Impairments (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2020	Sep. 30, 2021
Proved oil and natural gas properties
Property, Plant and Equipment [Line Items]
Rate used to discount expected future net cash flows		11.00%
Total impairments	$ 8,446
Sand Mine
Property, Plant and Equipment [Line Items]
Total impairments	$ 76

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

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration