Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 25, 2016	Dec. 27, 2015	Dec. 28, 2014
Fair Value of Financial Instruments [Abstract]
Fair value of available for sale investments, fair value option	$ 23,571	$ 22,539
Gain on available for sale investments, fair value option	$ 1,010	(682)	$ 899
Redemption period	45 days
Reconciliation of Level 3 Assets
Balance at beginning of year	$ (28,360)	(25,340)
(Loss) gain from change in fair value	(410)	(3,020)
Balance at end of year	(28,770)	(28,360)	$ (25,340)
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, assets	3,736	3,476
Derivatives, assets	87,894	107,634
Total assets	91,630	111,110
Derivatives, liabilities	11,309	1,240
Option Agreement	28,770	28,360
Total Liabilities	40,079	29,600
Fair Value, Measurements, Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, assets	3,736	3,476
Derivatives, assets	0	0
Total assets	3,736	3,476
Derivatives, liabilities	0	0
Option Agreement	0	0
Total Liabilities	0	0
Fair Value, Measurements, Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, assets	0	0
Derivatives, assets	87,894	107,634
Total assets	87,894	107,634
Derivatives, liabilities	11,309	1,240
Option Agreement	0	0
Total Liabilities	11,309	1,240
Fair Value, Measurements, Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale securities, assets	0	0
Derivatives, assets	0	0
Total assets	0	0
Derivatives, liabilities	0	0
Option Agreement	28,770	28,360
Total Liabilities	$ 28,770	$ 28,360