Financial Information Related to Guarantor Subsidaries (Statements of Operations) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Condensed Financial Statements, Captions [Line Items]
Revenues	$ 1,179,665	$ 537,042	$ 3,389,821	$ 1,401,932
Cost of services (exclusive of items shown separately below)	708,608	285,124	1,966,659	752,813
Depreciation, depletion, amortization and accretion	128,160	61,807	366,272	177,651
General and administrative expenses	163,458	93,813	496,998	272,243
Income (loss) from operations	179,439	96,298	559,892	199,225
Other income (expense):
Interest expense, net	(28,118)	(18,894)	(88,101)	(47,309)
Gains (Losses) on Extinguishment of Debt	(2,294)		(2,294)
Intercompany interest income (expense)
Earnings (losses) from consolidated subsidiaries
Earnings (losses) from equity-method investments, net		8,198	(287)	13,724
Gain loss from Equity method investment			17,880
Income (loss) from continuing operations before income taxes	149,027	85,602	487,090	165,640
Income taxes	55,140	30,803	180,223	59,589
Net income (loss) from continuing operations	93,887	54,799	306,867	106,051
Discontinued operations, net of income tax		4,781	(17,207)	17,141
Net income	93,887	59,580	289,660	123,192
Parent [Member]
Condensed Financial Statements, Captions [Line Items]
Revenues
Cost of services (exclusive of items shown separately below)
Depreciation, depletion, amortization and accretion
General and administrative expenses	83	81	311	611
Income (loss) from operations	(83)	(81)	(311)	(611)
Other income (expense):
Interest expense, net
Gains (Losses) on Extinguishment of Debt
Intercompany interest income (expense)
Earnings (losses) from consolidated subsidiaries	146,257	94,682	452,358	190,643
Earnings (losses) from equity-method investments, net
Gain loss from Equity method investment
Income (loss) from continuing operations before income taxes	146,174	94,601	452,047	190,032
Income taxes	52,288	32,268	164,857	57,057
Net income (loss) from continuing operations	93,886	62,333	287,190	132,975
Discontinued operations, net of income tax		(2,753)	2,470	(9,783)
Net income	93,886	59,580	289,660	123,192
Issuer [Member]
Condensed Financial Statements, Captions [Line Items]
Revenues
Cost of services (exclusive of items shown separately below)
Depreciation, depletion, amortization and accretion	158	131	527	388
General and administrative expenses	31,229	17,880	117,485	56,360
Income (loss) from operations	(31,387)	(18,011)	(118,012)	(56,748)
Other income (expense):
Interest expense, net	(28,592)	(20,631)	(88,322)	(50,691)
Gains (Losses) on Extinguishment of Debt	(2,294)		(2,294)
Intercompany interest income (expense)		6,822		19,633
Earnings (losses) from consolidated subsidiaries	208,530	118,768	645,368	267,082
Earnings (losses) from equity-method investments, net		8,198	(287)	12,598
Gain loss from Equity method investment			17,880
Income (loss) from continuing operations before income taxes	146,257	95,146	454,333	191,874
Income taxes
Net income (loss) from continuing operations	146,257	95,146	454,333	191,874
Discontinued operations, net of income tax		(464)	(1,975)	(1,231)
Net income	146,257	94,682	452,358	190,643
Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Revenues	1,003,373	450,186	2,933,132	1,176,163
Cost of services (exclusive of items shown separately below)	597,931	222,930	1,693,002	600,340
Depreciation, depletion, amortization and accretion	103,838	51,634	306,161	145,731
General and administrative expenses	102,073	58,426	302,567	162,817
Income (loss) from operations	199,531	117,196	631,402	267,275
Other income (expense):
Interest expense, net	1,253	1,253	2,446	3,523
Gains (Losses) on Extinguishment of Debt
Intercompany interest income (expense)
Earnings (losses) from consolidated subsidiaries	8,110	881	36,311	2,062
Earnings (losses) from equity-method investments, net
Gain loss from Equity method investment
Income (loss) from continuing operations before income taxes	208,894	119,330	670,159	272,860
Income taxes
Net income (loss) from continuing operations	208,894	119,330	670,159	272,860
Discontinued operations, net of income tax		8,073	(14,693)	28,289
Net income	208,894	127,403	655,466	301,149
Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Revenues	198,277	104,476	562,010	279,475
Cost of services (exclusive of items shown separately below)	132,617	79,716	378,848	205,954
Depreciation, depletion, amortization and accretion	24,164	10,042	59,584	31,532
General and administrative expenses	30,118	17,524	76,765	52,680
Income (loss) from operations	11,378	(2,806)	46,813	(10,691)
Other income (expense):
Interest expense, net	(779)	484	(2,225)	(141)
Gains (Losses) on Extinguishment of Debt
Intercompany interest income (expense)		(6,822)		(19,633)
Earnings (losses) from consolidated subsidiaries
Earnings (losses) from equity-method investments, net				1,126
Gain loss from Equity method investment
Income (loss) from continuing operations before income taxes	10,599	(9,144)	44,588	(29,339)
Income taxes	2,852	(1,465)	15,366	2,532
Net income (loss) from continuing operations	7,747	(7,679)	29,222	(31,871)
Discontinued operations, net of income tax		(75)	(3,009)	(134)
Net income	7,747	(7,754)	26,213	(32,005)
Consolidation, Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Revenues	(21,985)	(17,620)	(105,321)	(53,706)
Cost of services (exclusive of items shown separately below)	(21,940)	(17,522)	(105,191)	(53,481)
Depreciation, depletion, amortization and accretion
General and administrative expenses	(45)	(98)	(130)	(225)
Income (loss) from operations
Other income (expense):
Interest expense, net
Gains (Losses) on Extinguishment of Debt
Intercompany interest income (expense)
Earnings (losses) from consolidated subsidiaries	(362,897)	(214,331)	(1,134,037)	(459,787)
Earnings (losses) from equity-method investments, net
Gain loss from Equity method investment
Income (loss) from continuing operations before income taxes	(362,897)	(214,331)	(1,134,037)	(459,787)
Income taxes
Net income (loss) from continuing operations	(362,897)	(214,331)	(1,134,037)	(459,787)
Discontinued operations, net of income tax
Net income	$ (362,897)	$ (214,331)	$ (1,134,037)	$ (459,787)