Equity Method Investments (Crowley Ocean Partners) (Details) - USD ($) $ in Millions		12 Months Ended
	Dec. 01, 2022	Dec. 31, 2022		Dec. 31, 2021	Dec. 31, 2020
Schedule of Equity Method Investments [Line Items]
Payments to acquire businesses, net of cash acquired		$ 413		$ 0	$ 0
Book value of equity method investment		150	[1]	0	0
Net gain on disposal of assets		$ 1,061		$ 21	$ 70
Crowley Coastal Partners, LLC
Schedule of Equity Method Investments [Line Items]
Equity method investments, ownership percentage		50.00%
Crowley Ocean Partners
Schedule of Equity Method Investments [Line Items]
Equity method investments, ownership percentage	50.00%
Payments to acquire businesses, net of cash acquired	$ 485
Repayments of Other Debt	196
Fair value of assets contributed	144
Book value of equity method investment	125
Net gain on disposal of assets	$ 19

[1] Represents the book value of MPC’s equity method investment in Watson Cogeneration Company and Crowley Ocean Partners prior to MPC buying out the remaining interest in these entities. See Note 16 for additional information