Marketable Securities - Summary of Estimated Fair Value and Gross Unrealized Holding Losses of Marketable Securities in Unrealized Loss Position (Details) - USD ($) $ in Thousands	Mar. 27, 2021	Dec. 26, 2020
Schedule of Available-for-sale Securities [Line Items]
In Unrealized Loss Position For Less Than 12 Months, Fair Value	$ 42,040	$ 32,450
In Unrealized Loss Position For Less Than 12 Months, Gross Unrealized Losses	50	19
In Unrealized Loss Position For Greater Than 12 Months, Fair Value	0	0
In Unrealized Loss Position For Greater Than 12 Months, Gross Unrealized Losses	0	0
Municipal notes and bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
In Unrealized Loss Position For Less Than 12 Months, Fair Value	15,472	8,641
In Unrealized Loss Position For Less Than 12 Months, Gross Unrealized Losses	9	4
In Unrealized Loss Position For Greater Than 12 Months, Fair Value	0	0
In Unrealized Loss Position For Greater Than 12 Months, Gross Unrealized Losses	0	0
Commercial paper [Member]
Schedule of Available-for-sale Securities [Line Items]
In Unrealized Loss Position For Less Than 12 Months, Fair Value	5,991	8,862
In Unrealized Loss Position For Less Than 12 Months, Gross Unrealized Losses	1	3
In Unrealized Loss Position For Greater Than 12 Months, Fair Value	0	0
In Unrealized Loss Position For Greater Than 12 Months, Gross Unrealized Losses	0	0
Corporate bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
In Unrealized Loss Position For Less Than 12 Months, Fair Value	20,577	14,947
In Unrealized Loss Position For Less Than 12 Months, Gross Unrealized Losses	40	12
In Unrealized Loss Position For Greater Than 12 Months, Fair Value	0	0
In Unrealized Loss Position For Greater Than 12 Months, Gross Unrealized Losses	$ 0	$ 0