Property and Equipment (Tables)

12 Months Ended

Dec. 31, 2016

Property, Plant and Equipment [Abstract]

Summary of the Company's property and equipment

The following table presents a summary of the Company’s property and equipment balances as of December 31, 2016 and 2015 (in thousands).

	December 31,
	2016			2015
Oil and natural gas properties
Evaluated (subject to amortization)	$	2,408,305		$	2,122,174
Unproved and unevaluated (not subject to amortization)	479,736			387,504
Total oil and natural gas properties	2,888,041			2,509,678
Accumulated depletion	(1,850,882		)	(1,574,040		)
Net oil and natural gas properties	1,037,159			935,638
Other property and equipment
Midstream equipment and facilities	145,662			78,564
Furniture, fixtures and other equipment	5,487			2,918
Software	3,206			2,193
Land	1,437			1,539
Leasehold improvements	5,003			1,173
Total other property and equipment	160,795			86,387
Accumulated depreciation	(13,429		)	(9,619		)
Net other property and equipment	147,366			76,768
Net property and equipment	$	1,184,525		$	1,012,406

Breakdown of the Company's unproved and unevaluated property costs not subject to amortization

The following table provides a breakdown of the Company’s unproved and unevaluated property costs not subject to amortization as of December 31, 2016 and the year in which these costs were incurred (in thousands).

Description	2016		2015		2014		2013 and prior		Total
Costs incurred for
Property acquisition	$	126,857	$	236,507	$	55,258	$	23,654	$	442,276
Exploration wells	19,017		3,375		34		—		22,426
Development wells	13,086		1,218		730		—		15,034
Total	$	158,960	$	241,100	$	56,022	$	23,654	$	479,736