Segment Information (Reconciliation of Segment Revenues To Sales and Other Operating Revenues) (Detail) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Segment Reporting Information [Line Items]
Sales and other operating revenues	[1]	$ 37,914	$ 36,343	$ 70,620	$ 71,207
Refining & Marketing
Segment Reporting Information [Line Items]
Sales and other operating revenues	[1]	36,654	35,167	68,139	68,830
Midstream
Segment Reporting Information [Line Items]
Sales and other operating revenues	[1]	1,260	1,176	2,481	2,377
Operating Segments
Segment Reporting Information [Line Items]
Sales and other operating revenues		39,396	37,711	73,542	73,964
Operating Segments | Refining & Marketing
Segment Reporting Information [Line Items]
Sales and other operating revenues		36,688	35,188	68,210	68,878
Operating Segments | Midstream
Segment Reporting Information [Line Items]
Sales and other operating revenues		2,708	2,523	5,332	5,086
Intersegment Eliminations
Segment Reporting Information [Line Items]
Sales and other operating revenues		1,482	1,368	2,922	2,757
Intersegment Eliminations | Refining & Marketing
Segment Reporting Information [Line Items]
Sales and other operating revenues		34	21	71	48
Intersegment Eliminations | Midstream
Segment Reporting Information [Line Items]
Sales and other operating revenues		$ 1,448	$ 1,347	$ 2,851	$ 2,709

[1] Includes related party sales. See Note 6 for additional information.