Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (loss)	$ 37,927	$ 8,477
Adjustments to reconcile net income to net cash provided by operating activities-
Depreciation, depletion and amortization	74,941	37,271
Unrealized (gain) loss on derivative instruments, net	(20,265)	3,032
Accretion related to asset retirement obligations	348	145
Loss on extinguishment of debt	0	897
Stock-based compensation, net of amounts capitalized	5,532	10,655
Allowance for (recoveries of) doubtful accounts	41	(54)
Deferred income taxes	18,828	4,739
Amortization of debt discount and deferred financing costs, net of amounts capitalized	2,091	1,570
Other, net	2,387	4,058
Changes in operating assets and liabilities-
Accounts receivable	(31,279)	(2,912)
Accounts payable	50,896	8,381
Accrued liabilities	6,244	3,876
Other, net	(2,592)	(6,013)
Net cash provided by operating activities	145,099	74,122
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(409,027)	(219,179)
Increase in capital expenditure payables and accruals	823	12,464
Proceeds from sales of oil and gas properties, net	190,892	101,590
Advances to operators	(431)	(138)
Advances for joint operations	(33,342)	12,368
Other, net	(2,655)	(221)
Net cash used in investing activities	(253,740)	(93,116)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from borrowings and issuances	539,540	346,000
Debt repayments	(438,000)	(298,660)
Payments of debt issuance and retirement costs	(248)	(8,419)
Proceeds from stock options exercised	6	47
Net cash provided by financing activities	101,298	38,968
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(7,343)	19,974
CASH AND CASH EQUIVALENTS, beginning of period	28,112	4,128
CASH AND CASH EQUIVALENTS, end of period	$ 20,769	$ 24,102