Supplemental Oil And Gas Disclosures (Tables)

12 Months Ended

Dec. 31, 2012

Supplemental Oil and Gas Disclosures [Abstract]

Schedule Of Capitalized Costs And Costs Incurred On Oil And Gas Properties

The capitalized costs at year-end and costs incurred during the year were as follows:

	2012			2011			2010
	(In thousands)
Capitalized costs:
Proved properties	$	3,822,381		$	3,302,032		$	2,738,093
Unproved properties	521,659			185,632			175,065
	4,344,040			3,487,664			2,913,158
Accumulated depreciation, depletion, amortization, and impairment	(2,216,787		)	(1,724,312		)	(1,542,352		)
Net capitalized costs	$	2,127,253		$	1,763,352		$	1,370,806
Cost incurred:
Unproved properties acquired	$	420,467		$	70,999		$	75,739
Proved properties acquired	225,669			50,013			50,000
Exploration	46,467			43,836			48,304
Development	390,649			391,862			279,903
Asset retirement obligation	45,097			23,345			9,924
Total costs incurred	$	1,128,349		$	580,055		$	463,870

Schedule Of The Oil And Natural Gas Property Costs Not Being Amortized

The following table shows a summary of the oil and natural gas property costs not being amortized at December 31, 2012, by the year in which such costs were incurred:

	2012		2011		2010		2009 and Prior		Total
	(In thousands)
Undeveloped leasehold acquired and wells in progress	$	428,375	$	62,750	$	19,975	$	10,559	$	521,659

Results Of Operations For Producing Activities

The results of operations for producing activities are as follows:

	2012			2011			2010
	(In thousands)
Revenues	$	557,003		$	505,450		$	392,229
Production costs	(131,389		)	(115,400		)	(91,143		)
Depreciation, depletion, amortization, and impairment	(492,475		)	(181,960		)	(117,793		)
	(66,861		)	208,090			183,293
Income tax (expense) benefit	27,533			(80,323		)	(70,110		)
Results of operations for producing activities (excluding corporate overhead and financing costs)	$	(39,328	)	$	127,767		$	113,183

Schedule Of Proved Developed And Undeveloped Oil And Gas Reserve Quantities

Estimated quantities of proved developed oil, NGLs, and natural gas reserves and changes in net quantities of proved developed and undeveloped oil, NGLs, and natural gas reserves were as follows:

	Oil Bbls		Liquids Bbls		Natural Gas Mcf
	(In thousands)
2012:
Proved Developed and Undeveloped Reserves:
Beginning of Year	20,255		22,087		442,135
Revision of Previous Estimates (1)	(1,747	)	(2,682	)	(55,110	)
Extensions and Discoveries	5,014		4,819		54,761
Infill Reserves in Existing Proved Fields	4,196		3,018		25,057
Purchases of Minerals in Place	2,830		11,098		141,494
Production	(3,279	)	(2,796	)	(48,930	)
Sales	(5,271	)	(378	)	(3,760	)
End of Year	21,998		35,166		555,647
Proved Developed Reserves:
Beginning of Year	15,618		16,649		372,311
End of Year	16,441		25,657		452,844
Proved Undeveloped Reserves:
Beginning of Year	4,637		5,438		69,824
End of Year	5,557		9,509		102,803
2011:
Proved Developed and Undeveloped Reserves:
Beginning of Year	17,494		16,117		420,486
Revision of Previous Estimates (1)	374		2,112		(30,510	)
Extensions and Discoveries	3,477		3,924		39,836
Infill Reserves in Existing Proved Fields	1,229		1,780		15,592
Purchases of Minerals in Place	192		393		40,835
Production	(2,511	)	(2,239	)	(44,104	)
Sales	—		—		—
End of Year	20,255		22,087		442,135
Proved Developed Reserves:
Beginning of Year	12,773		12,088		346,928
End of Year	15,618		16,649		372,311
Proved Undeveloped Reserves:
Beginning of Year	4,721		4,029		73,558
End of Year	4,637		5,438		69,824
2010:
Proved Developed and Undeveloped Reserves:
Beginning of Year	11,669		14,653		419,061
Revision of Previous Estimates (1)	434		(1,559	)	(25,007	)
Extensions and Discoveries	3,473		878		31,328
Infill Reserves in Existing Proved Fields	2,152		3,482		34,128
Purchases of Minerals in Place	1,293		212		1,732
Production	(1,521	)	(1,549	)	(40,756	)
Sales	(6	)	—		—
End of Year	17,494		16,117		420,486
Proved Developed Reserves:
Beginning of Year	9,183		11,538		338,217
End of Year	12,773		12,088		346,928
Proved Undeveloped Reserves:
Beginning of Year	2,486		3,115		80,844
End of Year	4,721		4,029		73,558

_________________________

(1) Natural gas revisions of previous estimates decreased primarily due to a decline in natural gas prices.

Standardized Measure Of Discounted Future Cash Flows Relating To Proved Reserves Disclosure

The standardized measure of discounted future net cash flows (SMOG) was calculated using 12-month average prices and year-end costs and statutory tax rates, adjusted for permanent differences that relate to existing proved oil, NGLs, and natural gas reserves. SMOG as of December 31 is as follows:

	2012			2011			2010
	(In thousands)
Future cash flows	$	4,522,351		$	4,583,629		$	3,745,046
Future production costs	(1,405,773		)	(1,277,856		)	(1,054,630		)
Future development costs	(431,673		)	(340,992		)	(303,152		)
Future income tax expenses	(762,519		)	(952,736		)	(799,260		)
Future net cash flows	1,922,386			2,012,045			1,588,004
10% annual discount for estimated timing of cash flows	(842,430		)	(924,136		)	(732,918		)
Standardized measure of discounted future net cash flows relating to proved oil, NGLs, and natural gas reserves	$	1,079,956		$	1,087,909		$	855,086

Schedule Of Principal Sources Of Changes In Standardized Measure Of Discounted Future Net Cash Flows

The principal sources of changes in the standardized measure of discounted future net cash flows were as follows:

	2012			2011			2010
	(In thousands)
Sales and transfers of oil and natural gas produced, net of production costs	$	(425,626	)	$	(389,339	)	$	(301,086	)
Net changes in prices and production costs	(321,099		)	115,852			379,097
Revisions in quantity estimates and changes in production timing	(148,648		)	(38,336		)	(67,116		)
Extensions, discoveries and improved recovery, less related costs	432,058			401,134			340,771
Changes in estimated future development costs	51,587			37,742			15,974
Previously estimated cost incurred during the period	104,377			45,327			45,327
Purchases of minerals in place	283,774			58,567			42,280
Sales of minerals in place	(112,359		)	(29		)	(120		)
Accretion of discount	157,842			128,492			77,536
Net change in income taxes	94,678			(60,675		)	(200,815		)
Other—net	(124,537		)	(65,912		)	(23,097		)
Net change	(7,953		)	232,823			308,751
Beginning of year	1,087,909			855,086			546,335
End of year	$	1,079,956		$	1,087,909		$	855,086