CONSOLIDATED BALANCE SHEETS (USD $) In Thousands	Sep. 30, 2011	Dec. 31, 2010
Current assets:
Cash and cash equivalents	$ 10,645	$ 27,612
Accounts receivable, net of allowance for doubtful accounts of $4,885 and $5,114 at September 30, 2011 and December 31, 2010, respectively	472,227	337,167
Federal and state income taxes receivable		75,062
Inventory	25,556	17,215
Deferred tax assets, net	123,828	26,815
Assets held for sale		23,370
Other	59,022	50,169
Total current assets	691,278	557,410
Property and equipment, net	3,025,606	2,620,900
Goodwill and intangible assets	176,601	179,683
Deposits on equipment purchases	80,932	51,084
Other	12,276	13,954
Total assets	3,986,693	3,423,031
Current liabilities:
Accounts payable	267,990	162,400
Federal and state income taxes payable	854
Accrued expenses	152,301	147,315
Current portion of long-term debt	10,000	6,250
Total current liabilities	431,145	315,965
Borrowings under revolving credit facility	15,800
Long-term debt	385,000	392,500
Deferred tax liabilities, net	718,927	511,422
Other	9,088	15,537
Total liabilities	1,559,960	1,235,424
Commitments and contingencies (see Note 11)
Stockholders' equity:
Preferred stock, par value $.01; authorized 1,000,000 shares, no shares issued
Common stock, par value $.01; authorized 300,000,000 shares with 183,108,650 and 181,537,568 issued and 155,625,890 and 154,193,754 outstanding at September 30, 2011 and December 31, 2010, respectively	1,831	1,815
Additional paid-in capital	831,869	796,641
Retained earnings	2,199,560	1,987,999
Accumulated other comprehensive income	18,137	21,597
Treasury stock, at cost, 27,482,760 shares and 27,343,814 shares at September 30, 2011 and December 31, 2010, respectively	(624,664)	(620,445)
Total stockholders' equity	2,426,733	2,187,607
Total liabilities and stockholders' equity	$ 3,986,693	$ 3,423,031