Supplemental Oil And Gas Disclosures (Tables)

12 Months Ended

Dec. 31, 2016

Supplemental Oil and Gas Disclosures [Abstract]

Capitalized Costs Relating to Oil and Gas Producing Activities Disclosure [Table Text Block]

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

	2016			2015			2014
	(In thousands)
Capitalized costs:
Proved properties	$	5,446,305		$	5,401,618		$	4,990,753
Unproved properties	314,867			337,099			485,568
	5,761,172			5,738,717			5,476,321
Accumulated depreciation, depletion, amortization, and impairment	(4,900,304		)	(4,631,404		)	(2,786,678		)
Net capitalized costs	$	860,868		$	1,107,313		$	2,689,643
Cost incurred:
Unproved properties acquired	$	21,675		$	41,777		$	76,041
Proved properties acquired	564			179			5,723
Exploration	17,325			19,222			68,811
Development	80,582			208,845			615,252
Asset retirement obligation	(30,906		)	(5,693		)	(37,687		)
Total costs incurred	$	89,240		$	264,330		$	728,140

Schedule Of The Oil And Natural Gas Property Costs Not Being Amortized [Table Text Block]

The following table shows a summary of the oil and natural gas property costs not being amortized at December 31, 2016, by the year in which such costs were incurred:

	2016		2015		2014		2013 and Prior		Total
	(In thousands)
Unproved properties acquired and wells in progress	$	23,494	$	41,445	$	55,562	$	194,366	$	314,867

Results Of Operations For Producing Activities [Table Text Block]

The results of operations for producing activities are as follows:

	2016			2015			2014
	(In thousands)
Revenues	$	282,742		$	371,335		$	723,566
Production costs	(108,822		)	(152,560		)	(165,315		)
Depreciation, depletion, amortization, and impairment	(268,901		)	(1,844,726		)	(347,220		)
	(94,981		)	(1,625,951		)	211,031
Income tax (expense) benefit	32,696			612,496			(82,028		)
Results of operations for producing activities (excluding corporate overhead and financing costs)	$	(62,285	)	$	(1,013,455	)	$	129,003

Schedule Of Proved Developed And Undeveloped Oil And Gas Reserve Quantities [Table Text Block]

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		NGLs Bbls		Natural Gas Mcf		Total MBoe
	(In thousands)
2014
Proved developed and undeveloped reserves:
Beginning of year	21,765		41,205		581,784		159,934
Revision of previous estimates (1)	(3,174	)	(2,266	)	(32,790	)	(10,905	)
Extensions and discoveries	5,327		10,850		113,541		35,101
Infill reserves in existing proved fields	2,775		3,577		47,189		14,217
Purchases of minerals in place	236		88		368		385
Production	(3,844	)	(4,629	)	(58,854	)	(18,282	)
Sales	(418	)	(296	)	(4,277	)	(1,427	)
End of year	22,667		48,529		646,961		179,023
Proved developed reserves:
Beginning of year	15,594		30,437		464,234		123,403
End of year	17,448		35,850		500,950		136,790
Proved undeveloped reserves:
Beginning of year	6,171		10,768		117,550		36,531
End of year	5,219		12,679		146,011		42,233
2015
Proved developed and undeveloped reserves:
Beginning of year	22,667		48,529		646,961		179,023
Revision of previous estimates (1)	(3,954	)	(9,367	)	(139,514	)	(36,573	)
Extensions and discoveries	1,208		1,948		20,974		6,651
Infill reserves in existing proved fields	670		1,861		22,641		6,304
Purchases of minerals in place	—		—		—		—
Production	(3,783	)	(5,274	)	(65,546	)	(19,981	)
Sales	(73	)	(10	)	(648	)	(191	)
End of year	16,735		37,687		484,868		135,233
Proved developed reserves:
Beginning of year	17,448		35,850		500,950		136,790
End of year	14,679		31,218		416,395		115,296
Proved undeveloped reserves:
Beginning of year	5,219		12,679		146,011		42,233
End of year	2,056		6,469		68,473		19,937
2016
Proved developed and undeveloped reserves:
Beginning of year	16,735		37,687		484,868		135,233
Revision of previous estimates (1)	(549	)	(2,473	)	(31,670	)	(8,300	)
Extensions and discoveries	1,816		1,588		13,720		5,690
Infill reserves in existing proved fields	663		2,724		24,704		7,504
Purchases of minerals in place	114		43		630		262
Production	(2,974	)	(5,014	)	(55,735	)	(17,277	)
Sales	(109	)	(73	)	(30,938	)	(5,338	)
End of year	15,696		34,482		405,579		117,774
Proved developed reserves:
Beginning of year	14,679		31,218		416,395		115,296
End of year	12,724		28,502		347,121		99,079
Proved undeveloped reserves:
Beginning of year	2,056		6,469		68,473		19,937
End of year	2,972		5,980		58,458		18,695

_________________________

(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 [Table Text Block]

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:

	2016			2015			2014
	(In thousands)
Future cash flows	$	2,030,925		$	2,475,898		$	6,398,236
Future production costs	(861,625		)	(1,017,777		)	(2,069,636		)
Future development costs	(173,446		)	(228,445		)	(560,102		)
Future income tax expenses	(141,752		)	(230,544		)	(1,228,533		)
Future net cash flows	854,102			999,132			2,539,965
10% annual discount for estimated timing of cash flows	(335,892		)	(409,646		)	(1,104,221		)
Standardized measure of discounted future net cash flows relating to proved oil, NGLs, and natural gas reserves	$	518,210		$	589,486		$	1,435,744

Schedule Of Principal Sources Of Changes In Standardized Measure Of Discounted Future Net Cash Flows [Table Text Block]

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

	2016			2015			2014
	(In thousands)
Sales and transfers of oil and natural gas produced, net of production costs	$	(173,920	)	$	(218,115	)	$	(558,252	)
Net changes in prices and production costs	(94,026		)	(1,356,333		)	(33,259		)
Revisions in quantity estimates and changes in production timing	(51,979		)	(213,945		)	(135,125		)
Extensions, discoveries, and improved recovery, less related costs	84,738			95,671			635,752
Changes in estimated future development costs	70,976			227,857			96,339
Previously estimated cost incurred during the period	16,602			59,117			164,430
Purchases of minerals in place	2,652			—			8,395
Sales of minerals in place	(17,248		)	(3,338		)	(19,135		)
Accretion of discount	69,069			209,979			179,190
Net change in income taxes	44,241			562,838			(98,119		)
Other—net	(22,381		)	(209,989		)	(30,448		)
Net change	(71,276		)	(846,258		)	209,768
Beginning of year	589,486			1,435,744			1,225,976
End of year	$	518,210		$	589,486		$	1,435,744