Properties and Equipment Properties and Equipment (Tables)

12 Months Ended

Dec. 31, 2019

Capitalized Costs of Unproved Properties Excluded from Amortization [Line Items]

Schedule of Capitalized Costs of Unproved Properties Excluded from Amortization [Table Text Block]

The following table presents the capitalized exploratory well cost pending determination of proved reserves and included in properties and equipment:

	As of December 31,
	2019			2018
	(in thousands, except for number of wells)
Beginning balance	$	12,188		$	15,448
Additions to capitalized exploratory well costs pending the determination of proved reserves	31,901			35,127
Reclassifications to proved properties	(28,011		)	(38,387		)
Ending balance	$	16,078		$	12,188
Number of wells pending determination at period-end	4			2

Property, Plant and Equipment [Table Text Block]

The following table presents the components of properties and equipment, net of accumulated DD&A:

	As of December 31,
	2019			2018
	(in thousands)
Properties and equipment, net:
Crude oil and natural gas properties
Proved	$	6,241,780		$	5,452,613
Unproved	403,379			492,594
Total crude oil and natural gas properties	6,645,159			5,945,207
Infrastructure and other	41,888			60,612
Land and buildings	12,312			11,243
Construction in progress	408,428			356,095
Properties and equipment, at cost	7,107,787			6,373,157
Accumulated DD&A	(3,012,585		)	(2,370,295		)
Properties and equipment, net	$	4,095,202		$	4,002,862

Impairment of natural gas and crude oil properties [Table Text Block]

he following table presents impairment charges recorded for properties and equipment:

	Year Ended December 31,
	2019		2018		2017
	(in thousands)
Impairment of proved and unproved properties	$	10,599	$	458,397	$	285,465
Amortization of individually insignificant unproved properties	—		—		422
Impairment of infrastructure and other	27,937		—		—
Total impairment of properties and equipment	$	38,536	$	458,397	$	285,887