Consolidated Statements of Operations (Unaudited) (USD $) In Thousands, except Share data	3 Months Ended				6 Months Ended
	Jun. 30, 2011		Jun. 30, 2010		Jun. 30, 2011		Jun. 30, 2010
Revenue:
Natural gas sales	$ 123,928		$ 84,819		$ 227,723		$ 205,035
Natural gas liquids sales	180,758		114,802		329,759		234,120
Transportation, compression and processing fees	27,898		16,516		52,369		29,630
Condensate and other	13,472		13,914		26,130		27,932
Total revenue	346,056		230,051		635,981		496,717
Costs and expenses:
Cost of natural gas and natural gas liquids	274,398	[1]	167,613	[1]	498,128	[1]	377,478	[1]
Transportation	6,362	[1]	5,603	[1]	12,211	[1]	11,279	[1]
Operations and maintenance	15,763		13,230		30,862		25,333
Depreciation and amortization	17,363		15,583		34,232		30,784
General and administrative	11,901		10,900		24,499		21,442
Taxes other than income	1,397		1,181		2,527		2,343
Equity in loss (earnings) from unconsolidated affiliates	(1,306)		23,632		(3,008)		21,837
Total costs and expenses	325,878		237,742		599,451		490,496
Operating income (loss)	20,178		(7,691)		36,530		6,221
Other income (expense):
Interest and other income	8		37		15		44
Loss on refinancing of unsecured debt	(18,233)				(18,233)
Interest and other financing costs	(11,454)		(13,351)		(23,370)		(28,296)
Loss before income taxes	(9,501)		(21,005)		(5,058)		(22,031)
Provision for income taxes	140		(106)		(771)		(340)
Net loss	(9,361)		(21,111)		(5,829)		(22,371)
Preferred unit distributions	(8,076)				(15,956)
Net loss (income) to common units	$ (17,437)		$ (21,111)		$ (21,785)		$ (22,371)
Basic and diluted net loss per common unit	$ (0.26)		$ (0.32)		$ (0.33)		$ (0.36)
Weighted average number of common units	66,143		65,516		66,065		61,941
Distributions declared per common unit	$ 0.575		$ 0.575		$ 1.150		$ 1.150

[1] Exclusive of operations and maintenance and depreciation and amortization shown separately below.