Exploration and Production Activities (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2015

Oil and Gas Exploration and Production Industries Disclosures [Abstract]

Capitalized costs relating to oil and gas producing activities disclosure

The following table sets forth capitalized costs and accumulated depreciation, depletion and amortization related to oil and natural gas producing activities at December 31:

	2015		*	2014		2013
	(In thousands)
Subject to amortization	$	—		$	3,205,036	$	2,893,010
Not subject to amortization	—			132,141		124,869
Total capitalized costs	—			3,337,177		3,017,879
Less accumulated depreciation, depletion and amortization	—			1,752,566		1,562,116
Net capitalized costs	$	—		$	1,584,611	$	1,455,763

* Excludes assets held for sale.

Cost incurred in oil and gas property acquisition, exploration, and development activities disclosure

Capital expenditures, including those not subject to amortization, related to oil and natural gas producing activities were as follows:

Years ended December 31,	2015		*	2014		**	2013		**
	(In thousands)
Acquisitions:
Proved properties	$	—		$	87,919		$	1,817
Unproved properties	—			138,683			4,608
Exploration	—			16,879			26,975
Development	—			331,400			355,421
Total capital expenditures	$	—		$	574,881		$	388,821

* No wells were drilled in 2015.

** Excludes net additions/(reductions) to property, plant and equipment related to the recognition of future liabilities for asset retirement obligations associated with the plugging and abandonment of oil and natural gas wells of $(9.0) million and $(10.7) million for the years ended December 31, 2014 and 2013, respectively.

Results of operations for oil and gas producing activities disclosure

The following reflects the results of operations from the Company's oil and natural gas producing activities included in discontinued operations, excluding corporate overhead and financing costs:

Years ended December 31,	2015			2014		2013
				(In thousands)
Income (loss) from discontinued operations	$	(772,385	)	$	111,998	$	110,191

Schedule of proved developed and undeveloped oil and gas reserve quantities

The changes in the Company's estimated quantities of proved oil, NGL and natural gas reserves for the year ended December 31, 2015, were as follows:

	Oil (MBbls)		NGL (MBbls)		Natural Gas (MMcf)		Total (MBOE)
Proved developed and undeveloped reserves:
Balance at beginning of year	43,918		7,187		245,011		91,940
Production	(3,286	)	(393	)	(16,747	)	(6,471	)
Extensions and discoveries	744		29		681		888
Improved recovery	—		—		—		—
Purchases of proved reserves	—		—		—		—
Sales of proved reserves	(16,474	)	(6,864	)	(202,560	)	(57,097	)
Revisions of previous estimates	(12,215	)	252		(23,854	)	(15,939	)
Balance at end of year	12,687		211		2,531		13,321

Significant changes in proved reserves for the year ended December 31, 2015, include:

• Sales of proved reserves of (57.1) MMBOE, primarily due to the Company's decision to sell Fidelity and exit the exploration and production business

• Revisions of previous estimates of (15.9) MMBOE, largely the result of lower commodity prices

The changes in the Company's estimated quantities of proved oil, NGL and natural gas reserves for the year ended December 31, 2014, were as follows:

	Oil (MBbls)		NGL (MBbls)		Natural Gas (MMcf)		Total (MBOE)
Proved developed and undeveloped reserves:
Balance at beginning of year	41,019		6,602		198,445		80,695
Production	(4,919	)	(609	)	(20,822	)	(8,998	)
Extensions and discoveries	9,654		3,634		64,420		24,025
Improved recovery	—		—		—		—
Purchases of proved reserves	5,463		—		7,711		6,748
Sales of proved reserves	(4,945	)	(3,109	)	(40,451	)	(14,796	)
Revisions of previous estimates	(2,354	)	669		35,708		4,266
Balance at end of year	43,918		7,187		245,011		91,940

Significant changes in proved reserves for the year ended December 31, 2014, include:

• Extensions and discoveries of 24.0 MMBOE, primarily due to drilling activity at the Company's East Texas, Bakken and Powder River Basin properties

• Purchases of proved reserves of 6.7 MMBOE, primarily due to the purchase of working interests and leasehold positions in the Powder River Basin

