Unevaluated Property (Tables)

12 Months Ended

Dec. 31, 2019

Property, Plant and Equipment [Abstract]

Summary of unevaluated properties excluded from oil and natural gas properties being amortized

A summary of the unevaluated property costs excluded from oil and natural gas properties being amortized at December 31, 2019, and the year in which the costs were incurred follows:

	December 31, 2019
	Costs Incurred During:
In thousands	2019		2018		2017		2016 and Prior		Total
Property acquisition costs	$	—	$	—	$	8,527	$	572,930	$	581,457
Exploration and development	3,522		1,862		3,175		108,268		116,827
Capitalized interest	31,489		27,013		23,134		92,990		174,626
Total	$	35,011	$	28,875	$	34,836	$	774,188	$	872,910