Segment Information, Activity (Details) $ in Millions	3 Months Ended												12 Months Ended
	Dec. 31, 2017 USD ($)	[1]	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	[2]	Jun. 30, 2016 USD ($)		Mar. 31, 2016 USD ($)		Dec. 31, 2017 USD ($) segment		Dec. 31, 2016 USD ($)		Dec. 31, 2015 USD ($)
Segment Information for our Reportable Segments
Operating revenues	$ 26,392		$ 23,562	$ 22,254	$ 21,772	$ 20,712	$ 19,649		$ 19,584	[3]	$ 15,714	[4]	$ 93,980	[5]	$ 75,659	[5]	$ 87,804	[5]
Cost of materials and other													83,037		65,962		73,861
Operating expenses (excluding depreciation and amortization expense reflected below)													4,462		4,207		4,243
Depreciation and amortization expense													1,934		1,846		1,795
Lower of cost or market inventory valuation adjustment									(454)		(293)		0		(747)		790
Total cost of sales													89,433		71,268		80,689
Other operating expenses													61		0		0
General and administrative expenses (excluding depreciation and amortization expense reflected below)													835		715		710
Depreciation and amortization expense													52		48		47
Asset impairment loss									56				0		56		0
Operating income by segment	$ 853		$ 1,338	$ 871	$ 537	$ 620	$ 892		$ 1,231	[3]	$ 829	[4]	3,599		3,572		6,358
Total expenditures for long-lived assets													$ 1,948		1,996		2,350
Segment Information (Textual)
Number of reportable segments | segment													3
Corporate, Reconciling Items, and Eliminations[Member]
Segment Information for our Reportable Segments
Operating revenues													$ (629)		(573)		(395)
Operating income by segment													(882)		(763)		(757)
Corporate [Member]
Segment Information for our Reportable Segments
Operating revenues													5		0		0
General and administrative expenses (excluding depreciation and amortization expense reflected below)													835		715		710
Depreciation and amortization expense													52		48		47
Asset impairment loss															0
Total expenditures for long-lived assets													44		38		29
Intersegment Eliminations [Member]
Segment Information for our Reportable Segments
Operating revenues													(634)		(573)		(395)
Cost of materials and other													(632)		(573)		(395)
Operating expenses (excluding depreciation and amortization expense reflected below)													(2)		0		0
Depreciation and amortization expense													0		0		0
Total cost of sales													(634)		(573)		(395)
Other operating expenses													0
Refining [Member]
Segment Information for our Reportable Segments
Operating revenues													90,651		71,968		84,521
Refining [Member] | Operating Segments [Member]
Segment Information for our Reportable Segments
Operating revenues													90,657		71,968		84,521
Cost of materials and other													80,865		63,405		71,512
Operating expenses (excluding depreciation and amortization expense reflected below)													3,917		3,696		3,689
Depreciation and amortization expense													1,800		1,734		1,699
Lower of cost or market inventory valuation adjustment															(697)		740
Total cost of sales													86,582		68,138		77,640
Other operating expenses													58
General and administrative expenses (excluding depreciation and amortization expense reflected below)													0		0		0
Depreciation and amortization expense													0		0		0
Asset impairment loss															56
Operating income by segment													4,017		3,774		6,881
Total expenditures for long-lived assets													1,710		1,867		2,216
Refining [Member] | Intersegment Eliminations [Member]
Segment Information for our Reportable Segments
Operating revenues													6		0		0
Ethanol [Member]
Segment Information for our Reportable Segments
Operating revenues													3,324		3,691		3,283
Ethanol [Member] | Operating Segments [Member]
Segment Information for our Reportable Segments
Operating revenues													3,500		3,901		3,434
Cost of materials and other													2,804		3,130		2,744
Operating expenses (excluding depreciation and amortization expense reflected below)													443		415		448
Depreciation and amortization expense													81		66		50
Lower of cost or market inventory valuation adjustment															(50)		50
Total cost of sales													3,328		3,561		3,292
Other operating expenses													0
General and administrative expenses (excluding depreciation and amortization expense reflected below)													0		0		0
Depreciation and amortization expense													0		0		0
Asset impairment loss															0
Operating income by segment													172		340		142
Total expenditures for long-lived assets													84		68		67
Ethanol [Member] | Intersegment Eliminations [Member]
Segment Information for our Reportable Segments
Operating revenues													176		210		151
VLP [Member]
Segment Information for our Reportable Segments
Operating revenues													0		0		0
VLP [Member] | Operating Segments [Member]
Segment Information for our Reportable Segments
Operating revenues													452		363		244
Cost of materials and other													0		0		0
Operating expenses (excluding depreciation and amortization expense reflected below)													104		96		106
Depreciation and amortization expense													53		46		46
Lower of cost or market inventory valuation adjustment															0		0
Total cost of sales													157		142		152
Other operating expenses													3
General and administrative expenses (excluding depreciation and amortization expense reflected below)													0		0		0
Depreciation and amortization expense													0		0		0
Asset impairment loss															0
Operating income by segment													292		221		92
Total expenditures for long-lived assets													110		23		38
VLP [Member] | Intersegment Eliminations [Member]
Segment Information for our Reportable Segments
Operating revenues													$ 452		$ 363		$ 244

[1] During the quarter ended December 31, 2017, we recognized an income tax benefit of $1.9 billion related to Tax Reform as described in Note 14.

[2] During the quarter ended September 30, 2016, we recognized a tax benefit of $42 million related to the Aruba Disposition as described in Note 2.

[3] During the quarter ended June 30, 2016, we recognized a favorable noncash lower of cost or market inventory valuation adjustment of $454 million as described in Note 4 and an asset impairment loss of $56 million related to the Aruba Disposition as described in Note 2.

[4] During the quarter ended March 31, 2016, we recognized a favorable noncash lower of cost or market inventory valuation adjustment of $293 million as described in Note 4.

[5] Includes excise taxes on sales by certain of our international operations of $5,573 million, $5,493 million, and $5,980 million for the years ended December 31, 2017, 2016, and 2015.