Revenues and Segment Information, Disaggregation of Revenue by Product (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenue by Segment
Revenues	[1]	$ 27,748	$ 10,397	$ 48,554	$ 32,499
Refining [Member]
Revenue by Segment
Revenues		25,968	9,615	45,437	30,600
Refining [Member] | Gasoline and Blendstocks [Member]
Revenue by Segment
Revenues		12,432	3,993	21,161	12,237
Refining [Member] | Distillates [Member]
Revenue by Segment
Revenues		10,875	4,379	19,456	15,042
Refining [Member] | Other Product Revenues [Member]
Revenue by Segment
Revenues		2,661	1,243	4,820	3,321
Renewable Diesel [Member]
Revenue by Segment
Revenues		496	239	848	545
Renewable Diesel [Member] | Renewable Diesel [Member]
Revenue by Segment
Revenues		496	239	848	545
Ethanol [Member]
Revenue by Segment
Revenues		1,284	543	2,269	1,354
Ethanol [Member] | Ethanol [Member]
Revenue by Segment
Revenues		983	432	1,735	1,061
Ethanol [Member] | Distillers Grains [Member]
Revenue by Segment
Revenues		$ 301	$ 111	$ 534	$ 293

[1] Includes excise taxes on sales by certain of our international operations of $1,422 million and $784 million for the three months ended June 30, 2021 and 2020, respectively, and $2,542 million and $2,152 million for the six months ended June 30, 2021 and 2020, respectively.