Unaudited Condensed Consolidated Statements of Partners' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Limited Partners [Member]	General Partner [Member]	Special L.P. Interests [Member]	AOCI Attributable to Parent [Member]	Accumulated Translation Adjustment [Member]	Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Unrealized gain (loss) on cash flow hedging derivatives: Beginning balance							$ (15,950)
Beginning balance, units (in shares) at Dec. 31, 2016		56,201
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Limited partnership unit options exercised (in shares)		10
Limited partnership unit forfeitures (in shares)		(2)
Issuance of limited partnership units as compensation (in shares)		27
Ending balance, units (in shares) at Mar. 26, 2017		56,236
Beginning balance, value at Dec. 31, 2016		$ 52,288	$ 0			$ 18,891
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ (64,754)	(64,753)
Partnership distribution declared ($0.890 and $0.855 per limited partnership unit)		(48,135)
Reclassification of stranded tax effect		0					0
Expense recognized for limited partnership unit options		0
Tax effect of units involved in treasury unit transactions		(1,369)
Issuance of limited partnership units as compensation		4,853
Net income (loss)			(1)
Partnership distribution declared			0
Period activity, net of tax $1,145 and $0	(660)					(660)
Period activity, net of tax ($347) and ($371)	1,994						1,994
Ending balance, value at Mar. 26, 2017	(47,552)	$ (57,116)	(1)	$ 5,290	$ 4,275	18,231	(13,956)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Unrealized gain (loss) on cash flow hedging derivatives: Beginning balance							(7,975)
Beginning balance, units (in shares) at Dec. 31, 2017		56,359
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Limited partnership unit options exercised (in shares)		6
Limited partnership unit forfeitures (in shares)		(1)
Issuance of limited partnership units as compensation (in shares)		52
Ending balance, units (in shares) at Mar. 25, 2018		56,416
Beginning balance, value at Dec. 31, 2017	82,946	$ 81,589	0			4,042
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	(83,400)	(83,399)
Partnership distribution declared ($0.890 and $0.855 per limited partnership unit)		(50,266)
Reclassification of stranded tax effect	400	391					391
Expense recognized for limited partnership unit options		125
Tax effect of units involved in treasury unit transactions		(3,039)
Issuance of limited partnership units as compensation		(3,951)
Net income (loss)			(1)
Partnership distribution declared			0
Period activity, net of tax $1,145 and $0	4,604					4,604
Period activity, net of tax ($347) and ($371)	2,018						2,018
Ending balance, value at Mar. 25, 2018	$ (50,963)	$ (58,550)	$ (1)	$ 5,290	$ 2,298	$ 8,646	$ (6,348)