Consolidated Statement Of Changes In Partners' Capital (USD $) In Thousands	Class C Convertible Preferred [Member]	General Partner [Member]	Class B Convertible Unitholder [Member]	Limited Partners-Public Common [Member]	Limited Partners-Affiliated - Common [Member]	Total
Balances at Dec. 31, 2012	$ 373,068	$ 710		$ 403,757	$ (62,971)	$ 714,564
Recognition of unit-based awards				1,026		1,026
Unit issuance costs				(78)		(78)
Distributions to unitholders	(3,500)	(25)	(2,990)	(25,275)	(3,484)	(35,274)
Amortization of discount on increasing rate distributions	3,829					3,829
Noncash distribution to preferred unitholders	(3,829)					(3,829)
Management incentive fee earned		(748)				(748)
Other		1		710	(607)	104
Net income (loss)	7,329	734	2,990	(17,497)	(1,730)	(8,174)
Balances at Mar. 31, 2013	$ 376,897	$ 672		$ 362,643	$ (68,792)	$ 671,420