Property and Equipment

12 Months Ended

Dec. 31, 2018

Property, Plant and Equipment [Abstract]

Property and Equipment

Property and Equipment

The following table summarizes our property and equipment as of the dates presented: 

	December 31,
	2018			2017
Oil and gas properties:
Proved	$	1,037,993		$	460,029
Unproved	63,484			117,634
Total oil and gas properties	1,101,477			577,663
Other property and equipment	20,383			12,712
Total property and equipment	1,121,860			590,375
Accumulated depreciation, depletion and amortization	(193,866		)	(61,316		)
	$	927,994		$	529,059

Unproved property costs of $63.5 million and $117.6 million have been excluded from amortization as of December 31, 2018 and December 31, 2017, respectively. We transferred $82.8 million and $40.4 million of undeveloped leasehold costs, including capitalized interest, associated with proved undeveloped reserves, acreage unlikely to be drilled or expiring acreage, from unproved properties to the full cost pool during the years ended December 31, 2018 and 2017, respectively. We capitalized internal costs of $3.7 million and $2.4 million and interest of $9.1 million and $2.7 million during the year ended December 31, 2018 and 2017, respectively, in accordance with our accounting policies. Average DD&A per barrel of oil equivalent of proved oil and gas properties was $16.11 and $12.87 for the years ended December 31, 2018 and 2017, $11.21 for the Successor period from September 13, 2016 through December 31, 2016, and $10.04 for the Predecessor period from January 1, 2016 through September 12, 2016. The DD&A rate for the Predecessor period was determined under the successful efforts method while the Successor periods subsequent to September 12, 2016 were determined under the full cost method (see Note 2).