Revenues and Segment Information, Activity (Details) $ in Millions		3 Months Ended			9 Months Ended
		Sep. 30, 2026 USD ($)	Sep. 30, 2025 USD ($)	Mar. 31, 2025 USD ($)	Sep. 30, 2026 USD ($) segment	Sep. 30, 2025 USD ($)	Dec. 31, 2025 USD ($)
Segment Information for our Reportable Segments
Revenues	[1]	$ 46,098	$ 32,168		$ 122,955	$ 92,315
Cost of sales:
Cost of materials and other		32,741	26,132		94,056	76,858
Taxes other than income taxes		1,654	1,826		5,023	4,980
Operating expenses (excluding depreciation and amortization expense reflected below)		1,627	1,614		4,728	4,659
Depreciation and amortization expense		669	824		2,220	2,290
Total cost of sales		36,691	30,396		106,027	88,787
Asset impairment loss		0	0		0	1,131
Other operating expenses		11	5		61	13
Operating income		9,073	1,509		16,000	1,606
Other income, net		127	86		375	292
Interest and debt expense, net of capitalized interest		144	139		429	417
Income before income tax expense		9,056	1,456		15,946	1,481
Segment assets		67,951			67,951		$ 57,988
Expenditures for long-lived assets		432	409		$ 1,230	1,475
Segment Information (Textual)
Number of reportable segments | segment					3
Intersegment Eliminations [Member]
Segment Information for our Reportable Segments
Revenues		(2,084)	(744)		$ (4,910)	(2,110)
Cost of sales:
Operating income		8	2		(53)	29
Segment assets		(546)			(546)		(266)
Operating Segments [Member]
Segment Information for our Reportable Segments
Revenues		48,182	32,912		127,865	94,425
Cost of sales:
Operating income		9,407	1,765		16,947	2,355
Segment assets		56,682	52,105		56,682	52,105	51,316
Expenditures for long-lived assets		426	385		1,206	1,419
Corporate [Member]
Cost of sales:
Other corporate expenses		(342)	(258)		(894)	(778)
Other income, net		127	86		375	292
Interest and debt expense, net of capitalized interest		(144)	(139)		(429)	(417)
Segment assets		11,815			11,815		6,938
Expenditures for long-lived assets		6	24		24	56
Refining [Member]
Segment Information for our Reportable Segments
Revenues		44,369	30,414		117,474	87,495
Segment Information (Textual)
Investments in nonconsolidated joint ventures		675			675		$ 684
Refining [Member] | Intersegment Eliminations [Member]
Segment Information for our Reportable Segments
Revenues		(3)	(1)		(7)	(5)
Refining [Member] | Operating Segments [Member]
Segment Information for our Reportable Segments
Revenues		44,372	30,415		117,481	87,500
Cost of sales:
Cost of materials and other		31,988	24,858		91,434	73,015
Taxes other than income taxes		1,654	1,826		5,023	4,980
Operating expenses (excluding depreciation and amortization expense reflected below)		1,376	1,388		3,985	3,986
Depreciation and amortization expense		580	728		1,947	2,029
Total cost of sales		35,598	28,800		102,389	84,010
Asset impairment loss				$ 1,100		1,131
Other operating expenses		(8)	5		34	13
Operating income		8,782	1,610		15,058	2,346
Segment assets		49,538	45,010		49,538	45,010
Expenditures for long-lived assets		397	324		1,119	1,231
Renewable Diesel [Member]
Segment Information for our Reportable Segments
Revenues		664	719		2,551	1,777
Renewable Diesel [Member] | Intersegment Eliminations [Member]
Segment Information for our Reportable Segments
Revenues		(1,729)	(484)		(3,938)	(1,424)
Renewable Diesel [Member] | Operating Segments [Member]
Segment Information for our Reportable Segments
Revenues		2,393	1,203		6,489	3,201
Cost of sales:
Cost of materials and other		1,883	1,077		4,798	3,016
Taxes other than income taxes		0	0		0	0
Operating expenses (excluding depreciation and amortization expense reflected below)		86	78		262	228
Depreciation and amortization expense		71	76		220	205
Total cost of sales		2,040	1,231		5,280	3,449
Asset impairment loss						0
Other operating expenses		0	0		0	0
Operating income		353	(28)		1,209	(248)
Segment assets		5,669	5,600		5,669	5,600
Expenditures for long-lived assets		4	49		44	158
Segment Information (Textual)
Clean fuel production credit		150	206		505	397
Ethanol [Member]
Segment Information for our Reportable Segments
Revenues		1,065	1,035		2,930	3,043
Ethanol [Member] | Intersegment Eliminations [Member]
Segment Information for our Reportable Segments
Revenues		(352)	(259)		(965)	(681)
Ethanol [Member] | Operating Segments [Member]
Segment Information for our Reportable Segments
Revenues		1,417	1,294		3,895	3,724
Cost of sales:
Cost of materials and other		962	942		2,678	2,962
Taxes other than income taxes		0	0		0	0
Operating expenses (excluding depreciation and amortization expense reflected below)		165	148		481	446
Depreciation and amortization expense		18	21		56	59
Total cost of sales		1,145	1,111		3,215	3,467
Asset impairment loss						0
Other operating expenses		0	0		0	0
Operating income		272	183		680	257
Segment assets		1,475	1,495		1,475	1,495
Expenditures for long-lived assets		25	$ 12		43	$ 30
Segment Information (Textual)
Clean fuel production credit		$ 92			$ 211

[1] Includes excise taxes on sales by certain of our foreign operations of $1,658 million and $1,827 million for the three months ended September 30, 2026 and 2025, respectively, and $5,043 million and $4,993 million for the nine months ended September 30, 2026 and 2025, respectively.