Investments - Non-Marketable Equity Securities (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 27, 2021	Jun. 28, 2020	Jun. 27, 2021	Jun. 28, 2020	Dec. 27, 2020
Net Investment Income [Line Items]
Equity securities	$ 20,600		$ 20,600		$ 20,900
Interest income and other expense, net	$ 2,053	$ 2,965	$ 3,743	$ 17,004
Realized gain on partial sale of investment				2,500
Unrealized gain due to mark to market of remaining investment				7,600
Non-marketable equity securities
Net Investment Income [Line Items]
Interest income and other expense, net				$ 10,100