Condensed Consolidated Balance Sheets (USD $) In Thousands	Jun. 30, 2011	Dec. 31, 2010
Current assets:
Cash and cash equivalents	$ 244,114	$ 50,727
Short Term Investments	164,161	0
Accounts receivable, net of allowance for doubtful accounts of $23,984 and $22,618 at June 30, 2011and December 31, 2010, respectively	437,954	452,450
Prepaid expenses	38,862	25,828
Inventory and other current assets	220,410	235,047
Total current assets	1,105,501	764,052
Property, plant and equipment, net of accumulated depreciation and depletion of $861,737 and $771,602 at June 30, 2011 and December 31, 2010, respectively	1,394,918	1,313,150
Goodwill	589,761	588,000
Notes receivable	71,261	69,026
Equity-method investments	63,308	59,322
Intangible and other long-term assets, net of accumulated amortization of $26,228 and $22,065 at June 30, 2011 and December 31, 2010, respectively	136,888	113,983
Total assets	3,361,637	2,907,533
Current liabilities:
Accounts payable	109,167	110,276
Accrued expenses	170,383	162,044
Income taxes payable	8,955	2,475
Deferred income taxes	24,027	29,353
Current portion of decommissioning liabilities	17,172	16,929
Current maturities of long-term debt	391,262	184,810
Total current liabilities	720,966	505,887
Deferred income taxes	228,191	223,936
Decommissioning liabilities	103,880	100,787
Long-term debt, net	810,184	681,635
Other long-term liabilities	121,800	114,737
Stockholders' equity:
Preferred stock of $.01 par value. Authorized, 5,000,000 shares; none issued	0	0
Common stock of $.001 par value. Authorized, 125,000,000 shares; issued and outstanding 79,822,534 shares at June 30, 2011 and 78,951,053 shares at December 31, 2010	80	79
Additional paid in capital	439,164	415,278
Accumulated other comprehensive loss, net	(17,134)	(25,700)
Retained earnings	954,506	890,894
Total stockholders' equity	1,376,616	1,280,551
Total liabilities and stockholders' equity	$ 3,361,637	$ 2,907,533