Fair Value of Financial Instruments, Significant Unobservable Inputs Roll Forward (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 02, 2017	Jun. 26, 2016	Jul. 02, 2017	Jun. 26, 2016	Dec. 25, 2016
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of year			$ (28,770)	$ (28,360)
Gain from change in fair value			270	800
Balance at end of period	$ (28,500)	$ (27,560)	(28,500)	(27,560)
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Other (income) expense, net	6,010	3,748	17,396	(1,124)
Fair Value, Measurements, Recurring [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Alternative Investments, Fair Value Disclosure	23,967	23,056	23,967	23,056	$ 23,571
Other (income) expense, net	$ 384	$ 399	$ 1,015	$ 482