Derivative Financial Instruments Schedule of Derivatives (Details)	3 Months Ended			9 Months Ended
	Sep. 25, 2016 USD ($)	Mar. 27, 2016 contract	Sep. 27, 2015 USD ($)	Sep. 25, 2016 USD ($)	Sep. 27, 2015 USD ($)
Derivative [Line Items]
Net effect of swaps	$ 1,650,000		$ (1,439,000)	$ 8,902,000	$ (2,962,000)
Interest Rate Swap [Member]
Derivative [Line Items]
Amortization of deferred hedge gains	2,400,000		1,700,000	6,300,000	5,100,000
Cash Flow Hedging [Member] | Forward-Starting Interest Rate Swap [Member]
Derivative [Line Items]
Interest rate cash flow hedge gain (loss) to be reclassified	9,500,000			9,500,000
Accumulated other comprehensive income (loss) related to cash flow hedges	21,300,000			21,300,000
Cash Flow Hedging [Member] | Forward-Starting Interest Rate Swap [Member] | 2013 forwards [Member]
Derivative [Line Items]
Number of derivative instruments | contract		4
Derivative, extension of maturity (in years)		2 years
Average rate		2.64%
Designated As Hedging [Member]
Derivative [Line Items]
Interest rate cash flow hedge gain (loss) to be reclassified	0			0
Net Effect of Swaps [Member] | Designated As Hedging [Member] | Cash Flow Hedging [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Amount and Location of Gain (Loss) Recognized in Income on Derivatives	$ 715,000		$ 3,125,000	$ (2,596,000)	$ 8,021,000