CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Cash flows from operating activities
Net loss	$ (11,899)	$ (26,340)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation, depletion and amortization	50,817	34,843
Derivative contracts:
Net losses (gains)	305	(1,328)
Cash settlements	7,981	6,744
Deferred income tax benefit	(6,601)	(14,201)
Gain on sales of property and equipment, net	(756)	(480)
Non-cash exploration expense	8,171	26,999
Non-cash interest expense	1,015	3,272
Share-based compensation	1,615	1,796
Other, net	56	236
Changes in operating assets and liabilities, net	19,997	(2,105)
Net cash provided by operating activities	70,701	29,436
Cash flows from investing activities
Capital expenditures - property and equipment	(94,469)	(100,729)
Proceeds from sales of property and equipment, net	778	360
Other, net		100
Net cash used in investing activities	(93,691)	(100,269)
Cash flows from financing activities
Dividends paid	(2,586)	(2,576)
Proceeds from revolving credit facility borrowings	23,000
Repayment of revolving credit facility borrowings	(3,000)
Other, net		838
Net cash provided by (used in) financing activities	17,414	(1,738)
Net decrease in cash and cash equivalents	(5,576)	(72,571)
Cash and cash equivalents - beginning of period	7,512	120,911
Cash and cash equivalents - end of period	1,936	48,340
Cash paid for:
Interest (net of amounts capitalized)	557	387
Income taxes (net of refunds received)	$ (301)	$ (120)