Consolidated Statement Of Changes In Equity (USD $) In Thousands	Common Equity	Preferred Equity	Limited Partners' Common Equity	Accumulated Other Comprehensive Income (Loss)	Total Partners' Equity	Noncontrolling Interests	Total
Balance at Dec. 31, 2010	$ 2,046,617	$ 904,540	$ 34,894	$ (1,432)	$ 2,984,619	$ 5,226	$ 2,989,845
Comprehensive income:
Net income	18,690	31,948	499		51,137	(206)	50,931
Derivative instrument activity				1,488	1,488		1,488
Comprehensive income					52,625	(206)	52,419
Issuance of Limited Partner Units for acquisition			28,357		28,357		28,357
Conversion of Limited Partner Units to common shares of the General Partner	1,235		(1,235)				1,235
Repurchase of Preferred Units	(96)	(2,000)			(2,096)		(2,096)
Stock based compensation plan activity	6,378				6,378		6,378
Distribution to Preferred Unitholders		(31,948)			(31,948)		(31,948)
Distributions to Partners ($.34 per Common Unit)	(85,879)		(2,340)		(88,219)		(88,219)
Distributions to noncontrolling interests						(58)	(58)
Balance at Jun. 30, 2011	$ 1,986,945	$ 902,540	$ 60,175	$ 56	$ 2,949,716	$ 4,962	$ 2,954,678
Common Units outstanding at June 30, 2011 at Jun. 30, 2011	252,663		7,190		259,853