Variable Interest Entity (Details 4) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended		3 Months Ended	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2012 As previously reported	Sep. 30, 2012 As previously reported	Dec. 31, 2012 As previously reported
Cash flows from operating activities:
Net income	$ (20,027)	$ (15,265)	$ 44,340	$ 187,042	$ (14,756)	$ 188,653
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	76,323	46,554	215,902	127,472	48,136	132,199
Accretion of asset retirement obligations	160	140	669	536	141	540
Equity in earnings from unconsolidated affiliate	(896)	(706)	(1,561)	(2,254)	(246)	(788)
Distributions from unconsolidated affiliate			4,952	6,624		2,200
Receivables			(37,491)	32,248		32,739
Other current assets			(4,963)	(12,866)		(12,707)
Accounts payable and accrued liabilities			29,664	36,837		36,737
Net cash provided by operating activities			330,659	385,784		389,718
Cash flows from investing activities:
Capital expenditures			(2,176,719)	(1,239,705)		(1,240,866)
Investment in unconsolidated affiliates			(8,530)	(839)
Net cash flows used in investing activities			(2,186,307)	(1,745,749)		(1,746,071)
Cash flows from financing activities:
Contributions from non-controlling interest			685,219	56,101		56,940
Payment of distributions to non-controlling interest			(180)	(71)		(4,495)
Net cash flows provided by financing activities			1,838,045	1,657,986		1,654,401
Net (decrease) increase in cash and cash equivalents			(17,603)	298,021		298,048
Cash and cash equivalents at beginning of year			345,756	114,332		117,016	347,899
Cash and cash equivalents at end of period	$ 328,153	$ 412,353	$ 328,153	$ 412,353	$ 415,064	$ 415,064	$ 347,899