Financial Information Related to Guarantor Subsidaries (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Financial Information Related to Subsidiaries
Revenues	$ 966,837	$ 384,997
Cost of services (exclusive of items shown separately below)	546,767	217,022
Depreciation, depletion, amortization and accretion	102,596	55,824
General and administrative expenses	176,021	84,615
Income (loss) from operations	141,453	27,536
Other income (expense):
Interest expense, net	(29,806)	(12,152)
Earnings (Losses) from equity-method investments, net	(287)	27
Income (loss) from continuing operations before income taxes	111,360	15,411
Income taxes	41,203	5,534
Net income (loss) from continuing operations	70,157	9,877
Discontinued operations, net of income tax	(16,237)	5,626
Net income (loss)	53,920	15,503
Parent [Member]
Financial Information Related to Subsidiaries
General and administrative expenses	96	325
Income (loss) from operations	(96)	(325)
Other income (expense):
Earnings (losses) from consolidated subsidiaries	87,637	23,427
Income (loss) from continuing operations before income taxes	87,541	23,102
Income taxes	35,547	4,387
Net income (loss) from continuing operations	51,954	18,715
Discontinued operations, net of income tax	1,926	(3,212)
Net income (loss)	53,920	15,503
Issuer [Member]
Financial Information Related to Subsidiaries
Depreciation, depletion, amortization and accretion	191	128
General and administrative expenses	59,978	18,553
Income (loss) from operations	(60,169)	(18,681)
Other income (expense):
Interest expense, net	(30,483)	(12,561)
Intercompany interest income (expense)		6,206
Earnings (losses) from consolidated subsidiaries	180,551	49,706
Earnings (Losses) from equity-method investments, net	(287)	(878)
Income (loss) from continuing operations before income taxes	89,612	23,792
Net income (loss) from continuing operations	89,612	23,792
Discontinued operations, net of income tax	(1,975)	(365)
Net income (loss)	87,637	23,427
Guarantor Subsidiaries [Member]
Financial Information Related to Subsidiaries
Revenues	835,172	322,655
Cost of services (exclusive of items shown separately below)	466,413	176,845
Depreciation, depletion, amortization and accretion	85,940	45,425
General and administrative expenses	93,209	50,270
Income (loss) from operations	189,610	50,115
Other income (expense):
Interest expense, net	1,339	1,080
Earnings (losses) from consolidated subsidiaries	12,411	634
Income (loss) from continuing operations before income taxes	203,360	51,829
Net income (loss) from continuing operations	203,360	51,829
Discontinued operations, net of income tax	(13,179)	9,249
Net income (loss)	190,181	61,078
Non-Guarantor Subsidiaries [Member]
Financial Information Related to Subsidiaries
Revenues	175,052	77,701
Cost of services (exclusive of items shown separately below)	123,699	55,472
Depreciation, depletion, amortization and accretion	16,465	10,271
General and administrative expenses	22,780	15,531
Income (loss) from operations	12,108	(3,573)
Other income (expense):
Interest expense, net	(662)	(671)
Intercompany interest income (expense)		(6,206)
Earnings (Losses) from equity-method investments, net		905
Income (loss) from continuing operations before income taxes	11,446	(9,545)
Income taxes	5,656	1,147
Net income (loss) from continuing operations	5,790	(10,692)
Discontinued operations, net of income tax	(3,009)	(46)
Net income (loss)	2,781	(10,738)
Eliminations [Member]
Financial Information Related to Subsidiaries
Revenues	(43,387)	(15,359)
Cost of services (exclusive of items shown separately below)	(43,345)	(15,295)
General and administrative expenses	(42)	(64)
Other income (expense):
Earnings (losses) from consolidated subsidiaries	(280,599)	(73,767)
Income (loss) from continuing operations before income taxes	(280,599)	(73,767)
Net income (loss) from continuing operations	(280,599)	(73,767)
Net income (loss)	$ (280,599)	$ (73,767)