Changes in Accumulated Other Comprehensive Income by Component (Reclassifications Out of AOCI) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 24, 2018	Jun. 30, 2019	Jun. 24, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net effect of swaps	$ (22,846)	$ (21,282)	$ (43,533)	$ (40,818)
Provision (benefit) for taxes	(14,676)	(13,730)	5,309	5,469
Net income (loss)	63,298	19,243	(20,375)	(64,157)
Cash Flow Hedging Derivative Activity [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Provision (benefit) for taxes	0		0
Net income (loss)	0		0
Cash Flow Hedging Derivative Activity [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Provision (benefit) for taxes		(249)		(596)
Net income (loss)		2,116		4,134
Interest Rate Swap [Member] | Cash Flow Hedging Derivative Activity [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net effect of swaps	$ 0		$ 0
Interest Rate Swap [Member] | Cash Flow Hedging Derivative Activity [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net effect of swaps		$ 2,365		$ 4,730