Derivative Financial Instruments Income Statement Location (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 24, 2017	Sep. 25, 2016	Sep. 24, 2017	Sep. 25, 2016
Derivative [Line Items]
Net effect of swaps	$ 952,000	$ (1,650,000)	$ (3,717,000)	$ (8,902,000)
Interest Rate Swap [Member]
Derivative [Line Items]
Amortization of deferred hedge gains	2,400,000	2,400,000	7,100,000	6,300,000
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	(11,800,000)		(11,800,000)
Designated As Hedging [Member]
Derivative [Line Items]
Interest rate cash flow hedge gain (loss) to be reclassified	0		0
Designated As Hedging [Member] | Cash Flow Hedging [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Amount of Gain (Loss) recognized in OCI on Derivatives (Effective Portion)	0	0	0	(4,671,000)
Interest Expense [Member] | Designated As Hedging [Member] | Cash Flow Hedging [Member] | Interest Rate Swap [Member]
Derivative [Line Items]
Amount and Location of Gain (Loss) Reclassified from Accumulated OCI into Income (Effective Portion)	0	0	0	(851,000)
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	$ 3,318,000	$ 715,000	$ 3,378,000	$ (2,596,000)