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)		31
Ending balance, units (in shares) at Jun. 25, 2017		56,240
Beginning balance, value at Dec. 31, 2016		$ 52,288	$ 0			$ 18,891
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ (33,386)	(33,386)
Partnership distribution declared ($1.78 and $1.71 per limited partnership unit)		(96,329)
Reclassification of stranded tax effect		0					0
Expense recognized for limited partnership unit options		0
Tax effect of units involved in treasury unit transactions		(1,377)
Issuance of limited partnership units as compensation		7,889
Net income (loss)			0
Partnership distribution declared			(1)
Period activity, net of tax $2,302 and $0	(1,942)					(1,942)
Period activity, net of tax ($596) and ($742)	3,987						3,987
Ending balance, value at Jun. 25, 2017	(60,640)	$ (70,915)	(1)	$ 5,290	$ 4,986	16,949	(11,963)
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)		(2)
Issuance of limited partnership units as compensation (in shares)		78
Ending balance, units (in shares) at Jun. 24, 2018		56,441
Beginning balance, value at Dec. 31, 2017	82,946	$ 81,589	0			4,042
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	(64,157)	(64,156)
Partnership distribution declared ($1.78 and $1.71 per limited partnership unit)		(100,557)
Reclassification of stranded tax effect		391					(391)
Expense recognized for limited partnership unit options		125
Tax effect of units involved in treasury unit transactions		(3,045)
Issuance of limited partnership units as compensation		(782)
Net income (loss)			(1)
Partnership distribution declared			(1)
Period activity, net of tax $2,302 and $0	11,266					11,266
Period activity, net of tax ($596) and ($742)	4,134						4,134
Ending balance, value at Jun. 24, 2018	$ (70,071)	$ (86,435)	$ (2)	$ 5,290	$ 11,076	$ 15,308	$ (4,232)