Properties and Equipment, Net

12 Months Ended

Dec. 31, 2015

Property, Plant and Equipment [Abstract]

Properties and Equipment, Net

Properties and Equipment, Net

Properties and equipment, net are comprised of the following:

	December 31,
(In thousands)	2015			2014
Proved oil and gas properties	$	8,821,146		$	7,984,979
Unproved oil and gas properties	390,434			492,208
Gathering and pipeline systems	243,672			241,272
Land, building and other equipment	117,848			109,758
	9,573,100			8,828,217
Accumulated depreciation, depletion and amortization	(4,596,221		)	(3,902,506		)
	$	4,976,879		$	4,925,711

Impairment

In December 2015, the Company recorded an impairment of $114.9 million associated with oil and gas properties in certain non-core fields in south Texas, east Texas and Louisiana. The impairment of these fields was due to a significant decline in commodity prices in late 2015. These fields were reduced to fair value of approximately $89.9 million using discounted future cash flows.

In December 2014, the Company recorded a $771.0 million impairment of oil and gas properties in certain non-core fields, primarily in east Texas. The impairment of these fields was due to a significant decline in commodity prices in late 2014 and management's decision not to pursue any further activity in these non-core areas in the current price environment. These fields were reduced to fair value of approximately $86.5 million using discounted future cash flows.

The fair value of the impaired fields was based on significant inputs that were not observable in the market and are considered to be Level 3 inputs as defined by ASC 820. Refer to Note 1 for a description of fair value hierarchy. Key assumptions included (i) reserves, including risk adjustments for probable and possible reserves; (ii) production rates based on the Company's experience with similar properties in which it operates; (iii) estimated future operating and development costs; (iv) future commodity prices; (v) future cash flows; and (vi) a market-based weighted average cost of capital rate of 10% at December 31, 2015 and 2014, respectively.

Capitalized Exploratory Well Costs

The following table reflects the net changes in capitalized exploratory well costs:

	Year Ended December 31,
(In thousands)	2015			2014		2013
Balance at beginning of period	$	10,557		$	—	$	10,390
Additions to capitalized exploratory well costs pending the determination of proved reserves	—			10,557		—
Reclassifications to wells, facilities, and equipment based on the determination of proved reserves	(10,557		)	—		(10,198		)
Capitalized exploratory well costs charged to expense	—			—		(192		)
Balance at end of period	$	—		$	10,557	$	—

The following table provides an aging of capitalized exploratory well costs based on the date the drilling was completed:

	December 31,
(In thousands)	2015		2014		2013
Capitalized exploratory well costs that have been capitalized for a period of one year or less	$	—	$	10,557	$	—
Capitalized exploratory well costs that have been capitalized for a period greater than one year	—		—		—
	$	—	$	10,557	$	—