Revenues and Segment Information, Disaggregation of Revenue by Product (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Revenue by Segment
Revenues	[1]	$ 26,439	$ 21,772
Corporate, Reconciling Items And Eliminations [Member]
Revenue by Segment
Revenues		(181)	(166)
Corporate [Member]
Revenue by Segment
Revenues		1	0
Other Revenues [Member] | Corporate [Member]
Revenue by Segment
Revenues		1	0
Refining [Member]
Revenue by Segment
Revenues		25,561	20,887
Refining [Member] | Operating Segments [Member]
Revenue by Segment
Revenues		25,565	20,887
Refining [Member] | Gasoline and Blendstocks [Member]
Revenue by Segment
Revenues		10,629	9,335
Refining [Member] | Distillates [Member]
Revenue by Segment
Revenues		12,658	9,696
Refining [Member] | Other Product Revenues [Member]
Revenue by Segment
Revenues		2,274	1,856
Ethanol [Member]
Revenue by Segment
Revenues		877	885
Ethanol [Member] | Operating Segments [Member]
Revenue by Segment
Revenues		923	945
Ethanol [Member] | Ethanol Product [Member]
Revenue by Segment
Revenues		701	750
Ethanol [Member] | Distillers Grains [Member]
Revenue by Segment
Revenues		176	135
VLP [Member]
Revenue by Segment
Revenues		0	0
VLP [Member] | Operating Segments [Member]
Revenue by Segment
Revenues		132	106
VLP [Member] | Eliminations And Reconciling Items [Member]
Revenue by Segment
Revenues		(132)	(106)
VLP [Member] | Pipeline Transportation Services [Member] | Operating Segments [Member]
Revenue by Segment
Revenues		31	23
VLP [Member] | Terminaling Services [Member] | Operating Segments [Member]
Revenue by Segment
Revenues		99	83
VLP [Member] | Storage and Other Services [Member] | Operating Segments [Member]
Revenue by Segment
Revenues		$ 2	$ 0

[1] Includes excise taxes on sales by certain of our international operations of $1,464 million and $1,272 million for the three months ended March 31, 2018 and 2017, respectively.