Exploration and Production Activities (Unaudited) (Tables)

12 Months Ended

Dec. 31, 2016

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, prior to Fidelity's assets being held for sale, at December 31:

	2014
	(In thousands)
Subject to amortization	$	3,205,036
Not subject to amortization	132,141
Total capitalized costs	3,337,177
Less accumulated depreciation, depletion and amortization	1,752,566
Net capitalized costs	$	1,584,611

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 prior to Fidelity's assets being held for sale, excluding the years ended December 31, 2016 and 2015, due to no wells being drilled during that time, were as follows:

Year ended December 31,	2014		*
	(In thousands)
Acquisitions:
Proved properties	$	87,919
Unproved properties	138,683
Exploration	16,879
Development	331,400
Total capital expenditures	$	574,881

* Excludes net 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 for the year ended December 31, 2014.

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, 2016, were as follows:

	Oil (MBbls)		NGL (MBbls)		Natural Gas (MMcf)		Total (MBOE)
Proved developed and undeveloped reserves:
Balance at beginning of year	12,687		211		2,531		13,321
Production	—		—		—		—
Extensions and discoveries	—		—		—		—
Improved recovery	—		—		—		—
Purchases of proved reserves	—		—		—		—
Sales of proved reserves	(12,687	)	(211	)	(2,531	)	(13,321	)
Revisions of previous estimates	—		—		—		—
Balance at end of year	—		—		—		—

Significant changes in proved reserves for the year ended December 31, 2016, include:

• Sales of proved reserves of (13.3) MMBOE, due to the Company's decision to sell Fidelity and exit the exploration and production business

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

	2016	2015	2014
Proved developed reserves:
Oil (MBbls)	—	11,380	30,130
NGL (MBbls)	—	144	4,217
Natural Gas (MMcf)	—	2,033	184,437
Total (MBOE)	—	11,865	65,086
PUD reserves:
Oil (MBbls)	—	1,307	13,788
NGL (MBbls)	—	67	2,970
Natural Gas (MMcf)	—	498	60,574
Total (MBOE)	—	1,456	26,854
Total proved reserves:
Oil (MBbls)	—	12,687	43,918
NGL (MBbls)	—	211	7,187
Natural Gas (MMcf)	—	2,531	245,011
Total (MBOE)	—	13,321	91,940