Consolidated Statements Of Cash Flows (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Net Income	$ 63,151	$ 37,927
Net income from discontinued operations, net of income taxes	(24,790)	(1,568)
Adjustments to reconcile net income from continuing operations to net cash provided by operating activities-
Depreciation, depletion and amortization	95,998	74,941
Unrealized (gain) loss on derivative instruments, net	(3,166)	(20,598)
Accretion related to asset retirement obligations	227	194
Stock-based compensation, net of amounts capitalized	9,466	5,532
Allowance for doubtful accounts	7	41
Deferred income taxes	23,994	21,564
Amortization of debt discount and deferred financing costs, net of amounts capitalized	2,386	2,091
Other, net	244	1,793
Changes in operating assets and liabilities-
Accounts receivable	(4,938)	(31,279)
Accounts payable	73,771	50,896
Accrued liabilities	(19,035)	6,366
Other, net	(3,593)	(2,592)
Net cash provided by operating activities - continuing operations	213,722	145,308
Net cash used in operating activities - discontinued operations	(80)	(209)
Net cash provided by operating activities	213,642	145,099
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures - oil and gas properties	(409,928)	(385,611)
Capital expenditures - other property and equipment	(1,196)	(3,388)
Increase in capital expenditure payables and accruals	37,346	619
Proceeds from sales of U.S. oil and gas properties, net	10,681	190,892
Advances to operators	282	(431)
Advances for joint operations	10,345	(33,342)
Other, net	403	(2,655)
Net cash used in investing activities - continuing operations	(352,067)	(233,916)
Net cash provided by (used in) investing activities - discontinued operations	128,179	(19,824)
Net cash used in investing activities	(223,888)	(253,740)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from borrowings and issuances	165,000	520,412
Debt repayments	(206,325)	(438,000)
Payments of costs associated with revolving credit facility and debt issuance	(962)	(239)
Proceeds from stock options exercised	766	6
Net cash provided by (used in) financing activities - continuing operations	(41,521)	82,179
Net cash provided by financing activities - discontinued operations	3,000	19,119
Net cash provided by (used in) financing activities	(38,521)	101,298
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(48,767)	(7,343)
CASH AND CASH EQUIVALENTS, beginning of period	52,614	28,112
CASH AND CASH EQUIVALENTS, end of period	$ 3,847	$ 20,769