Sales and Other Operating Revenues - Practical Expedients (Details)	9 Months Ended
Sep. 30, 2021
Revenue, Practical Expedient [Abstract]
Revenue, Practical Expedient, Remaining Performance Obligation, Description	We have long-term commodity sales contracts which use prevailing market prices at the time of delivery, and under these contracts, the market-based variable consideration for each performance obligation (i.e., delivery of commodity) is allocated to each wholly unsatisfied performance obligation within the contract.
Practical Expedient	true

Indicates (true false) whether practical expedient was elected not to disclose amount of transaction price allocated to remaining performance obligation and explanation of expected timing of revenue recognition for reporting period presented prior to date of initial application under retrospective method.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 65
-Paragraph 1
-Subparagraph (f)(3)
-URI http://asc.fasb.org/extlink&oid=123338486&loc=SL49131195-203048

Name:	us-gaap_RevenuePracticalExpedientInitialApplicationAndTransitionNondisclosureOfTransactionPriceAllocationToRemainingPerformanceObligation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:booleanItemType
Balance Type:	na
Period Type:	duration