Investments - Non-Marketable Equity Securities (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 26, 2021	Sep. 27, 2020	Sep. 26, 2021	Sep. 27, 2020	Dec. 27, 2020
Net Investment Income [Line Items]
Equity securities	$ 27,400		$ 27,400		$ 20,900
Unrealized gain on equity securities	11,900		15,300	$ 7,600
Interest income and other expense, net	1,598	$ 3,720	$ 5,342	10,650
Realized gain on partial sale of investment	15,200			2,500
Non-marketable equity securities
Net Investment Income [Line Items]
Interest income and other expense, net	$ 27,200			$ 10,100