Impairment (Details) - USD ($) $ in Millions		1 Months Ended	3 Months Ended			9 Months Ended
		Mar. 31, 2025	Sep. 30, 2025	Mar. 31, 2025	Sep. 30, 2024	Sep. 30, 2025		Sep. 30, 2024	Apr. 01, 2026
Impairment (Textual)
Asset impairment loss			$ 0		$ 0	$ 1,131	[1]	$ 0
Benicia Refinery [Member] | One-time Termination Benefits [Member]
Impairment (Textual)
Retention and separation benefit liability			50			50
Refining [Member] | Benicia Refinery [Member] | One-time Termination Benefits [Member]
Impairment (Textual)
One-time costs			50			50
Operating Segments [Member] | Refining [Member]
Impairment (Textual)
Asset impairment loss		$ 1,100				1,131
Asset retirement obligation, liabilities incurred				$ 337		337
Benicia Refinery [Member]
Impairment (Textual)
Estimated fair value		722		722
Asset impairment loss	[1]					901
Incremental depreciation			$ 100			200
Benicia Refinery [Member] | Forecast [Member]
Impairment (Textual)
Property, plant, and equipment, salvage value									$ 107
Wilmington Refinery [Member]
Impairment (Textual)
Estimated fair value		$ 847		$ 847
Asset impairment loss	[1]					$ 230

[1] The asset impairment loss was recognized in our Refining segment in March 2025.