• Sales of proved reserves of (14.8) MMBOE, primarily at the Company's South Texas and Bakken properties

• Revisions of previous estimates of 4.3 MMBOE, largely the result of higher natural gas prices and well performance revisions

The changes in the Company's estimated quantities of proved oil, NGL and natural gas reserves for the year ended December 31, 2013, were as follows:

	Oil (MBbls)		NGL (MBbls)		Natural Gas (MMcf)		Total (MBOE)
Proved developed and undeveloped reserves:
Balance at beginning of year	33,453		7,153		239,278		80,486
Production	(4,815	)	(781	)	(28,008	)	(10,264	)
Extensions and discoveries	13,313		1,333		26,428		19,050
Improved recovery	—		—		—		—
Purchases of proved reserves	—		—		—		—
Sales of proved reserves	(1,286	)	(25	)	(40,055	)	(7,987	)
Revisions of previous estimates	354		(1,078	)	802		(590	)
Balance at end of year	41,019		6,602		198,445		80,695

Significant changes in proved reserves for the year ended December 31, 2013, include:

• Extensions and discoveries of 19.1 MMBOE, primarily due to drilling activity and new PUD locations at the Company's Bakken and Paradox Basin properties, as well as new PUD locations at Big Horn and East Texas

• Sales of proved reserves of (8.0) MMBOE, primarily at the Company's Green River Basin property

The following table summarizes the breakdown of the Company's proved reserves between proved developed and PUD reserves at December 31:

	2015	2014	2013
Proved developed reserves:
Oil (MBbls)	11,380	30,130	31,394
NGL (MBbls)	144	4,217	5,322
Natural Gas (MMcf)	2,033	184,437	176,546
Total (MBOE)	11,865	65,086	66,140
PUD reserves:
Oil (MBbls)	1,307	13,788	9,625
NGL (MBbls)	67	2,970	1,280
Natural Gas (MMcf)	498	60,574	21,899
Total (MBOE)	1,456	26,854	14,555
Total proved reserves:
Oil (MBbls)	12,687	43,918	41,019
NGL (MBbls)	211	7,187	6,602
Natural Gas (MMcf)	2,531	245,011	198,445
Total (MBOE)	13,321	91,940	80,695

Standardized measure of discounted future cash flows relating to proved reserves disclosure

The standardized measure of the Company's estimated discounted future net cash flows of total proved reserves associated with its various oil and natural gas interests at December 31 was as follows:

	2014		2013
	(In thousands)
Future cash inflows	$	5,185,500	$	4,507,000
Future production costs	1,856,900		1,734,800
Future development costs	570,200		403,000
Future net cash flows before income taxes	2,758,400		2,369,200
Future income tax expense	686,100		545,200
Future net cash flows	2,072,300		1,824,000
10% annual discount for estimated timing of cash flows	997,400		810,000
Discounted future net cash flows relating to proved oil, NGL and natural gas reserves	$	1,074,900	$	1,014,000

Note: Standardized measure not applicable in 2015 as the remaining oil and natural gas properties are held for sale and subject to fair value impairment.

The following are the sources of change in the standardized measure of discounted future net cash flows by year:

	2014			2013
	(In thousands)
Beginning of year	$	1,014,000		$	883,400
Net revenues from production	(368,900		)	(398,000		)
Net change in sales prices and production costs related to future production	86,300			162,200
Extensions and discoveries, net of future production-related costs	231,900			366,500
Improved recovery, net of future production-related costs	—			—
Purchases of proved reserves, net of future production-related costs	103,800			—
Sales of proved reserves	(219,300		)	(37,800		)
Changes in estimated future development costs	65,100			6,700
Development costs incurred during the current year	104,600			141,500
Accretion of discount	109,400			94,600
Net change in income taxes	(33,400		)	(141,400		)
Revisions of previous estimates	(16,300		)	(55,800		)
Other	(2,300		)	(7,900		)
Net change	60,900			130,600
End of year	$	1,074,900		$	1,014,000

Note: Standardized measure not applicable in 2015 as the remaining oil and natural gas properties are held for sale and subject to fair value impairment.