Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (loss) from continuing operations	$ 51,177	$ 32,534	$ 11,725
Adjustments to reconcile net income from continuing operations to net cash provided by operating activities-continuing operations-
Depreciation, depletion and amortization	165,621	84,606	47,030
Unrealized (gain) loss on derivative instruments, net	9,751	(12,971)	(14,564)
Accretion related to asset retirement obligations	372	235	216
Loss on extinguishment of debt	0	897	31,023
Stock-based compensation, net of amounts capitalized	11,689	11,864	16,608
Allowance for doubtful accounts	(337)	31	485
Deferred income taxes	30,142	24,546	2,449
Amortization of debt discount and deferred financing costs, net of amounts capitalized	4,584	3,061	7,716
Other, net	4,175	3,105	3,097
Changes in operating assets and liabilities-
Accounts receivable	(67,120)	(23,910)	(10,040)
Accounts payable	26,942	33,457	913
Accrued liabilities	21,832	9,354	(69)
Other, net	(5,757)	(11,298)	(2,173)
Net cash provided by operating activities - continuing operations	253,071	155,511	94,416
Net cash used in operating activities - discontinued operations	(845)	(1,173)	0
Net cash provided by operating activities	252,226	154,338	94,416
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures - oil and gas properties	(735,711)	(516,004)	(340,784)
Capital expenditures - other property and equipment	(4,176)	(1,363)	(843)
Increase (decrease) in capital expenditure payables and accruals	(9,880)	49,346	22,540
Proceeds from sales of oil and gas properties, net	341,597	167,265	54,217
Advances to operators	(3,687)	390	53
Advances for joint operations	(46,110)	50,772	1,668
Other, net	(7,184)	(474)	(966)
Net cash used in investing activities - continuing operations	(465,151)	(250,068)	(264,115)
Net cash used in investing activities - discontinued operations	(42,265)	(35,930)	(6,181)
Net cash used in investing activities	(507,416)	(285,998)	(270,296)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from borrowings and issuances	1,040,772	879,061	910,127
Debt repayments	(796,000)	(752,660)	(917,148)
Payments of debt issuance and retirement costs	(7,101)	(9,622)	(12,213)
Proceeds from common stock offerings, net of offering costs	0	0	188,534
Proceeds from stock options exercised	107	47	690
Net cash provided by financing activities - continuing operations	237,778	116,826	169,990
Net cash provided by financing activities - discontinued operations	41,914	38,818	6,181
Net cash provided by financing activities	279,692	155,644	176,171
NET INCREASE IN CASH AND CASH EQUIVALENTS FROM CONTINUING OPERATIONS	25,698	22,269	291
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS FROM DISCONTINUED OPERATIONS	(1,196)	1,715	0
CASH AND CASH EQUIVALENTS, beginning of year - continuing operations	26,397	4,128	3,837
CASH AND CASH EQUIVALENTS, end of year - continuing operations	52,095	26,397	4,128
CASH AND CASH EQUIVALENTS, beginning of year - discontinued operations	1,715	0	0
CASH AND CASH EQUIVALENTS, end of year - discontinued operations	519	1,715	0
SUPPLEMENTAL CASH FLOW DISCLOSURES
Cash paid for interest, net of amounts capitalized	43,629	26,077	24,218
Cash paid for income taxes	$ 587	$ 4,156	$ 95