CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Per Share data	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Revenues	$ 502,235	$ 302,200	$ 1,327,025	$ 768,240
Cost of revenues	279,936	162,529	724,179	431,621
Selling, general and administrative expenses	37,190	33,095	109,203	90,410
Depreciation and amortization	46,476	33,091	130,906	98,736
Loss (gain) on disposition of assets, net	4,179	(905)	2,690	(1,574)
Operating profit	134,454	74,390	360,047	149,047
Interest expense	(887)	(707)	(2,964)	(1,750)
Interest income	9	14	16	46
Other (expense) income, net	(906)	441	(582)	556
Income before income taxes	132,670	74,138	356,517	147,899
Income tax provision	49,559	27,869	134,717	56,628
Net income	$ 83,111	$ 46,269	$ 221,800	$ 91,271
Earnings per share
Basic	$ 0.57	$ 0.32	$ 1.53	$ 0.63
Diluted	$ 0.57	$ 0.32	$ 1.51	$ 0.62
Dividends per share	$ 0.08	$ 0.04	$ 0.22	$ 0.09
Average shares outstanding
Basic	145,274	145,061	145,168	144,950
Diluted	146,866	146,757	146,955	146,462