CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Cash flows from operating activities
Net loss	$ (50,148)	$ (104,976)
Adjustments to reconcile net loss to net cash provided by operating activities:
Non-cash portion of loss on extinguishment of debt	3,144	22,456
Loss on long-term purchase commitment	17,332	0
Depreciation, depletion and amortization	151,888	113,224
Impairments	29,316	71,071
Derivative contracts:
Net gains	(31,250)	(19,827)
Cash settlements	24,189	20,302
Deferred income tax benefit	(32,444)	(60,372)
Gain on sales of property and equipment, net	(2,407)	(223)
Non-cash exploration expense	24,765	52,457
Non-cash interest expense	3,107	5,812
Share-based compensation (equity-classified)	4,233	5,629
Other, net	302	225
Changes in operating assets and liabilities, net	48,187	(2,614)
Net cash provided by operating activities	190,214	103,164
Cash flows from investing activities
Capital expenditures - property and equipment	(257,194)	(318,274)
Proceeds from sales of property and equipment, net	93,276	31,077
Other, net	180	100
Net cash used in investing activities	(163,738)	(287,097)
Cash flows from financing activities
Dividends paid	(5,176)	(7,736)
Proceeds from revolving credit facility borrowings	181,000	30,000
Repayment of revolving credit facility borrowings	(203,000)	(15,000)
Proceeds From Issuance Of Senior Notes	0	300,000
Repurchase of Convertible Notes	0	(232,963)
Debt issuance costs paid	(1,779)	(8,850)
Other, net	0	1,148
Net cash provided by financing activities	(28,955)	66,599
Net increase (decrease) in cash and cash equivalents	(2,479)	(117,334)
Cash and cash equivalents - beginning of period	7,512	120,911
Cash and cash equivalents - end of period	5,033	3,577
Cash paid for:
Interest (net of amounts capitalized)	27,865	17,288
Income taxes (net of refunds received)	$ (32,574)	$ 433