Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Current Assets:
Cash and cash equivalents	$ 990	$ 9,400
Trade accounts receivable, net of allowance of $1,190 and $297	43,917	35,212
Accrued revenues	68,011	74,017
Related party receivables	45,204	32,342
Derivative assets	4,374	2,650
Other current assets	24,628	7,384
Total current assets	187,124	161,005
Property, Plant and Equipment:
Gathering and transmission systems	698,906	543,286
Compression equipment	846,914	812,428
Gas plants and buildings	195,231	185,741
Other property, plant and equipment	147,967	81,295
Construction-in-progress	191,914	97,439
Total property, plant and equipment	2,080,932	1,720,189
Less accumulated depreciation	(195,404)	(59,971)
Property, plant and equipment, net	1,885,528	1,660,218
Other Assets:
Investment in unconsolidated affiliates	1,924,705	1,351,256
Long-term derivative assets	474	23
Other, net of accumulated amortization of debt issuance costs of $10,186 and $3,326	39,353	37,758
Total other assets	1,964,532	1,389,037
Intangible Assets and Goodwill:
Intangible assets, net of accumulated amortization of $44,856 and $15,584	740,883	770,155
Goodwill	789,789	789,789
Total intangible assets and goodwill	1,530,672	1,559,944
TOTAL ASSETS	5,567,856	4,770,204
Current Liabilities:
Drafts Payable	2,507	0
Trade accounts payable	73,462	50,208
Accrued cost of gas and liquids	84,943	80,756
Related party payables	12,625	3,338
Deferred revenues, including related party amounts of $41 and $8,765	16,225	25,257
Derivative liabilities	10,535	13,172
Other current liabilities	33,009	23,419
Total current liabilities	233,306	196,150
Long-term derivative liabilities	39,112	61,127
Other long-term liabilities	6,071	6,521
Long-term debt, net	1,687,147	1,141,061
Commitments and contingencies
Series A Preferred Units, redemption amount of $84,773 and $83,891	71,144	70,943
Partners' Capital and Noncontrolling Interest:
Common units (161,233,046 and 138,255,919 units authorized; 157,437,608 and 137,281,336 units issued and outstanding at December 31, 2011 and December 31, 2010)	3,173,090	2,940,732
General partner interest	329,876	333,077
Accumulated other comprehensive loss	(4,759)	(11,099)
Total partners' capital	3,498,207	3,262,710
Noncontrolling interest	32,869	31,692
Total partners' capital and noncontrolling interest	3,531,076	3,294,402
TOTAL LIABILITIES AND PARTNERS' CAPITAL AND NONCONTROLLING INTEREST	$ 5,567,856	$ 4,770,204