CONSOLIDATED STATEMENTS OF OPERATIONS (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Revenues	$ 502,557	$ 381,761
Cost of revenues	273,799	201,252
Selling, general and administrative expenses	44,927	36,057
Depreciation and amortization	51,570	39,537
Loss (gain) on disposition of assets, net	1,404	(1,411)
Operating profit	130,857	106,326
Interest expense	(596)	(1,079)
Interest income	5	4
Other income, net	920	334
Income before income taxes	131,186	105,585
Income tax provision	50,431	40,061
Net income	$ 80,755	$ 65,524
Earnings per share
Basic	$ 0.37	$ 0.30
Diluted	$ 0.37	$ 0.30
Dividends per share	$ 0.08	$ 0.05
Average shares outstanding
Basic	215,620	217,522
Diluted	217,350	220,544