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]
Beginning balance, units (in shares) at Dec. 31, 2017		56,359
Beginning balance, value at Dec. 31, 2017	$ 82,946	$ 81,589	$ 0	$ 5,290	$ (3,933)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(83,400)	(83,399)	(1)
Partnership distribution declared	(50,266)	$ (50,266)	0
Issuance of limited partnership units as compensation (in shares)		57
Issuance of limited partnership units as compensation	(3,826)	$ (3,826)
Tax effect of units involved in treasury unit transactions	(3,039)	(3,039)
Foreign currency translation adjustment	4,604				4,604
Cash flow hedging derivative activity, net of tax ($347)	2,018				2,018
Reclassification of stranded tax effect	0	$ 391			(391)
Ending balance, units (in shares) at Mar. 25, 2018		56,416
Ending balance, value at Mar. 25, 2018	(50,963)	$ (58,550)	(1)	5,290	2,298
Beginning balance, units (in shares) at Dec. 31, 2018		56,564
Beginning balance, value at Dec. 31, 2018	32,416	$ 5,845	(1)	5,290	21,282
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(83,673)	(83,672)	(1)
Partnership distribution declared	(52,334)	$ (52,334)	0
Issuance of limited partnership units as compensation (in shares)		23
Issuance of limited partnership units as compensation	(1,536)	$ (1,536)
Tax effect of units involved in treasury unit transactions	(1,421)	$ (1,421)
Foreign currency translation adjustment	(3,050)				(3,050)
Ending balance, units (in shares) at Mar. 31, 2019		56,587
Ending balance, value at Mar. 31, 2019	$ (109,598)	$ (133,118)	$ (2)	$ 5,290	$ 18,232