Property, Plant and Equipment

3 Months Ended

Mar. 31, 2016

Property Plant And Equipment [Abstract]

Property, Plant and Equipment

NOTE 4. PROPERTY, PLANT AND EQUIPMENT

Property, plant and equipment includes the following (in thousands):

	March 31, 2016			December 31, 2015
Oil and natural gas properties:
Subject to depletion	$	1,822,014		$	1,627,367
Not subject to depletion
Incurred in 2016		198,231			—
Incurred in 2015		54,130			118,101
Incurred in 2014 and prior		491,663			500,693
Total not subject to depletion		744,024			618,794
Gross oil and natural gas properties		2,566,038			2,246,161
Accumulated depreciation, depletion and impairment		(338,199	)		(290,186	)
Oil and natural gas properties, net		2,227,839			1,955,975
Other property and equipment		40,340			37,253
Less accumulated depreciation		(8,927	)		(7,475	)
Other property and equipment, net		31,413			29,778
Total property, plant, and equipment, net	$	2,259,252		$	1,985,753

Costs subject to depletion are proved costs and costs not subject to depletion are unproved costs and current drilling projects. At March 31, 2016 and December 31, 2015, the Company had excluded $744.0 million and $618.8 million, respectively, of capitalized costs from depletion.

As the Company’s exploration and development work progresses and the reserves on the Company’s properties are proven, capitalized costs attributed to the properties are subject to DD&A. Depletion of capitalized costs is provided using the units-of-production method based on proved oil and gas reserves related to the associated reservoir. Depletion expense on capitalized oil and gas property was $47.9 million and $36.4 million for the three months ended March 31, 2016 and 2015, respectively. The Company had no exploratory wells in progress at March 31, 2016 or December 31, 2015.