Revenues and Segment Information, Assets (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Total Assets by Reportable Segment
Reportable segment assets	$ 47,747	$ 53,864
Corporate and Eliminations [Member]
Total Assets by Reportable Segment
Reportable segment assets	3,036	3,770
Refining [Member] \| Operating Segments [Member]
Total Assets by Reportable Segment
Reportable segment assets	41,465	47,067
Renewable Diesel [Member] \| Operating Segments [Member]
Total Assets by Reportable Segment
Reportable segment assets	1,632	1,412
Ethanol [Member] \| Operating Segments [Member]
Total Assets by Reportable Segment
Reportable segment assets	$ 1,614	$ 1,615

Sum of the carrying amounts as of the balance sheet date of all assets that are recognized. Assets are probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(11))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(12))
-URI http://asc.fasb.org/extlink&oid=119400593&loc=d3e572229-122910

Name:	us-gaap_Assets
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant