Revenue (Disaggregated by Product Line) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Sales and other operating revenues		$ 32,321	$ 17,408	$ 84,647	$ 51,807
Refining & Marketing
Sales and other operating revenues	[1]	31,109	16,493	81,324	49,164
Refining & Marketing | Refined products
Sales and other operating revenues		29,257	15,356	75,594	45,893
Refining & Marketing | Crude oil
Sales and other operating revenues		1,687	990	4,999	2,868
Refining & Marketing | Services and other
Sales and other operating revenues		165	147	731	403
Midstream
Sales and other operating revenues	[1]	1,212	915	3,323	2,643
Midstream | Refined products
Sales and other operating revenues		441	166	1,027	460
Midstream | Services and other
Sales and other operating revenues		$ 771	$ 749	$ 2,296	$ 2,183

[1] Includes Refining & Marketing intercompany sales to Speedway prior to May 14, 2021 and related party sales. See Notes 4 and 8 for additional information