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)		9
Limited partnership unit forfeitures (in shares)		(3)
Issuance of limited partnership units as compensation (in shares)		31
Ending balance, units (in shares) at Sep. 24, 2017		56,238
Beginning balance, value at Dec. 31, 2016		$ 52,288	$ 0			$ 18,891
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	$ 157,929	157,928
Partnership distribution declared ($2.67 and $2.565 per limited partnership unit)		(144,516)
Reclassification of stranded tax effect		0					0
Exercise of limited partnership unit options	0	0
Tax effect of units involved in treasury unit transactions		(2,560)
Issuance of limited partnership units as compensation		11,015
Net income (loss)			1
Partnership distribution declared			(1)
Period activity, net of tax $1,247 and $0	(13,085)					(13,085)
Period activity, net of tax ($845) and ($1,113)	5,981						5,981
Ending balance, value at Sep. 24, 2017	75,282	$ 74,155	0	$ 5,290	$ (4,163)	5,806	(9,969)
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 Sep. 23, 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	149,150	149,148
Partnership distribution declared ($2.67 and $2.565 per limited partnership unit)		(150,850)
Reclassification of stranded tax effect		391					(391)
Exercise of limited partnership unit options	125	(125)
Tax effect of units involved in treasury unit transactions		(3,049)
Issuance of limited partnership units as compensation		1,110
Net income (loss)			2
Partnership distribution declared			(2)
Period activity, net of tax $1,247 and $0	5,990					5,990
Period activity, net of tax ($845) and ($1,113)	6,250						6,250
Ending balance, value at Sep. 23, 2018	$ 91,670	$ 78,464	$ 0	$ 5,290	$ 7,916	$ 10,032	$ (2,116)