Segment Information (Segment Expenses) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Segment Reporting, Other Significant Reconciling Item [Line Items]
Segment expenses		$ 133,616	$ 135,793	$ 158,483
Operating Segments | Refining & Marketing
Segment Reporting, Other Significant Reconciling Item [Line Items]
Cost of purchases		112,938	115,973	139,660
Operating costs		5,712	5,625	5,726
Distribution costs		5,857	5,645	5,211
Other segment item	[1]	1,610	1,092	1,791
Segment expenses		126,117	128,335	152,388
Operating Segments | Midstream
Segment Reporting, Other Significant Reconciling Item [Line Items]
Other segment item	[2]	5,220	5,072	5,442
Segment expenses		5,220	5,072	5,442
Operating Segments | Renewable Diesel
Segment Reporting, Other Significant Reconciling Item [Line Items]
Operating costs		269	242	106
Distribution costs		95	82	61
Other segment item	[3]	1,960	1,345	562
Segment expenses		$ 2,324	$ 1,669	$ 729

[1] Other segment items for the Refining & Marketing segment include costs that are reimbursed by customers through commercial arrangements, as well as LIFO inventory adjustments.

[2] Other segment items for the Midstream segment include operating expenses and purchased product costs. For purposes of managing Midstream segment of MPC, the CODM is only provided consolidated Midstream expense information.

[3] Other segment items for the Renewable Diesel segment includes purchased product costs.