Consolidated Balance Sheets (Unaudited) (USD $) In Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2011	Dec. 31, 2010
Current assets:
Cash and cash equivalents	$ 61,556	$ 59,930
Accounts receivable, net	112,641	96,662
Risk management assets	4,616	7,836
Prepayments and other current assets	3,249	5,179
Total current assets	182,062	169,607
Property, plant and equipment, net	1,007,879	912,157
Intangible assets, net	186,872	188,585
Investments in unconsolidated affiliates	658,424	604,304
Escrow cash	1,850	1,856
Risk management assets	12,912	11,943
Other assets, net	28,908	18,541
Total assets	2,078,907	1,906,993
Current liabilities:
Accounts payable	146,178	117,706
Accrued interest	8,037	10,621
Accrued tax liability	586	913
Risk management liabilities	9,784	9,357
Other current liabilities	22,139	14,495
Total current liabilities	186,724	153,092
Long term debt (includes $0 and $546 bond premium as of June 30, 2011 and December 31, 2010, respectively)	804,525	592,736
Deferred tax provision	2,051	1,883
Risk management and other noncurrent liabilities	2,986	4,525
Commitments and contingencies (Note 9)
Members' capital:
Common units, no par value, 66,225,657 units and 65,915,173 units issued and outstanding as of June 30, 2011 and December 31, 2010, respectively	1,164,083	1,161,652
Paid-in capital	57,312	51,743
Accumulated deficit	(396,253)	(313,454)
Accumulated other comprehensive loss	(27,689)	(30,356)
Members' capital	1,082,621	1,154,757
Total liabilities and members' capital	2,078,907	1,906,993
Series A preferred units [Member]
Members' capital:
Series A convertible preferred units, no par value, 11,121,071 units and 10,585,197 units issued and outstanding as of June 30, 2011 and December 31, 2010, respectively	285,168	285,172
Members' capital	$ 285,168	$ 285,172