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, 2011
Distributions to unitholders	$ (3,500)	$ (25)		$ (25,275)	$ (3,484)
Balances at Dec. 31, 2012	373,068	710		403,757	(62,971)
Distributions to unitholders	(3,500)	(25)		(25,480)	(3,484)
Balances at Mar. 31, 2013
Balances at Dec. 31, 2012	373,068	710		403,757	(62,971)	714,564
Recognition of unit-based awards				3,185		3,185
Unit issuance costs				(78)		(78)
Distributions to unitholders	(7,000)	(50)	(5,980)	(50,755)	(6,967)	(70,752)
Amortization of discount on increasing rate distributions	7,697					7,697
Noncash distribution to preferred unitholders	(7,697)					(7,697)
Management incentive fee earned		(748)				(748)
Other		1		1,142	(728)	415
Net income	14,697	770	5,980	29,191	4,802	55,440
Balances at Jun. 30, 2013	$ 380,765	$ 683		$ 386,442	$ (65,864)	$ 702,026