Condensed Consolidated Balance Sheets (USD $) In Thousands	Sep. 30, 2011	Dec. 31, 2010
Current assets:
Cash and cash equivalents	$ 1,160	$ 1,359
Accounts receivable, net of allowance for doubtful accounts of $5,083 at both September 30, 2011 and at December 31, 2010	153,827	130,142
Materials and supplies	8,096	6,316
Current derivative assets (Note 10)	41,257	5,568
Current income tax receivable	11,868	25,211
Current deferred tax asset	10,013	13,537
Prepaid expenses and other	9,749	6,047
Total current assets	235,970	188,180
Property and equipment:
Drilling equipment	1,386,388	1,273,861
Oil and natural gas properties on the full cost method:
Proved properties	3,166,022	2,738,093
Undeveloped leasehold not being amortized	184,540	175,065
Gas gathering and processing equipment	258,854	199,564
Transportation equipment	33,749	31,688
Other	35,607	28,511
Property, plant and equipment, gross, total	5,065,160	4,446,782
Less accumulated depreciation, depletion, amortization and impairment	2,242,812	2,047,031
Net property and equipment	2,822,348	2,399,751
Deferred financing costs, net	5,815	0
Goodwill	62,808	62,808
Other intangible assets, net	2,168	3,022
Non-current derivative assets (Note 10)	23,989	2,537
Other assets	12,153	12,942
Total assets	3,165,251	2,669,240
Current liabilities:
Accounts payable	105,493	89,885
Accrued liabilities (Note 5)	60,588	30,093
Contract advances	1,392	2,582
Current derivative liabilities (Note 10)	552	14,446
Current portion of other long-term liabilities (Note 6)	10,031	10,122
Total current liabilities	178,056	147,128
Long-term debt (Note 6)	305,400	163,000
Non-current derivative liabilities (Note 10)	0	4,359
Other long-term liabilities (Note 6)	112,701	88,030
Deferred income taxes	658,659	556,106
Shareholders' equity:
Preferred stock, $1.00 par value, 5,000,000 shares authorized, none issued	0	0
Common stock, $.20 par value, 175,000,000 shares authorized, 48,150,732 and 47,910,431 shares issued, respectively	9,540	9,493
Capital in excess of par value	404,892	393,501
Accumulated other comprehensive gain (loss)	37,323	(6,851)
Retained earnings	1,458,680	1,314,474
Total shareholders' equity	1,910,435	1,710,617
Total liabilities and shareholders' equity	$ 3,165,251	$ 2,669,240