Supplemental Oil And Gas Disclosures (Tables)

12 Months Ended

Dec. 31, 2019

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:

	2019		2018		2017
	(In thousands)
Capitalized costs:
Proved properties	$	6,341,582	$	6,018,568	$	5,712,813
Unproved properties	252,874		330,216		296,764
	6,594,456		6,348,784		6,009,577
Accumulated depreciation, depletion, amortization, and impairment	(5,846,177)		(5,124,257)		(4,996,696)
Net capitalized costs	$	748,279	$	1,224,527	$	1,012,881
Cost incurred:
Unproved properties acquired	$	34,668	$	57,430	$	47,029
Proved properties acquired	3,653		15,158		47,638
Exploration	16,480		15,907		14,811
Development	211,443		280,692		160,941
Asset retirement obligation	76		(7,629)		(3,613)
Total costs incurred	$	266,320	$	361,558	$	266,806

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, 2019, by the year in which such costs were incurred:

	2019		2018		2017		2016 and Prior		Total
	(In thousands)
Unproved properties acquired and wells in progress	$	22,621	$	54,780	$	47,646	$	127,827	252,874

Results Of Operations For Producing Activities [Table Text Block]

The results of operations for producing activities are as follows:

	2019		2018		2017
	(In thousands)
Revenues	$	314,925	$	411,601	$	347,285
Production costs	(116,051)		(113,810)		(107,332)
Depreciation, depletion, amortization, and impairment	(727,529)		(132,923)		(96,392)
	(528,655)		164,868		143,561
Income tax (expense) benefit	101,952		(42,915)		(56,376)
Results of operations for producing activities (excluding corporate overhead and financing costs)	$	(426,703)	$	121,953	$	87,185

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)
2017
Proved developed and undeveloped reserves:
Beginning of year	15,696	34,482	405,579	117,774
Revision of previous estimates	730	4,325	38,330	11,444
Extensions and discoveries	2,235	4,520	49,321	14,975
Infill reserves in existing proved fields	1,632	5,779	52,270	16,123
Purchases of minerals in place	2,019	1,197	15,313	5,768
Production	(2,715)	(4,737)	(51,260)	(15,996)
Sales	(84)	(80)	(903)	(314)
End of year	19,513	45,486	508,650	149,774
Proved developed reserves:
Beginning of year	12,724	28,502	347,121	99,079
End of year	14,862	33,358	388,446	112,961
Proved undeveloped reserves:
Beginning of year	2,972	5,980	58,458	18,695
End of year	4,651	12,128	120,204	36,813
2018
Proved developed and undeveloped reserves:
Beginning of year	19,513	45,486	508,650	149,774
Revision of previous estimates (1)	180	(1,368)	(17,859)	(4,165)
Extensions and discoveries	3,250	5,149	75,806	21,033
Infill reserves in existing proved fields	1,898	2,795	23,778	8,656
Purchases of minerals in place	701	856	6,897	2,707
Production	(2,874)	(4,925)	(55,627)	(17,070)
Sales	(110)	(197)	(5,682)	(1,254)
End of year	22,558	47,796	535,963	159,681
Proved developed reserves:
Beginning of year	14,862	33,358	388,446	112,961
End of year	15,192	33,515	377,216	111,576
Proved undeveloped reserves:
Beginning of year	4,651	12,128	120,204	36,813
End of year	7,366	14,281	158,747	48,105
2019
Proved developed and undeveloped reserves:
Beginning of year	22,558	47,796	535,963	159,681
Revision of previous estimates (2)	(8,263)	(20,961)	(234,852)	(68,366)
Extensions and discoveries (2)	703	845	8,798	3,015
Infill reserves in existing proved fields	271	434	4,806	1,506
Purchases of minerals in place	183	101	1,316	503
Production	(3,208)	(4,773)	(53,064)	(16,825)
Sales	(48)	(412)	(42,780)	(7,590)
End of year	12,196	23,030	220,187	71,924
Proved developed reserves:
Beginning of year	15,192	33,515	377,216	111,576
End of year	12,196	23,030	220,187	71,924
Proved undeveloped reserves:
Beginning of year	7,366	14,281	158,747	48,105
End of year	—	—	—	—

_________________________

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

2.Revisions of previous estimates and extensions and discoveries decreased primarily due to the removal of proved undeveloped reserves due to uncertainty regarding our ability to finance the development of our proved undeveloped reserves over a five-year period and from lower commodity 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 adjusted for permanent differences that relate to existing proved oil, NGLs, and natural gas reserves. Future income tax expenses consider the Tax Act statutory tax rates. SMOG as of December 31 is as follows:

	2019		2018		2017
	(In thousands)
Future cash flows	$	1,386,777	$	3,980,369	$	3,347,396
Future production costs	(698,357)		(1,479,744)		(1,308,244)
Future development costs	—		(442,984)		(369,560)
Future income tax expenses	(321)		(307,916)		(234,152)
Future net cash flows	688,099		1,749,725		1,435,440
10% annual discount for estimated timing of cash flows	(226,390)		(766,047)		(628,270)
Standardized measure of discounted future net cash flows relating to proved oil, NGLs, and natural gas reserves	$	461,709	$	983,678	$	807,170

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:

	2019		2018		2017
	(In thousands)
Sales and transfers of oil and natural gas produced, net of production costs	$	(200,233)	$	(297,791)	$	(239,953)
Net changes in prices and production costs	(508,066)		120,062		236,126
Revisions in quantity estimates and changes in production timing	(338,994)		(33,282)		87,239
Extensions, discoveries, and improved recovery, less related costs	53,123		234,172		102,965
Changes in estimated future development costs	311,190		19,535		(5,194)
Previously estimated cost incurred during the period	64,362		63,557		36,044
Purchases of minerals in place	6,416		23,416		51,686
Sales of minerals in place	(25,813)		(5,004)		(1,447)
Accretion of discount	110,571		89,753		57,517
Net change in income taxes	121,708		(31,674)		(33,389)
Changes in timing and other	(116,233)		(6,236)		(2,634)
Net change	(521,969)		176,508		288,960
Beginning of year	983,678		807,170		518,210
End of year	$	461,709	$	983,678	$	807,170