Revenues and Segment Information, Components of Operating Income (Loss) (Details) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($) segment	Jun. 30, 2020 USD ($)
Segment Information for our Reportable Segments
Revenues	[1]	$ 27,748	$ 10,397	$ 48,554	$ 32,499
Cost of sales:
Cost of materials and other		25,249	9,079	44,241	29,031
LCM inventory valuation adjustment		0	(2,248)	0	294
Operating expenses (excluding depreciation and amortization expense reflected below)		1,214	1,027	2,870	2,151
Depreciation and amortization expense		576	566	1,142	1,135
Total cost of sales		27,039	8,424	48,253	32,611
Other operating expenses		12	3	50	5
General and administrative expenses (excluding depreciation and amortization expense reflected below)		176	169	384	346
Depreciation and amortization expense		12	12	24	25
Operating income (loss)		509	1,789	$ (157)	(488)
Disclosure of Entity's Reportable Segments (Textual)
Number of reportable segments | segment				3
Corporate, Reconciling Items And Eliminations [Member]
Segment Information for our Reportable Segments
Revenues		(161)	(97)	$ (303)	(216)
Cost of sales:
Operating income (loss)		(187)	(182)	(408)	(373)
Corporate [Member]
Segment Information for our Reportable Segments
Revenues		0	0	0	0
Cost of sales:
General and administrative expenses (excluding depreciation and amortization expense reflected below)		176	169	384	346
Depreciation and amortization expense		12	12	24	25
Intersegment Eliminations [Member]
Segment Information for our Reportable Segments
Revenues		(161)	(97)	(303)	(216)
Cost of sales:
Cost of materials and other		(162)	(96)	(303)	(214)
LCM inventory valuation adjustment			0		0
Operating expenses (excluding depreciation and amortization expense reflected below)		0	0	0	0
Depreciation and amortization expense		0	0	0	0
Total cost of sales		(162)	(96)	(303)	(214)
Other operating expenses		0	0	0	0
Refining [Member]
Segment Information for our Reportable Segments
Revenues		25,968	9,615	45,437	30,600
Refining [Member] | Operating Segments [Member]
Segment Information for our Reportable Segments
Revenues		25,969	9,617	45,441	30,604
Cost of sales:
Cost of materials and other		24,000	8,539	42,022	27,666
LCM inventory valuation adjustment			(2,137)		277
Operating expenses (excluding depreciation and amortization expense reflected below)		1,064	928	2,535	1,923
Depreciation and amortization expense		544	533	1,077	1,069
Total cost of sales		25,608	7,863	45,634	30,935
Other operating expenses		12	3	50	5
General and administrative expenses (excluding depreciation and amortization expense reflected below)		0	0	0	0
Depreciation and amortization expense		0	0	0	0
Operating income (loss)		349	1,751	(243)	(336)
Refining [Member] | Intersegment Eliminations [Member]
Segment Information for our Reportable Segments
Revenues		1	2	4	4
Renewable Diesel [Member]
Segment Information for our Reportable Segments
Revenues		496	239	848	545
Renewable Diesel [Member] | Operating Segments [Member]
Segment Information for our Reportable Segments
Revenues		572	296	1,003	655
Cost of sales:
Cost of materials and other		281	135	468	265
LCM inventory valuation adjustment			0		0
Operating expenses (excluding depreciation and amortization expense reflected below)		31	20	60	40
Depreciation and amortization expense		12	12	24	23
Total cost of sales		324	167	552	328
Other operating expenses		0	0	0	0
General and administrative expenses (excluding depreciation and amortization expense reflected below)		0	0	0	0
Depreciation and amortization expense		0	0	0	0
Operating income (loss)		248	129	451	327
Renewable Diesel [Member] | Intersegment Eliminations [Member]
Segment Information for our Reportable Segments
Revenues		76	57	155	110
Ethanol [Member]
Segment Information for our Reportable Segments
Revenues		1,284	543	2,269	1,354
Ethanol [Member] | Operating Segments [Member]
Segment Information for our Reportable Segments
Revenues		1,368	581	2,413	1,456
Cost of sales:
Cost of materials and other		1,130	501	2,054	1,314
LCM inventory valuation adjustment			(111)		17
Operating expenses (excluding depreciation and amortization expense reflected below)		119	79	275	188
Depreciation and amortization expense		20	21	41	43
Total cost of sales		1,269	490	2,370	1,562
Other operating expenses		0	0	0	0
General and administrative expenses (excluding depreciation and amortization expense reflected below)		0	0	0	0
Depreciation and amortization expense		0	0	0	0
Operating income (loss)		99	91	43	(106)
Ethanol [Member] | Intersegment Eliminations [Member]
Segment Information for our Reportable Segments
Revenues		$ 84	$ 38	$ 144	$ 102

[1] Includes excise taxes on sales by certain of our international operations of $1,422 million and $784 million for the three months ended June 30, 2021 and 2020, respectively, and $2,542 million and $2,152 million for the six months ended June 30, 2021 and 2020, respectively.