Segment Information (Segment Adjusted EBITDA to Income (Loss) from Continuing Operations before Income Taxes) (Detail) - USD ($) $ in Millions		3 Months Ended			9 Months Ended
	Sep. 21, 2022	Sep. 30, 2023	Sep. 30, 2022		Sep. 30, 2023	Sep. 30, 2022
Segment Reporting Information [Line Items]
Refining planned turnaround costs		$ (153)	$ (384)		$ (902)	$ (680)
Garyville incident response costs		(63)	0		(63)	0
LIFO inventory (charge) credit		0	(28)		0	(28)
Gain on sale of assets		106	1,058	[1]	106	1,058	[1]
Renewable volume obligation requirements		0	0		0	238
Litigation		0	0		0	27
Depreciation and amortization		(845)	(794)		(2,479)	(2,418)
Net interest and other financial costs		(118)	(240)		(414)	(814)
Income before income taxes		4,635	6,446		11,705	15,916
Net gain on disposal of assets		110	1,051		126	1,072
Sales-type lease, selling profit (loss)			509
Martinez Renewables LLC
Segment Reporting Information [Line Items]
Net gain on disposal of assets	$ 549
Operating Segments
Segment Reporting Information [Line Items]
Adjusted EBITDA		5,912	6,994		15,990	18,987
Operating Segments | Refining & Marketing
Segment Reporting Information [Line Items]
Adjusted EBITDA		4,373	5,496		11,389	14,630
Depreciation and amortization		(463)	(459)		(1,411)	(1,395)
Operating Segments | Midstream
Segment Reporting Information [Line Items]
Adjusted EBITDA		1,539	1,498		4,601	4,357
Depreciation and amortization		(340)	(322)		(988)	(983)
Corporate
Segment Reporting Information [Line Items]
Costs and expenses, excluding depreciation		(204)	(160)		(533)	(454)
Depreciation and amortization		$ (42)	$ (13)		$ (80)	$ (40)

[1] 2022 includes the gain of $549 million related to the contribution of assets by MPC on the formation of the Martinez Renewables LLC joint venture and the gain on lease reclassification of $509 million. See Note 13 for additional information on the formation of the Martinez Renewables LLC joint venture.