Condensed Consolidating Statements of Cash Flows (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Condensed Financial Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	$ (89,635)	$ 42,965	$ (28,717)
Cash flows from investing activities:
Cash paid in connection with acquisitions, net of cash acquired	(591,011)	(30,023)	0
Cash paid to acquire non-marketable securities	0	(20,000)	0
Loans to subsidiaries	0	0
Loans to Parent	0
Intercompany advances made	0	0	0
Repayments from subsidiaries	0
Investment in subsidiaries	0		0
Notes receivable to non-guarantor	0
Repayments of notes receivable from non-guarantor	0
Investment in joint ventures	(33,044)	0	0
Deposits	(3,999)	2,897	(26,200)
Capital expenditures	(791,469)	(302,180)	(33,129)
Acquisition of exploration rights	(8,167)	0	0
Other investing activities	4,761	(84)	(102)
Net cash used in investing activities	(1,422,929)	(349,390)	(59,431)
Cash flows from financing activities:
Capital contributions	390,093	0	15,000
Capital contributions from parent company	0		0
Repayments of short-term borrowings—related party	0	(3,150)	(1,107)
Net proceeds from sale of common stock in conjunction with initial public offering			378,633
Repayments of debt	(228,708)	(4,428)	0
Net proceeds from sale of preferred stock	0	199,642	0
Net proceeds from sale of common stock	132,130	0	378,633
Issuance of 10% Senior Secured Notes	635,373	0	0
Issuance of Convertible Notes	395,712	223,100
Proceeds from short-term borrowings—related party			5,008
Payments of preferred dividends	(11,385)	(9,015)	0
Dividend paid to noncontrolling interests	(5,977)	0	0
Proceeds from debt	14,699	5,131	0
Borrowings from parent	0	0
Repayments of borrowings to parent	0
Borrowing from guarantor	0
Repayments of borrowings to guarantor	0
Intercompany advances owed	0	0	0
Other financing activities	(1,554)	0	115
Net cash provided by financing activities	1,320,383	411,280	397,649
Effect of exchange rate changes on cash	1,116	(2,430)	0
Net change in cash and cash equivalents	(191,065)	102,425	309,501
Cash and cash equivalents at beginning of the period	418,855	316,430	6,929
Cash and cash equivalents at end of period	227,790	418,855	316,430
Parent
Condensed Financial Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	(13,207)	903	(187)
Cash flows from investing activities:
Cash paid in connection with acquisitions, net of cash acquired	0	0
Cash paid to acquire non-marketable securities		0
Loans to subsidiaries	(683,063)	(49,430)
Loans to Parent	0
Intercompany advances made	(1,009,014)	(290,633)	(43,931)
Repayments from subsidiaries	87,824
Investment in subsidiaries	(350,000)		(15,000)
Notes receivable to non-guarantor	0
Repayments of notes receivable from non-guarantor	0
Investment in joint ventures	0
Deposits	0	16,449	(18,200)
Capital expenditures	0	0	0
Acquisition of exploration rights	0
Other investing activities	0	0	0
Net cash used in investing activities	(1,954,253)	(323,614)	(77,131)
Cash flows from financing activities:
Capital contributions	390,093		15,000
Capital contributions from parent company	0		0
Repayments of short-term borrowings—related party		0	0
Net proceeds from sale of common stock in conjunction with initial public offering			378,633
Repayments of debt		0
Net proceeds from sale of preferred stock		199,642
Net proceeds from sale of common stock	132,130
Issuance of 10% Senior Secured Notes	635,373
Issuance of Convertible Notes	395,712	223,100
Proceeds from short-term borrowings—related party			0
Payments of preferred dividends	(11,385)	(9,015)
Dividend paid to noncontrolling interests
Proceeds from debt	0	0
Borrowings from parent	0	0
Repayments of borrowings to parent	0
Borrowing from guarantor	37,589
Repayments of borrowings to guarantor	0
Intercompany advances owed	0	0	0
Other financing activities	(2,938)		115
Net cash provided by financing activities	1,576,574	413,727	393,748
Effect of exchange rate changes on cash	0	0
Net change in cash and cash equivalents	(390,886)	91,016	316,430
Cash and cash equivalents at beginning of the period	407,446	316,430	0
Cash and cash equivalents at end of period	16,560	407,446	316,430
Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	(112,386)	44,211	(28,530)
Cash flows from investing activities:
Cash paid in connection with acquisitions, net of cash acquired	0	(30,128)
Cash paid to acquire non-marketable securities		(20,000)
Loans to subsidiaries	0	0
Loans to Parent	(37,589)
Intercompany advances made	0	0	0
Repayments from subsidiaries	0
Investment in subsidiaries	0		0
Notes receivable to non-guarantor	(227,512)
Repayments of notes receivable from non-guarantor	110,000
Investment in joint ventures	(27,680)
Deposits	(3,999)	(13,552)	(8,000)
Capital expenditures	(766,951)	(294,010)	(33,129)
Acquisition of exploration rights	0
Other investing activities	0	16	(102)
