Restructuring (Details) $ in Millions	12 Months Ended
	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($) People		Sep. 30, 2020 USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring expenses	$ 0	$ 0	$ 367	[1]
Restructuring reserve to be settled in cash	46	59	$ 141		$ 291	[2]
Number of positions eliminated | People			2,050
Exit and disposal costs
Restructuring Cost and Reserve [Line Items]
Restructuring expenses			$ 195
Restructuring reserve to be settled in cash	46	59	103		133
Restructuring reserve, settled without cash			51
Exit and disposal costs | Decommissioning refinery processing units and storage tanks and environmental remediation obligations
Restructuring Cost and Reserve [Line Items]
Restructuring reserve to be settled in cash			130
Employee separation costs
Restructuring Cost and Reserve [Line Items]
Restructuring expenses			172
Restructuring reserve to be settled in cash	$ 0	$ 0	38		$ 158
Employee separation costs | MPLX
Restructuring Cost and Reserve [Line Items]
Restructuring expenses			$ 37

[1] See Note 19.

[2] The restructuring reserve was zero until the third quarter of 2020.