Condensed Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
OPERATING ACTIVITIES:
Net income	$ 58,227	$ 29,142
Adjustments to reconcile net income (loss) to net cash flows provided by operating activities:
Depreciation and amortization, including debt issuance cost, amortization and bond premium amortization	99,359	83,587
Income from unconsolidated affiliates	(66,143)	(55,975)
Derivative valuation changes	(24,450)	(5,826)
Loss on asset sales, net	1,584	181
Unit-based compensation expenses	2,294	1,747
Cash flow changes in current assets and liabilities:
Trade accounts receivable, accrued revenues and related party receivables	21,052	(8,847)
Other current assets	179	964
Trade accounts payable, accrued cost of gas and liquids, related party payables and deferred revenues	(51,903)	28,577
Other current liabilities	(976)	(2,764)
Distributions received from unconsolidated affiliates	63,096	50,510
Other assets and liabilities	(123)	(182)
Net cash flows provided by operating activities	102,196	121,114
INVESTING ACTIVITIES:
Capital expenditures	(197,941)	(172,236)
Capital contributions to unconsolidated affiliates	(169,751)	(591,681)
Distribution in excess of earnings of unconsolidated affiliates	22,859	27,990
Proceeds from asset sales	20,411	4,003
Net cash flows used in investing activities	(324,422)	(731,924)
FINANCING ACTIVITIES:
Net borrowings under revolving credit facility	183,000	45,000
Proceeds from issuance of senior notes	0	500,000
Redemption of senior notes	(87,500)	0
Debt issuance costs	(686)	(9,936)
Drafts payable	(2,158)	0
Partner distributions	(158,226)	(131,106)
Disposition of assets between entities under common control in excess of historical cost	136	25
Contributions from noncontrolling interest	9,834	0
Issuance of common units under LTIP, net of forfeitures and tax withholding	(207)	506
Common unit offering, net of costs	296,817	203,917
Distributions to Series A Preferred Units	(3,891)	(3,891)
Net cash flows provided by financing activities	237,119	604,515
Net change in cash and cash equivalents	14,893	(6,295)
Cash and cash equivalents at beginning of period	990	9,400
Cash and cash equivalents at end of period	15,883	3,105
Non-cash Investing Activities:
Accrued capital expenditures and contributions to unconsolidated affiliates	$ 58,940	$ 14,598