Net cash used in investing activities	(953,731)	(357,674)	(41,231)
Cash flows from financing activities:
Capital contributions	0		0
Capital contributions from parent company	0		15,000
Repayments of short-term borrowings—related party		(3,150)	(1,107)
Net proceeds from sale of common stock in conjunction with initial public offering			0
Repayments of debt	(870)	0
Net proceeds from sale of preferred stock		0
Net proceeds from sale of common stock	0
Issuance of 10% Senior Secured Notes	0
Issuance of Convertible Notes	0	0
Proceeds from short-term borrowings—related party			5,008
Payments of preferred dividends	0	0
Dividend paid to noncontrolling interests	0
Proceeds from debt	0	0
Borrowings from parent	227,512	37,370
Repayments of borrowings to parent	(34,327)
Borrowing from guarantor	0
Repayments of borrowings to guarantor	0
Intercompany advances owed	881,179	290,001	43,931
Other financing activities	(115)		0
Net cash provided by financing activities	1,073,379	324,221	62,832
Effect of exchange rate changes on cash	0	0
Net change in cash and cash equivalents	7,262	10,758	(6,929)
Cash and cash equivalents at beginning of the period	10,758	0	6,929
Cash and cash equivalents at end of period	18,020	10,758	0
Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	35,958	(2,149)
Cash flows from investing activities:
Cash paid in connection with acquisitions, net of cash acquired	(591,011)	105
Cash paid to acquire non-marketable securities		0
Loans to subsidiaries	0	0
Loans to Parent	0
Intercompany advances made	0	0
Repayments from subsidiaries	0
Investment in subsidiaries	0
Notes receivable to non-guarantor	0
Repayments of notes receivable from non-guarantor	0
Investment in joint ventures	(5,364)
Deposits	0	0
Capital expenditures	(24,518)	(8,170)
Acquisition of exploration rights	(8,167)
Other investing activities	4,761	(100)
Net cash used in investing activities	(624,299)	(8,165)	0
Cash flows from financing activities:
Capital contributions	0
Capital contributions from parent company	350,000
Repayments of short-term borrowings—related party		0
Repayments of debt	(227,838)	(4,428)
Net proceeds from sale of preferred stock		0
Net proceeds from sale of common stock	0
Issuance of 10% Senior Secured Notes	0
Issuance of Convertible Notes	0	0
Payments of preferred dividends	0	0
Dividend paid to noncontrolling interests	(5,977)
Proceeds from debt	14,699	5,131
Borrowings from parent	455,551	12,060
Repayments of borrowings to parent	(53,497)
Borrowing from guarantor	227,512
Repayments of borrowings to guarantor	(110,000)
Intercompany advances owed	127,835	632
Other financing activities	1,499
Net cash provided by financing activities	779,784	13,395	0
Effect of exchange rate changes on cash	1,116	(2,430)
Net change in cash and cash equivalents	192,559	651
Cash and cash equivalents at beginning of the period	651	0
Cash and cash equivalents at end of period	193,210	651	0
Eliminations
Condensed Financial Statements, Captions [Line Items]
Net cash (used in) provided by operating activities	0	0	0
Cash flows from investing activities:
Cash paid in connection with acquisitions, net of cash acquired	0	0
Cash paid to acquire non-marketable securities		0
Loans to subsidiaries	683,063	49,430
Loans to Parent	37,589
Intercompany advances made	1,009,014	290,633	43,931
Repayments from subsidiaries	(87,824)
Investment in subsidiaries	350,000		15,000
Notes receivable to non-guarantor	227,512
Repayments of notes receivable from non-guarantor	(110,000)
Investment in joint ventures	0
Deposits	0	0	0
Capital expenditures	0	0	0
Acquisition of exploration rights	0
Other investing activities	0	0	0
Net cash used in investing activities	2,109,354	340,063	58,931
Cash flows from financing activities:
Capital contributions	0		0
Capital contributions from parent company	(350,000)		(15,000)
Repayments of short-term borrowings—related party		0	0
Net proceeds from sale of common stock in conjunction with initial public offering			0
Repayments of debt	0	0
Net proceeds from sale of preferred stock		0
Net proceeds from sale of common stock	0
Issuance of 10% Senior Secured Notes	0
Issuance of Convertible Notes	0	0
Proceeds from short-term borrowings—related party			0
Payments of preferred dividends	0	0
Dividend paid to noncontrolling interests	0
Proceeds from debt	0	0
Borrowings from parent	(683,063)	(49,430)
Repayments of borrowings to parent	87,824
Borrowing from guarantor	(265,101)
Repayments of borrowings to guarantor	110,000
Intercompany advances owed	(1,009,014)	(290,633)	(43,931)
Other financing activities	0		0
Net cash provided by financing activities	(2,109,354)	(340,063)	(58,931)
Effect of exchange rate changes on cash	0	0
Net change in cash and cash equivalents	0	0	0
Cash and cash equivalents at beginning of the period	0	0	0
Cash and cash equivalents at end of period	$ 0	$ 0	$ 0