Financial Information Related To Guarantor Subsidaries (Statement Of Operations) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Condensed Financial Statements, Captions [Line Items]
Revenues	$ 1,178,247	$ 1,179,665	$ 1,243,319	$ 966,837	$ 562,400	$ 537,042	$ 479,893	$ 384,997	$ 4,568,068	$ 1,964,332	$ 1,563,043
Cost of services (exclusive of items shown separately below)	722,814	708,608	711,284	546,767	293,596	285,124	250,667	217,022	2,689,473	1,046,409	848,492
Depreciation, depletion, amortization and accretion	143,009	128,160	135,516	102,596	67,264	61,807	60,020	55,824	509,281	244,915	208,097
General and administrative expenses									662,792	376,619	332,602
Income (loss) from operations									706,522	296,389	173,852
Other income (expense):
Other income (expense)									853	(822)	825
Interest income									3,170	6,226	5,135
Interest expense, net									(117,682)	(72,994)	(56,480)
Gains (Losses) on Extinguishment of Debt									(2,294)
Intercompany interest income (expense)
Earnings (losses) from consolidated subsidiaries
Earnings (losses) from equity-method investments, net									(287)	16,394	8,245
Gain loss from Equity method investment									17,880
Income (loss) from continuing operations before income taxes									608,162	245,193	131,577
Income taxes									225,020	85,804	45,431
Net income (loss) from continuing operations									383,142	159,389	86,146
Discontinued operations, net of income tax			(970)	(16,237)	(33,976)	4,781	6,734	5,626	(17,207)	(16,835)	(4,329)
Net income									365,935	142,554	81,817
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									404	683	322
Income (loss) from operations									(404)	(683)	(322)
Other income (expense):
Other income (expense)
Interest income
Interest expense, net
Gains (Losses) on Extinguishment of Debt
Intercompany interest income (expense)
Earnings (losses) from consolidated subsidiaries									566,021	218,198	119,801
Earnings (losses) from equity-method investments, net
Gain loss from Equity method investment
Income (loss) from continuing operations before income taxes									565,617	217,515	119,479
Income taxes									202,152	81,533	39,722
Net income (loss) from continuing operations									363,465	135,982	79,757
Discontinued operations, net of income tax									2,470	6,572	2,060
Net income									365,935	142,554	81,817
Issuer [Member]
Condensed Financial Statements, Captions [Line Items]
Revenues
Cost of services (exclusive of items shown separately below)
Depreciation, depletion, amortization and accretion									685	523	515
General and administrative expenses									144,187	79,672	98,220
Income (loss) from operations									(144,872)	(80,195)	(98,735)
Other income (expense):
Other income (expense)									745	(1,005)	825
Interest income									104	1,097	150
Interest expense, net									(114,927)	(72,414)	(53,716)
Gains (Losses) on Extinguishment of Debt									(2,294)
Intercompany interest income (expense)										26,673	15,883
Earnings (losses) from consolidated subsidiaries									811,768	330,553	255,257
Earnings (losses) from equity-method investments, net									(287)	15,180	985
Gain loss from Equity method investment									17,880
Income (loss) from continuing operations before income taxes									567,995	219,889	120,649
Income taxes
Net income (loss) from continuing operations									567,995	219,889	120,649
Discontinued operations, net of income tax									(1,975)	(1,691)	(848)
Net income									566,020	218,198	119,801
Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Revenues									3,908,584	1,624,945	1,295,946
Cost of services (exclusive of items shown separately below)									2,300,284	817,551	687,519
Depreciation, depletion, amortization and accretion									425,648	200,614	169,528
General and administrative expenses									406,212	230,972	181,234
Income (loss) from operations									776,440	375,808	257,665
Other income (expense):
Other income (expense)									108	183
Interest income									3,036	4,536	4,459
Interest expense, net									(6)	(43)	(216)
Gains (Losses) on Extinguishment of Debt
Intercompany interest income (expense)
Earnings (losses) from consolidated subsidiaries									46,881	2,621	3,555
Earnings (losses) from equity-method investments, net
Gain loss from Equity method investment
Income (loss) from continuing operations before income taxes									826,459	383,105	265,463
Income taxes
Net income (loss) from continuing operations									826,459	383,105	265,463
Discontinued operations, net of income tax									(14,693)	(21,564)	(5,387)
Net income									811,766	361,541	260,076
Non-Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Revenues									817,614	406,843	337,526
Cost of services (exclusive of items shown separately below)									547,145	295,998	231,082
Depreciation, depletion, amortization and accretion									82,948	43,778	38,054
General and administrative expenses									112,163	65,608	53,146
Income (loss) from operations									75,358	1,459	15,244
Other income (expense):
Other income (expense)
Interest income									30	593	526
Interest expense, net									(2,749)	(537)	(2,548)
Gains (Losses) on Extinguishment of Debt
Intercompany interest income (expense)										(26,673)	(15,883)
Earnings (losses) from consolidated subsidiaries
Earnings (losses) from equity-method investments, net										1,214	7,260
Gain loss from Equity method investment
Income (loss) from continuing operations before income taxes									72,761	(23,944)	4,599
Income taxes									22,868	4,271	5,709
Net income (loss) from continuing operations									49,893	(28,215)	(1,110)
Discontinued operations, net of income tax									(3,009)	(152)	(154)
Net income									46,884	(28,367)	(1,264)
Consolidation, Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Revenues									(158,130)	(67,456)	(70,429)
Cost of services (exclusive of items shown separately below)									(157,956)	(67,140)	(70,109)
Depreciation, depletion, amortization and accretion
General and administrative expenses									(174)	(316)	(320)
Income (loss) from operations
Other income (expense):
Other income (expense)
Interest income
Interest expense, net
Gains (Losses) on Extinguishment of Debt
Intercompany interest income (expense)
Earnings (losses) from consolidated subsidiaries									(1,424,670)	(551,372)	(378,613)
Earnings (losses) from equity-method investments, net
Gain loss from Equity method investment
Income (loss) from continuing operations before income taxes									(1,424,670)	(551,372)	(378,613)
Income taxes
Net income (loss) from continuing operations									(1,424,670)	(551,372)	(378,613)
Discontinued operations, net of income tax
Net income									$ (1,424,670)	$ (551,372)	$ (378,613)