Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Cash flows from operating activities:
Net (loss) income	$ (20,764)	$ 16,273
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	69,597	41,145
Amortization of intangible assets	14,830	10,985
Loss on redemption of debt	38,455
Amortization of deferred financing costs and discount	1,830	1,270
Accretion of asset retirement obligations	353	238
Amortization of deferred contract cost	78	78
Phantom unit compensation expense	4,002	5,709
Equity in loss of unconsolidated affiliate	85	9
Distributions from unconsolidated affiliate		900
Unrealized (gain) loss on derivative instruments	(9,033)	48,217
Loss on disposal of property, plant and equipment	138	986
Deferred income taxes	11,971	(10,796)
Changes in operating assets and liabilities, net of working capital acquired:
Receivables	(14,026)	30,279
Inventories	4,119	23,812
Other current assets	10,983	3,503
Accounts payable and accrued liabilities	(30,561)	32,556
Other long-term assets	33	61
Other long-term liabilities	2,953	2,688
Net cash provided by operating activities	85,043	207,913
Cash flows from investing activities:
Restricted cash	25,000	1,003
Capital expenditures	(631,558)	(254,263)
Investment in unconsolidated affiliate	(3,012)
Proceeds from disposal of property, plant and equipment	209	291
Net cash flows used in investing activities	(609,361)	(252,969)
Cash flows from financing activities:
Proceeds from public equity offerings, net	103,937	425,629
Proceeds from Credit Facility		13,700
Payments of Credit Facility		(79,700)
Proceeds from long-term debt	1,000,000
Payments of long-term debt	(501,112)
Payments of premiums on redemption of long-term debt	(31,516)
Payments for debt issuance costs, deferred financing costs and registration costs	(14,046)
Contributions from non-controlling interest	385,219	755
Payments of SMR liability	(545)	(497)
Cash paid for taxes related to net settlement of share-based payment awards	(5,206)	(8,048)
Excess tax benefits related to share-based compensation	651	2,207
Payment of distributions to common unitholders	(105,945)	(73,410)
Payment of distributions to non-controlling interest	(848)	(1,962)
Net cash flows provided by financing activities	830,589	278,674
Net increase in cash and cash equivalents	306,271	233,618
Cash and cash equivalents at beginning of year	347,899	117,016
Cash and cash equivalents at end of period	$ 654,170	$ 350,634