Supplemental Condensed Consolidating Financial Information (Details 3) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Condensed Consolidating Statements of Cash Flows
Net cash (used in) provided by operating activities	$ 200,934	$ 112,373
Cash flows from investing activities:
Restricted cash	10,000	0
Capital expenditures	(438,271)	(587,120)
Investment in unconsolidated affiliates	(47,426)	(7,498)
Proceeds from disposal of property, plant and equipment	857	19,144
Net cash flows used in investing activities	(474,840)	(575,474)
Cash flows from financing activities:
Proceeds from public equity offerings, net	0	271,880
Proceeds from Credit Facility	601,900	377,300
Payments of Credit Facility	(699,500)	0
Proceeds from long-term debt	660,563	0
Payments for debt issuance costs, deferred financing costs and registration costs	(7,000)	(1,890)
Proceeds from sale of equity interest in consolidated subsidiary	10,823	0
Contributions from non-controlling interest	19,571	0
Payments of SMR liability	(652)	(594)
Share-based payment activity	(6,117)	(8,924)
Payment of distributions	(178,285)	(136,495)
Net cash flows provided by financing activities	401,303	501,277
Net increase in cash and cash equivalents	127,397	38,176
Cash and cash equivalents at beginning of period	108,887	85,305
Cash and cash equivalents at end of period	236,284	123,481
Reportable legal entities | Parent
Condensed Consolidating Statements of Cash Flows
Net cash (used in) provided by operating activities	(61,211)	(56,688)
Cash flows from investing activities:
Capital expenditures	(695)	(3,512)
Equity investment in consolidated affiliates	(17,640)	(14,243)
Intercompany advances, net	(235,245)	(445,203)
Distributions from consolidated affiliates	21,663	35,861
Investment in intercompany notes receivable, net	(27,000)	(18,400)
Net cash flows used in investing activities	(258,917)	(445,497)
Cash flows from financing activities:
Proceeds from public equity offerings, net		271,880
Proceeds from Credit Facility	601,900	377,300
Payments of Credit Facility	(699,500)
Proceeds from long-term debt	660,563
Payments for debt issuance costs, deferred financing costs and registration costs	(7,000)	(1,890)
Share-based payment activity	(6,117)	(8,924)
Payment of distributions	(168,718)	(136,405)
Net cash flows provided by financing activities	381,128	501,961
Net increase in cash and cash equivalents	61,000	(224)
Cash and cash equivalents at beginning of period		224
Cash and cash equivalents at end of period	61,000
Reportable legal entities | Guarantor Subsidiaries
Condensed Consolidating Statements of Cash Flows
Net cash (used in) provided by operating activities	59,387	103,777
Cash flows from investing activities:
Capital expenditures	(40,384)	(51,417)
Equity investment in consolidated affiliates	(408,037)	(522,200)
Investment in unconsolidated affiliates	(6,632)	(7,498)
Distributions from consolidated affiliates	138,750	73,610
Proceeds from disposal of property, plant and equipment	19	2,043
Net cash flows used in investing activities	(316,284)	(505,462)
Cash flows from financing activities:
Payments related to intercompany financing, net	27,000	18,400
Contributions from Parent and affiliates	17,640	14,243
Payments of SMR liability	(652)	(594)
Payment of distributions	(21,663)	(35,861)
Intercompany advances, net	247,922	445,203
Net cash flows provided by financing activities	270,247	441,391
Net increase in cash and cash equivalents	13,350	39,706
Cash and cash equivalents at beginning of period		79,363
Cash and cash equivalents at end of period	13,350	119,069
Reportable legal entities | Non-Guarantor Subsidiaries
Condensed Consolidating Statements of Cash Flows
Net cash (used in) provided by operating activities	198,899	64,456
Cash flows from investing activities:
Restricted cash	10,000
Capital expenditures	(393,117)	(530,853)
Intercompany advances, net	(12,320)
Investment in unconsolidated affiliates	(40,794)
Proceeds from disposal of property, plant and equipment	838	17,101
Net cash flows used in investing activities	(435,393)	(513,752)
Cash flows from financing activities:
Payments related to intercompany financing, net	(573)	(510)
Proceeds from sale of equity interest in consolidated subsidiary	10,823
Contributions from non-controlling interest	19,571
Contributions from Parent and affiliates	408,037	522,200
Payment of distributions	(148,317)	(73,700)
Net cash flows provided by financing activities	289,541	447,990
Net increase in cash and cash equivalents	53,047	(1,306)
Cash and cash equivalents at beginning of period	108,887	5,718
Cash and cash equivalents at end of period	161,934	4,412
Eliminations
Condensed Consolidating Statements of Cash Flows
Net cash (used in) provided by operating activities	3,859	828
Cash flows from investing activities:
Capital expenditures	(4,075)	(1,338)
Equity investment in consolidated affiliates	425,677	536,443
Intercompany advances, net	247,565	445,203
Distributions from consolidated affiliates	(160,413)	(109,471)
Investment in intercompany notes receivable, net	27,000	18,400
Net cash flows used in investing activities	535,754	889,237
Cash flows from financing activities:
Payments related to intercompany financing, net	(26,427)	(17,890)
Contributions from Parent and affiliates	(425,677)	(536,443)
Payment of distributions	160,413	109,471
Intercompany advances, net	(247,922)	(445,203)
Net cash flows provided by financing activities	$ (539,613)	$ (890,065)