	357,878	352,211
Gross Unrealized Losses 12 Consecutive Months or Longer	(976)	(4,249)
Fair Value 12 Consecutive Months or Longer	14,173	252,298
Gross Unrealized Losses, Total	(4,839)	(7,223)
Fair Value, Total	372,051	604,509
U.S. Treasury securities [Member]
Marketable Securities [Line Items]
Gross Unrealized Losses 12 Consecutive Months or Longer		(30)
Fair Value 12 Consecutive Months or Longer		13,087
Gross Unrealized Losses, Total		(30)
Fair Value, Total		13,087
Agency securities [Member]
Marketable Securities [Line Items]
Gross Unrealized Losses Less than 12 Consecutive Months		(16)
Fair Value Less than 12 Consecutive Months		20,808
Gross Unrealized Losses 12 Consecutive Months or Longer		(11)
Fair Value 12 Consecutive Months or Longer		20,812
Gross Unrealized Losses, Total		(27)
Fair Value, Total		41,620
Mortgage-backed securities [Member]
Marketable Securities [Line Items]
Gross Unrealized Losses Less than 12 Consecutive Months	(1,849)	(745)
Fair Value Less than 12 Consecutive Months	85,688	79,007
Gross Unrealized Losses 12 Consecutive Months or Longer	(74)	(1,740)
Fair Value 12 Consecutive Months or Longer	2,122	86,392
Gross Unrealized Losses, Total	(1,923)	(2,485)
Fair Value, Total	87,810	165,399
Corporate securities [Member]
Marketable Securities [Line Items]
Gross Unrealized Losses Less than 12 Consecutive Months	(1,065)	(1,585)
Fair Value Less than 12 Consecutive Months	199,187	183,691
Gross Unrealized Losses 12 Consecutive Months or Longer	(572)	(2,161)
Fair Value 12 Consecutive Months or Longer	8,625	100,926
Gross Unrealized Losses, Total	(1,637)	(3,746)
Fair Value, Total	207,812	284,617
Municipal securities [Member]
Marketable Securities [Line Items]
Gross Unrealized Losses Less than 12 Consecutive Months	(223)	(218)
Fair Value Less than 12 Consecutive Months	50,403	34,165
Gross Unrealized Losses 12 Consecutive Months or Longer		(17)
Fair Value 12 Consecutive Months or Longer		9,522
Gross Unrealized Losses, Total	(223)	(235)
Fair Value, Total	50,403	43,687
Other [Member]
Marketable Securities [Line Items]
Gross Unrealized Losses Less than 12 Consecutive Months	(726)	(410)
Fair Value Less than 12 Consecutive Months	22,600	34,540
Gross Unrealized Losses 12 Consecutive Months or Longer	(330)	(290)
Fair Value 12 Consecutive Months or Longer	3,426	21,559
Gross Unrealized Losses, Total	(1,056)	(700)
Fair Value, Total	$ 26,026	$ 56,099

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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