The expense recorded to reduce the value of oil and gas assets consisting of proved properties and unproved properties as the estimate of future successful production from these properties is reduced.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109226691&loc=d3e2921-110230

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
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-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3602-108585

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 360
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-URI http://asc.fasb.org/extlink&oid=66906256&loc=d3e66150-109466

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

Basis of Presentation (Details Textuals 2)	3 Months Ended				6 Months Ended
Basis of Presentation (Details Textuals 2)	Jun. 30, 2021 USD ($)	Mar. 31, 2021 USD ($) $ / Barrel	Jun. 30, 2020 USD ($)	Mar. 31, 2020 USD ($)	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)
Oil and Gas, Average Sale Price and Production Cost Per Unit [Line Items]
Impairment of unevaluated costs				$ 244,900,000
Write-down of oil and natural gas properties	$ 0	$ 14,400,000	$ 662,440,000	$ 72,500,000	$ 14,377,000	$ 734,981,000
Oil
Oil and Gas, Average Sale Price and Production Cost Per Unit [Line Items]
Average price \| $ / Barrel		36.40