Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2011	Dec. 31, 2010
Current assets:
Cash and cash equivalents	$ 79,086	$ 80,274	$ 210,181	$ 50,727
Accounts receivable, net of allowance for doubtful accounts of $17,392 and $17,484 at June 30, 2012 and December 31, 2011, respectively	1,129,714	540,602
Deferred Tax Assets, Net, Current	31,306
Income tax receivable
Prepaid expenses	102,206	34,037
Inventory and other current assets	180,197	228,309
Available-for-sale Securities, Equity Securities, Current	20,321
Total current assets	1,542,830	883,222
Property, plant and equipment, net of accumulated depreciation and depletion of $984,221 and $970,137 at June 30, 2012 and December 31, 2011, respectively	3,163,273	1,507,368
Goodwill	2,528,312	581,379
Notes receivable	44,129	73,568
Investments in Subsidiaries
Equity-method investments		72,472
Intangible and other long-term assets, net of accumulated amortization of $26,174 and $20,123 at June 30, 2012 and December 31, 2011, respectively	511,074	930,136
Total assets	7,789,618	4,048,145
Current liabilities:
Accounts payable	268,812	178,645
Accrued expenses	360,647	197,574
Income taxes payable	148,857	717
Deferred income taxes		831
Current portion of decommissioning liabilities		14,956	17,090
Current maturities of long-term debt	20,000	810
Total current liabilities	798,316	393,533
Deferred income taxes	727,034	297,458
Decommissioning liabilities	91,012	108,220	105,372
Long-term debt, net	1,909,416	1,685,087
Intercompany Payables or Receivables
Other long-term liabilities	114,771	110,248
Stockholders' equity:
Preferred stock of $0.01 par value. Authorized, 5,000,000 shares; none issued
Common stock of $0.001 par value. Authorized - 250,000,000, Issued - 156,920,904, Outstanding - 157,516,128 at June 30, 2012 Authorized - 125,000,000, Issued and Outstanding, 82,425,443 at December 31, 2011	157	80
Additional paid in capital	2,846,236	447,007
Accumulated other comprehensive loss, net	(20,432)	(26,936)
Retained earnings	1,323,108	1,033,448
Total stockholders' equity	4,149,069	1,453,599
Total liabilities and stockholders' equity	$ 7,789,618	$ 4,048,145