Derivative Financial Instruments Schedule of Derivatives (Details)	3 Months Ended			6 Months Ended
	Jun. 26, 2016 USD ($)	Mar. 27, 2016 contract	Jun. 28, 2015 USD ($)	Jun. 26, 2016 USD ($)	Jun. 28, 2015 USD ($)
Derivative [Line Items]
Net effect of swaps	$ 5,410,000		$ (1,407,000)	$ 7,252,000	$ (1,523,000)
Interest Rate Swap [Member]
Derivative [Line Items]
Amortization of deferred hedge gains	2,400,000		1,700,000	3,900,000	3,400,000
Cash Flow Hedging [Member] | Forward-Starting Interest Rate Swap [Member]
Derivative [Line Items]
Accumulated other comprehensive income (loss) related to cash flow hedges	23,600,000			23,600,000
Interest rate cash flow hedge gain (loss) to be reclassified	9,500,000			9,500,000
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	$ (3,046,000)		$ 3,093,000	$ (3,311,000)	$ 4,896,000