Segment Information (Income from Equity Method Investments) (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2026	Mar. 31, 2025
Segment, Reconciliation of Other Items from Segments to Consolidated [Line Items]
Income from equity method investments	$ 176	$ 230
Operating Segments \| Refining & Marketing
Segment, Reconciliation of Other Items from Segments to Consolidated [Line Items]
Income from equity method investments	(2)	5
Operating Segments \| Midstream
Segment, Reconciliation of Other Items from Segments to Consolidated [Line Items]
Income from equity method investments	207	209
Operating Segments \| Renewable Diesel
Segment, Reconciliation of Other Items from Segments to Consolidated [Line Items]
Income from equity method investments	$ (29)	$ 16

Amount of income (loss) for proportionate share of equity method investee's income (loss).

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