Condensed Consolidated Statements Of Cash Flows (USD $) In Thousands	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010
OPERATING ACTIVITIES:
Net income	$ 144,206	$ 102,819
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, depletion and amortization	201,924	142,930
Unrealized gain on derivatives	(3,611)	(1,202)
Deferred tax expense	94,224	66,177
(Gain) loss on disposition of assets	462	(9,579)
Stock compensation plans	10,780	6,603
Other	2,740	2,113
Changes in operating assets and liabilities increasing (decreasing) cash:
Accounts receivable	(26,118)	(35,863)
Accounts payable	(30,439)	(7,924)
Material and supplies inventory	(1,780)	346
Accrued liabilities	13,487	5,121
Contract advances	(1,190)	720
Other - net	13,166	11,635
Net cash provided by operating activities	417,851	283,896
INVESTING ACTIVITIES:
Capital expenditures	(541,044)	(335,821)
Producing property and other acquisitions	(50,525)	(92,642)
Proceeds from disposition of assets	7,779	34,335
Other - net	0	324
Net cash used in investing activities	(583,790)	(393,804)
FINANCING ACTIVITIES:
Borrowings under line of credit	334,100	205,000
Payments under line of credit	(441,700)	(100,000)
Proceeds from issuance of senior subordinated notes, net of offering costs	243,950	0
Proceeds from exercise of stock options	644	122
Book overdrafts	28,746	4,779
Net cash provided by financing activities	165,740	109,901
Net decrease in cash and cash equivalents	(199)	(7)
Cash and cash equivalents, beginning of period	1,359	1,140
Cash and cash equivalents, end of period	$ 1,160	$ 1,133