Consolidated Statements Of Partners' Capital (USD $) In Thousands, except Share data, unless otherwise specified	Number Of Common Units [Member]	Common Unitholders [Member]	General Partners [Member]	Accumulated Other Comprehensive Loss [Member]	Non-Controlling Interests [Member]	Total
Partners' capital, value at Dec. 31, 2008		$ 616,971	$ 16,649	$ (962)	$ 24,804	$ 657,462
Partners' capital, shares at Dec. 31, 2008	39,457,000
Comprehensive income:
Net income (loss)		21,469	(13,406)		(1,885)	6,178
Interest rate swap losses reclassified to interest expense				383	401	784
Interest rate swap loss				(250)	(258)	(508)
Cash contributions			9			9
Contribution for management compensation (Note 11)			14,104			14,104
Cash distributions		(53,876)	(6,204)		(6)	(60,086)
Issuance of units under LTIP, shares	31,000
Issuance of units under LTIP, value		990				990
Partners' capital, value at Dec. 31, 2009		585,554	11,152	(829)	23,056	618,933
Partners' capital, shares at Dec. 31, 2009	39,488,000
Comprehensive income:
Net income (loss)		17,933	(66,392)		(2,082)	(50,541)
Interest rate swap losses reclassified to interest expense				1,035	1,077	2,112
Interest rate swap loss				(206)	(218)	(424)
Cash contributions			2,528		13	2,541
Contribution for management compensation (Note 11)			76,923			76,923
Cash distributions		(58,983)	(11,369)		(7)	(70,359)
Acquisition of noncontrolling interest in DG Marine (Note 3)		(4,920)	(100)		(21,268)	(26,288)
Issuance of units under LTIP, shares	98,000
Issuance of units under LTIP, value		20				20
Issuance of units for cash, shares	5,175,000
Issuance of units for cash, value		116,347				116,347
Issuance of units in exchange for general partner interest, shares (Note 11)	19,854,000
Issuance of units in exchange for general partner interest, value (Note 11)		13,313	(12,742)		(571)
Partners' capital, value at Dec. 31, 2010		669,264				669,264
Partners' capital, shares at Dec. 31, 2010	64,615,000					64,615,000
Comprehensive income:
Net income (loss)		51,249				51,249
Cash distributions		(112,844)				(112,844)
Issuance of units for cash, shares	7,350,000
Issuance of units for cash, value		184,969				184,969
Partners' capital, value at Dec. 31, 2011		$ 792,638				$ 792,638
Partners' capital, shares at Dec. 31, 2011	71,965,000					71,965,000