CONSOLIDATED STATEMENT OF CHANGES IN PARTNERS CAPITAL (USD $) In Thousands, unless otherwise specified	Total	General Partner Preferred Units	General Partner Units	Limited Partner Units	Accumulated Other Comprehensive Loss
Balance at Dec. 31, 2012	$ 1,155,151	$ 217,971	$ 859,727	$ 84,282	$ (6,829)
Increase (Decrease) in Partners' Capital [Roll Forward]
Issuance of General Partner Units, Net of Issuance Costs	173,820		173,820
Redemption of Preferred Units	(96,479)	(96,479)
Stock Based Compensation Activity	1,222		1,222
Conversion of Limited Partner Units to General Partner Units	0		804	(804)
Common Unit Distributions	(19,286)		(18,494)	(792)
Preferred Unit Distributions	(9,660)	(9,660)
Net Income	10,265	9,660	580	25
Other Comprehensive Income	2,238				2,238
Balance at Jun. 30, 2013	$ 1,217,271	$ 121,492	$ 1,017,659	$ 82,711	$ (4,591)