Other General Expenses (Income) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 29, 2020	Mar. 31, 2019
General and Administrative Expenses
General and administrative expenses	$ 47,651	$ 51,135
General and administrative expenses
General and Administrative Expenses
Other general expenses (income)	4,674	(100)
Increase in other general expenses (income) from marketing fund investment	4,800
Marketing fund investment amount	5,000
Special charges		10,619
Advisory and legal costs		5,000
Increase in administrative expenses from higher management incentive costs and higher professional fees	2,400
Administrative expenses	42,977	40,616
General and administrative expenses	$ 47,651	51,135
General and administrative expenses | Series B Preferred Stock
General and Administrative Expenses
Starboard option valuation		$ 5,600