Supplemental Oil And Gas Disclosures (Tables)

12 Months Ended

Dec. 31, 2015

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:

	2015			2014			2013
	(In thousands)
Capitalized costs:
Proved properties	$	5,401,618		$	4,990,753		$	4,235,712
Unproved properties	337,099			485,568			545,588
	5,738,717			5,476,321			4,781,300
Accumulated depreciation, depletion, amortization, and impairment	(4,631,404		)	(2,786,678		)	(2,439,458		)
Net capitalized costs	$	1,107,313		$	2,689,643		$	2,341,842
Cost incurred:
Unproved properties acquired	$	41,777		$	76,041		$	76,304
Proved properties acquired	179			5,723			—
Exploration	19,222			68,811			33,373
Development	208,845			615,252			424,314
Asset retirement obligation	(5,693		)	(37,687		)	(17,951		)
Total costs incurred	$	264,330		$	728,140		$	516,040

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, 2015, by the year in which such costs were incurred:

	2015		2014		2013		2012 and Prior		Total
	(In thousands)
Unproved properties acquired and wells in progress	$	49,283	$	65,970	$	44,607	$	177,239	$	337,099

Results Of Operations For Producing Activities [Table Text Block]

The results of operations for producing activities are as follows:

	2015			2014			2013
	(In thousands)
Revenues	$	371,335		$	723,566		$	633,792
Production costs	(152,560		)	(165,315		)	(162,822		)
Depreciation, depletion, amortization, and impairment	(1,844,726		)	(347,220		)	(222,672		)
	(1,625,951		)	211,031			248,298
Income tax (expense) benefit	612,496			(82,028		)	(96,091		)
Results of operations for producing activities (excluding corporate overhead and financing costs)	$	(1,013,455	)	$	129,003		$	152,207

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
	(In thousands)
2013
Proved developed and undeveloped reserves:
Beginning of year	21,998		35,166		555,647
Revision of previous estimates (1)	(2,113	)	836		2,421
Extensions and discoveries	4,678		7,273		68,611
Infill reserves in existing proved fields	2,299		1,945		21,573
Purchases of minerals in place	—		—		11
Production	(3,360	)	(3,914	)	(56,757	)
Sales	(1,737	)	(101	)	(9,722	)
End of year	21,765		41,205		581,784
Proved developed reserves:
Beginning of year	16,441		25,657		452,844
End of year	15,594		30,437		464,234
Proved undeveloped reserves:
Beginning of year	5,557		9,509		102,803
End of year	6,171		10,768		117,550
2014
Proved developed and undeveloped reserves:
Beginning of year	21,765		41,205		581,784
Revision of previous estimates (1)	(3,174	)	(2,266	)	(32,790	)
Extensions and discoveries	5,327		10,850		113,541
Infill reserves in existing proved fields	2,775		3,577		47,189
Purchases of minerals in place	236		88		368
Production	(3,844	)	(4,629	)	(58,854	)
Sales	(418	)	(296	)	(4,277	)
End of year	22,667		48,529		646,961
Proved developed reserves:
Beginning of year	15,594		30,437		464,234
End of year	17,448		35,850		500,950
Proved undeveloped reserves:
Beginning of year	6,171		10,768		117,550
End of year	5,219		12,679		146,011
2015
Proved developed and undeveloped reserves:
Beginning of year	22,667		48,529		646,961
Revision of previous estimates (1)	(3,954	)	(9,367	)	(139,514	)
Extensions and discoveries	1,208		1,948		20,974
Infill reserves in existing proved fields	670		1,861		22,641
Purchases of minerals in place	—		—		—
Production	(3,783	)	(5,274	)	(65,546	)
Sales	(73	)	(10	)	(648	)
End of year	16,735		37,687		484,868
Proved developed reserves:
Beginning of year	17,448		35,850		500,950
End of year	14,679		31,218		416,395
Proved undeveloped reserves:
Beginning of year	5,219		12,679		146,011
End of year	2,056		6,469		68,473

_________________________

(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:

	2015			2014			2013
	(In thousands)
Future cash flows	$	2,475,898		$	6,398,236		$	5,573,119
Future production costs	(1,017,777		)	(2,069,636		)	(1,734,985		)
Future development costs	(228,445		)	(560,102		)	(571,170		)
Future income tax expenses	(230,544		)	(1,228,533		)	(1,044,608		)
Future net cash flows	999,132			2,539,965			2,222,356
10% annual discount for estimated timing of cash flows	(409,646		)	(1,104,221		)	(996,380		)
Standardized measure of discounted future net cash flows relating to proved oil, NGLs, and natural gas reserves	$	589,486		$	1,435,744		$	1,225,976

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:

	2015			2014			2013
	(In thousands)
Sales and transfers of oil and natural gas produced, net of production costs	$	(218,115	)	$	(558,252	)	$	(470,970	)
Net changes in prices and production costs	(1,356,333		)	(33,259		)	188,826
Revisions in quantity estimates and changes in production timing	(213,945		)	(135,125		)	(10,650		)
Extensions, discoveries, and improved recovery, less related costs	95,671			635,752			426,377
Changes in estimated future development costs	227,857			96,339			26,629
Previously estimated cost incurred during the period	59,117			164,430			96,457
Purchases of minerals in place	—			8,395			9
Sales of minerals in place	(3,338		)	(19,135		)	(43,435		)
Accretion of discount	209,979			179,190			147,579
Net change in income taxes	562,838			(98,119		)	(170,091		)
Other—net	(209,989		)	(30,448		)	(44,711		)
Net change	(846,258		)	209,768			146,020
Beginning of year	1,435,744			1,225,976			1,079,956
End of year	$	589,486		$	1,435,744		$	1,225,976