Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
OPERATING ACTIVITIES:
Net income (loss)	$ 195,867	$ 146,484	$ (55,500)
Adjustments to reconcile net income (loss) to net cash provided (used) by operating activities:
Depreciation, depletion and amortization	280,451	205,124	177,166
Impairment of oil and natural gas properties (Note 2)	0	0	281,241	[1]
Unrealized (gain) loss on derivatives	(2,413)	(1,036)	1,944
(Gain) loss on disposition of assets	595	(9,687)	(6,224)
Deferred tax expense (benefit)	125,551	100,672	(32,003)
Employee stock compensation plans	14,303	10,067	10,708
Bad debt expense	260	0	975
ARO liability accretion	3,838	2,937	2,585
Other, net	294	(69)	(130)
Changes in operating assets and liabilities increasing (decreasing) cash:
Accounts receivable	(38,731)	(58,965)	116,472
Materials and supplies	(1,886)	598	3,009
Prepaid expenses and other	22,672	6,957	(1,525)
Accounts payable	(1,064)	(8,913)	(7,068)
Accrued liabilities	9,245	(3,555)	(1,410)
Contract advances	(527)	(542)	235
Net cash provided by operating activities	608,455	390,072	490,475
INVESTING ACTIVITIES:
Capital expenditures	(728,551)	(484,080)	(316,660)
Producing property and other acquisitions	(50,013)	(92,573)	0
Proceeds from disposition of property and equipment	10,328	40,048	44,733
Acquisition of other assets	0	344	0
Net cash used in investing activities	(768,236)	(536,261)	(271,927)
FINANCING ACTIVITIES:
Borrowings under line of credit	441,500	286,900	95,600
Payments under line of credit	(554,500)	(153,900)	(265,100)
Proceeds from issuance of senior subordinated notes, net of offering costs	243,950	0	0
Proceeds from exercise of stock options	679	149	282
Tax (expense) benefit from stock options	1,174	40	(252)
Increase (decrease) in book overdrafts (Note 2)	26,454	13,219	(48,522)
Net cash provided by (used in) financing activities	159,257	146,408	(217,992)
Net increase (decrease) in cash and cash equivalents	(524)	219	556
Cash and cash equivalents, beginning of year	1,359	1,140	584
Cash and cash equivalents, end of year	835	1,359	1,140
Supplemental disclosure of cash flow information:
Interest paid (net of capitalized)	3,470	0	682
Income taxes	655	3,143	12,302
Changes in accounts payable and accrued liabilities related to purchases of property, plant and equipment	$ (28,036)	$ (29,700)	$ 18,285

[1] In March 2009, we incurred a $281.2 million pre-tax ($175.1 million net of tax) non-cash write down of our oil and natural gas properties due to low commodity prices existing at the end of the first quarter 2009.