Business Segments - Narrative (Details) - Sales Revenue - Customer Concentration Risk	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Chevron
Segment Reporting Information [Line Items]
Concentration risk	30.00%	24.00%	25.00%
Phillips 66 and Affiliated Companies
Segment Reporting Information [Line Items]
Concentration risk		18.00%	17.00%

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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