CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
REVENUES	$ 1,809,807	$ 1,096,384	$ 587,863
COSTS AND EXPENSES:
Cost of revenues	992,704	606,098	393,806
Selling, general and administrative expenses	151,286	121,839	97,672
Depreciation and amortization	179,905	133,360	130,580
Loss (gain) on disposition of assets, net	3,831	(3,758)	(1,143)
Operating profit (loss)	482,081	238,845	(33,052)
Interest expense	(3,453)	(2,662)	(2,176)
Interest income	18	46	147
Other income, net	169	1,303	1,582
Income (loss) before income taxes	478,815	237,532	(33,499)
Income tax provision (benefit)	182,434	90,790	(10,754)
Net income (loss)	$ 296,381	$ 146,742	$ (22,745)
EARNINGS (LOSS) PER SHARE
Basic	$ 2.04	$ 1.01	$ (0.16)
Diluted	$ 2.02	$ 1.00	$ (0.16)
Dividends paid per share	$ 0.320	$ 0.141	$ 0.148