Revenues and Segment Information, Disaggregation of Revenue by Product (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Revenue by Segment
Revenues	[1]	$ 24,263	$ 26,439
Corporate, Reconciling Items And Eliminations [Member]
Revenue by Segment
Revenues		(105)	(91)
Corporate [Member]
Revenue by Segment
Revenues		0	1
Corporate - Other Revenues [Member] | Corporate [Member]
Revenue by Segment
Revenues		0	1
Refining [Member]
Revenue by Segment
Revenues		23,218	25,453
Refining [Member] | Operating Segments [Member]
Revenue by Segment
Revenues		23,220	25,457
Refining [Member] | Gasoline and Blendstocks [Member]
Revenue by Segment
Revenues		9,374	10,629
Refining [Member] | Distillates [Member]
Revenue by Segment
Revenues		11,917	12,550
Refining [Member] | Other Product Revenues [Member]
Revenue by Segment
Revenues		1,927	2,274
Ethanol [Member]
Revenue by Segment
Revenues		793	877
Ethanol [Member] | Operating Segments [Member]
Revenue by Segment
Revenues		845	923
Ethanol [Member] | Ethanol [Member]
Revenue by Segment
Revenues		620	701
Ethanol [Member] | Distillers Grains [Member]
Revenue by Segment
Revenues		173	176
Renewable Diesel [Member]
Revenue by Segment
Revenues		252	108
Renewable Diesel [Member] | Operating Segments [Member]
Revenue by Segment
Revenues		303	150
Renewable Diesel [Member] | Renewable Diesel [Member]
Revenue by Segment
Revenues		$ 252	$ 108

[1] Includes excise taxes on sales by certain of our international operations of $1,330 million and $1,464 million for the three months ended March 31, 2019 and 2018, respectively.