Revenues and Segment Information, Activity (Details) $ in Millions		3 Months Ended								12 Months Ended
		Dec. 31, 2019 USD ($) refinery ethanol_plant	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Sep. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2019 USD ($) refinery ethanol_plant segment		Dec. 31, 2018 USD ($)		Dec. 31, 2017 USD ($)
Segment Information for our Reportable Segments
Revenues		$ 27,879	$ 27,249	$ 28,933	$ 24,263	$ 28,730	$ 30,849	$ 31,015	$ 26,439	$ 108,324	[1]	$ 117,033	[1]	$ 93,980	[1]
Cost of sales:
Cost of materials and other										96,476		104,732		83,037
Operating expenses (excluding depreciation and amortization expense reflected below)										4,868		4,690		4,504
Depreciation and amortization expense										2,202		2,017		1,934
Total cost of sales										103,546		111,439		89,475
Other operating expenses										21		45		61
General and administrative expenses (excluding depreciation and amortization expense reflected below)										868		925		829
Depreciation and amortization expense										53		52		52
Operating income by segment		$ 1,739	$ 881	$ 908	$ 308	$ 1,299	$ 1,219	$ 1,253	$ 801	3,836		4,572		3,563
Total expenditures for long-lived assets	[2]									$ 2,846		3,376		1,948
Segment Information (Textual)
Number of reportable segments | segment										3
Number of petroleum refineries | refinery		15								15
Number of ethanol plants | ethanol_plant		14								14
Corporate, Reconciling Items, and Eliminations[Member]
Segment Information for our Reportable Segments
Revenues										$ (494)		(401)		(420)
Cost of sales:
Operating income by segment										(921)		(974)		(876)
Corporate [Member]
Segment Information for our Reportable Segments
Revenues										2		4		5
Cost of sales:
General and administrative expenses (excluding depreciation and amortization expense reflected below)										868		925		829
Depreciation and amortization expense										53		52		52
Total expenditures for long-lived assets	[2]									58		44		44
Intersegment Eliminations [Member]
Segment Information for our Reportable Segments
Revenues										(496)		(405)		(425)
Cost of sales:
Cost of materials and other										(494)		(404)		(425)
Operating expenses (excluding depreciation and amortization expense reflected below)										0		0		0
Depreciation and amortization expense										0		0		0
Total cost of sales										(494)		(404)		(425)
Other operating expenses										0		0		0
Refining [Member]
Segment Information for our Reportable Segments
Revenues										103,746		113,093		90,258
Refining [Member] | Operating Segments [Member]
Segment Information for our Reportable Segments
Revenues										103,764		113,118		90,266
Cost of sales:
Cost of materials and other										93,371		101,866		80,160
Operating expenses (excluding depreciation and amortization expense reflected below)										4,289		4,154		4,014
Depreciation and amortization expense										2,062		1,910		1,824
Total cost of sales										99,722		107,930		85,998
Other operating expenses										20		45		61
General and administrative expenses (excluding depreciation and amortization expense reflected below)										0		0		0
Depreciation and amortization expense										0		0		0
Operating income by segment										4,022		5,143		4,207
Total expenditures for long-lived assets	[2]									2,581		2,767		1,732
Refining [Member] | Intersegment Eliminations [Member]
Segment Information for our Reportable Segments
Revenues										18		25		8
Ethanol [Member]
Segment Information for our Reportable Segments
Revenues										3,606		3,428		3,324
Ethanol [Member] | Operating Segments [Member]
Segment Information for our Reportable Segments
Revenues										3,837		3,638		3,500
Cost of sales:
Cost of materials and other										3,239		3,008		2,804
Operating expenses (excluding depreciation and amortization expense reflected below)										504		470		443
Depreciation and amortization expense										90		78		81
Total cost of sales										3,833		3,556		3,328
Other operating expenses										1		0		0
General and administrative expenses (excluding depreciation and amortization expense reflected below)										0		0		0
Depreciation and amortization expense										0		0		0
Operating income by segment										3		82		172
Total expenditures for long-lived assets	[2]									47		373		84
Ethanol [Member] | Intersegment Eliminations [Member]
Segment Information for our Reportable Segments
Revenues										231		210		176
Renewable Diesel [Member]
Segment Information for our Reportable Segments
Revenues										970		508		393
Renewable Diesel [Member] | Operating Segments [Member]
Segment Information for our Reportable Segments
Revenues										1,217		678		634
Cost of sales:
Cost of materials and other										360		262		498
Operating expenses (excluding depreciation and amortization expense reflected below)										75		66		47
Depreciation and amortization expense										50		29		29
Total cost of sales										485		357		574
Other operating expenses										0		0		0
General and administrative expenses (excluding depreciation and amortization expense reflected below)										0		0		0
Depreciation and amortization expense										0		0		0
Operating income by segment										732		321		60
Total expenditures for long-lived assets	[2]									160		192		88
Renewable Diesel [Member] | Intersegment Eliminations [Member]
Segment Information for our Reportable Segments
Revenues										$ 247		$ 170		$ 241

[1] Includes excise taxes on sales by certain of our international operations of $5,595 million, $5,626 million, and $5,573 million for the years ended December 31, 2019, 2018, and 2017.

[2] Total expenditures for long-lived assets includes amounts related to capital expenditures; deferred turnaround and catalyst costs; and property, plant, and equipment for acquisitions.