Impairment of Natural Gas and Crude Oil Properties (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020
Impairment of natural gas and crude oil properties [Line Items]
Delaware Basin Proved Property Impairment		$ 753.0
Delaware Basin Unproved Property Impairment		127.3
Results of Operations, Impairment of Oil and Gas Properties	$ 0.0	$ 881.1

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