Costs related to the impairment of oil and gas properties.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 932
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-10.(c)(3)(ii)(A)(1))
-URI http://asc.fasb.org/extlink&oid=120398226&loc=d3e511914-122862

Name:	us-gaap_ResultsOfOperationsImpairmentOfOilAndGasProperties
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Property, Plant, and Equipment - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Property, Plant and Equipment [Line Items]
Impairment of Exploration and Production Properties	$ 0	$ 0	$ 61,849	$ 0
Southwest Pennsylvania CBM Asset Group
Property, Plant and Equipment [Line Items]
Impairment of Exploration and Production Properties			$ 61,849