Unaudited Condensed Consolidated Statement 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]
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax						$ (16,566)
Beginning balance, units (in shares) at Dec. 31, 2014		55,828
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Limited partnership unit options exercised (in shares)		48
Limited partnership unit forfeitures (in shares)		(1)
Issuance of limited partnership units as compensation (in shares)		133
Ending balance, units (in shares) at Jun. 28, 2015		56,008
Beginning balance, value at Dec. 31, 2014		$ 101,556	$ 1	$ 5,936
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ (26,250)	(26,250)
Partnership distribution declared ($1.65 and $1.50 per limited partnership unit)		(84,153)
Expense recognized for limited partnership unit options		353
Tax effect of units involved in treasury unit transactions	2,048	(2,048)
Issuance of limited partnership units as compensation		7,493
Partnership distribution declared			(1)
Period activity, net of tax $3,934 and ($3,136)	5,456					5,456
Period activity, net of tax $92 and $185	(598)						$ (598)
Ending balance, value at Jun. 28, 2015	(3,531)	$ (3,049)	0	5,290	$ (5,772)	11,392	(17,164)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax						(19,300)
Beginning balance, units (in shares) at Dec. 31, 2015		56,018
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Limited partnership unit options exercised (in shares)		10
Limited partnership unit forfeitures (in shares)		0
Issuance of limited partnership units as compensation (in shares)		44
Ending balance, units (in shares) at Jun. 26, 2016		56,072
Beginning balance, value at Dec. 31, 2015	57,009	$ 48,428	0	22,591
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	9,497	9,497
Partnership distribution declared ($1.65 and $1.50 per limited partnership unit)		(92,675)
Expense recognized for limited partnership unit options		5
Tax effect of units involved in treasury unit transactions	1,604	(1,604)
Issuance of limited partnership units as compensation		6,824
Partnership distribution declared			(1)
Period activity, net of tax $3,934 and ($3,136)	(6,844)					(6,844)
Period activity, net of tax $92 and $185	(638)						(638)
Ending balance, value at Jun. 26, 2016	$ (28,427)	$ (29,525)	$ (1)	$ 5,290	$ (4,191)	$ 15,747	$ (19,938)