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]
Beginning balance, units at Dec. 31, 2013		55,716
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Limited partnership unit options exercised		11
Stock Issued During Period, Shares, Restricted Stock Award, Forfeited		0
Issuance of limited partnership units as compensation		132
Ending balance, units at Jun. 29, 2014		55,859
Beginning balance, value at Dec. 31, 2013		$ 148,847	$ 2	$ 5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	$ (39,638)	(39,638)
Partnership distribution declared ($1.50 and $1.40 per limited partnership unit)		(78,275)
Expense recognized for limited partnership unit options		446
Tax effect of units involved in option exercises and treasury unit transactions	725	(725)
Issuance of limited partnership units as compensation		6,263
OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	(696)					$ (696)
OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax	(2,891)						$ (2,891)
Ending balance, value at Jun. 29, 2014	$ 23,615	$ 36,918	2	5,290	$ (18,595)	(691)	(17,904)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Weighted average limited partner units outstanding	55,453
General Partner Distributions	$ 0
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax						(15,013)
Beginning balance, units at Dec. 31, 2014		55,828
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Limited partnership unit options exercised		48
Stock Issued During Period, Shares, Restricted Stock Award, Forfeited		(1)
Issuance of limited partnership units as compensation		133
Ending balance, units at Jun. 28, 2015		56,008
Beginning balance, value at Dec. 31, 2014	96,217	$ 101,556	1	5,936
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(26,250)	(26,250)
Partnership distribution declared ($1.50 and $1.40 per limited partnership unit)		(84,153)
Expense recognized for limited partnership unit options		353
Tax effect of units involved in option exercises and treasury unit transactions	2,048	(2,048)
Issuance of limited partnership units as compensation		7,493
OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax	5,456					5,456
OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax	(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]
Weighted average limited partner units outstanding	55,696
General Partner Distributions	$ (1)
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax						$ (16,566)