Partners' Capital (Schedule Of Cash Distribution Activity) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended				12 Months Ended
	Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2011
Cash distribution payment date	Aug. 10, 2012		May 11, 2012		Feb. 10, 2012
Cash distribution per unit	$ 0.4875
Class C Convertible Preferred [Member]
Cash distribution	$ 3,500		3,500		3,424
Cash distribution per unit	$ 0.2100	[1]	0.2100	[1]	0.2054	[1]
General Partner [Member]
Cash distribution	20		20		16
Limited Partner [Member] | Limited Partners-Public Common [Member]
Cash distribution	18,604		17,892		8,344
Limited Partner [Member] | Limited Partners-Affiliated - Common [Member]
Cash distribution					5,368
Limited Partner [Member] | Limited Partners-Affiliated - Subordinated [Member]
Cash distribution	3,484		3,394		3,393
Other Unitholders [Member]
Cash distribution	$ 22,108		21,306		17,121
Cash distribution per unit	$ 0.4875		0.4750		0.4750

[1] Preferred units paid in February 2012 were prorated a quarterly distribution for the portion of the fourth quarter beginning on October 3, 2011 through December 31, 2011 in accordance with the Partnership Agreement.