Partners' Capital (Schedule Of Cash Distribution Activity) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended						12 Months Ended
	Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2011
Partners' Cash Distribution Activity [Line Items]
Cash distribution payment date	Nov. 09, 2012		Aug. 10, 2012		May 11, 2012		Feb. 10, 2012
Cash distribution per unit	$ 0.4875
Class C Convertible Preferred [Member]
Partners' Cash Distribution Activity [Line Items]
Cash distribution	$ 3,500		3,500		3,500		3,424
Cash distribution per unit	$ 0.2100	[1],[2]	0.2100	[1],[2]	0.2100	[1],[2]	0.2054	[1],[2]
General Partner [Member]
Partners' Cash Distribution Activity [Line Items]
Cash distribution	20		20		20		16
Limited Partner [Member] | Limited Partners-Public Common [Member]
Partners' Cash Distribution Activity [Line Items]
Cash distribution	18,624		18,584		17,892		8,344
Limited Partner [Member] | Limited Partners-Affiliated - Common [Member]
Partners' Cash Distribution Activity [Line Items]
Cash distribution							5,368
Limited Partner [Member] | Limited Partners-Affiliated - Subordinated [Member]
Partners' Cash Distribution Activity [Line Items]
Cash distribution	3,484		3,484		3,394		3,393
Other Unitholders [Member]
Partners' Cash Distribution Activity [Line Items]
Cash distribution	$ 22,128		22,088		21,306		17,121
Cash distribution per unit	$ 0.4875		0.4875		0.4750		0.4750

[1] (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.

[2] 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.