Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	7 Months Ended	12 Months Ended	5 Months Ended	12 Months Ended
	Dec. 31, 2010 Successor [Member]	Dec. 31, 2011 Successor [Member]	May 25, 2010 Predecessor [Member]	Dec. 31, 2009 Predecessor [Member]
OPERATING ACTIVITIES:
Net income (loss)	$ (5,972)	$ 73,619	$ (4,946)	$ 140,489
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	79,323	174,630	49,363	116,307
Write-off of debt issuance costs and bond premium	(1,422)	0	1,780	0
Amortization of excess fair value of unconsoildated affilaites	3,410	5,847	0	0
Income from unconsolidated affiliates	(56,903)	(125,387)	(15,872)	(7,886)
Derivative valuation changes	33,189	(20,486)	12,004	5,163
(Gain) loss on asset sales, net	268	(2,372)	303	(133,284)
Unit-based compensation expenses	1,827	3,610	12,070	6,008
Cash flow changes in current assets and liabilities:
Trade accounts receivable, accrued revenues and related party receivables	(401)	(8,328)	(11,272)	10,727
Other current assets	(107)	734	2,516	10,471
Trade accounts payable, accrued cost of gas and liquids, related party payables and deferred revenues	(15,302)	23,221	8,649	(3,762)
Other current liabilities	(12,853)	9,590	22,614	(6,726)
Distributions received from unconsolidated affiliates	56,903	119,236	12,446	7,886
Cash flow changes in other assets and liabilities	(2,174)	(159)	(234)	(1,433)
Net cash flows provided by operating activities	79,786	253,755	89,421	143,960
INVESTING ACTIVITIES:
Capital expenditures	(159,223)	(406,339)	(63,787)	(193,083)
Capital contributions to unconsolidated affiliates	(85,828)	(52,601)	(20,210)	0
Distributions in excess of earnings of unconsolidated affiliates	59,066	73,476	0	1,039
Acquisition of investment in unconsolidated affiliates, net of cash received	4,632	(593,843)	(75,114)	0
Acquisitions, net of cash $0, $1,983, $0, and $0	(191,313)	0	0	(52,803)
Net proceeds from asset sales	76,237	24,024	10,661	88,682
Net cash flows used in investing activities	(296,429)	(955,283)	(148,450)	(156,165)
FINANCING ACTIVITIES:
Net borrowings (repayments) under revolving credit facility	(333,650)	47,000	199,008	(349,087)
Proceeds from issuance of senior notes	600,000	500,000	0	236,240
Redemption of senior notes	(357,500)	0	0	0
Debt issuance costs	(12,389)	(9,768)	(15,728)	(12,224)
Partner contributions	27,999	0	0	6,344
Partner distributions	(118,630)	(274,488)	(86,078)	(146,585)
Acquisition of assets between entities under common control in excess of historical cost	0	72	(16,973)	(10,197)
Contributions from noncontrolling interest	86	0	0	0
Distributions to noncontrolling interest	0	0	(1,135)	0
Drafts payable	0	2,507	0	0
(Payments) proceeds associated with issuance of common units under LTIP, net of tax withholding	1,452	(109)	(4,874)	0
Proceeds from common unit issuances, net of issuance costs	399,582	435,685	(89)	220,318
Proceeds from Series A Preferred Units issuance, net of issuance costs	0	0	0	76,624
Distributions to Series A Preferred Units	(3,891)	(7,781)	(1,945)	0
Net cash flows provided by financing activities	203,059	693,118	72,186	21,433
Net change in cash and cash equivalents	(13,584)	(8,410)	13,157	9,228
Cash and cash equivalents at beginning of period	22,984	9,400	9,827	599
Cash and cash equivalents at end of period	9,400	990	22,984	9,827
Supplemental cash flow information:
Non-cash capital expenditures	19,635	24,111	18,051	9,688
Issuance of common units for investment in unconsolidated affiliate	584,436	0	0	0
Deemed contribution from acquisition of assets between entities under common control	8,937	177	0	0
Release of escrow payable from restricted cash	1,011	0	500	8,501
Interest paid, net of amounts capitalized	58,335	82,602	5,410	69,401
Income taxes paid	937	1,778	378	6
Contribution of RIG to HPC	0	0	0	263,921
Non-cash proceeds from contribution of RIG to HPC	0	0	0	403,568
Distributions accrued but not paid to Series A Preferred Units	$ 0	$ 0	$ 0	$ 3,891