Revenues and Segment Information, Total Assets by Reportable Segments (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Total Assets by Reportable Segments
Reportable segment assets	$ 50,155	$ 50,158
Equity Method Investments (Textual):
Investments in joint ventures	542	530
Refining [Member]
Equity Method Investments (Textual):
Investments in joint ventures	542	530
Operating Segments [Member] | Refining [Member]
Total Assets by Reportable Segments
Reportable segment assets	42,673	40,382
Operating Segments [Member] | Ethanol [Member]
Total Assets by Reportable Segments
Reportable segment assets	1,691	1,344
Operating Segments [Member] | VLP [Member]
Total Assets by Reportable Segments
Reportable segment assets	1,620	1,517
Corporate and Eliminations [Member]
Total Assets by Reportable Segments
Reportable segment assets	$ 4,171	$ 6,915