Properties, Plants and Equipment (Schedule of Property Plant And Equipment) (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Gross PP&E	$ 38,573	$ 38,071
Accum. D&A	14,522	14,285
Net PP&E	24,051	23,786
Midstream
Property, Plant and Equipment [Line Items]
Gross PP&E	11,605	11,221
Accum. D&A	2,467	2,391
Net PP&E	9,138	8,830
Chemicals
Property, Plant and Equipment [Line Items]
Gross PP&E	0	0
Accum. D&A	0	0
Net PP&E	0	0
Refining
Property, Plant and Equipment [Line Items]
Gross PP&E	23,956	23,692
Accum. D&A	10,521	10,336
Net PP&E	13,435	13,356
Marketing and Specialties (M&S)
Property, Plant and Equipment [Line Items]
Gross PP&E	1,660	1,847
Accum. D&A	917	959
Net PP&E	743	888
Corporate and Other
Property, Plant and Equipment [Line Items]
Gross PP&E	1,352	1,311
Accum. D&A	617	599
Net PP&E	$ 735	$ 712