Property, Plant and Equipment - Schedule of Historical Costs of our Property, Plant and Equipment and Related Balances (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2025	Dec. 31, 2024
Property, Plant and Equipment, Net, by Type [Abstract]
Property, plant and equipment, gross	$ 75,119	$ 71,203
Less accumulated depreciation	23,807	22,330
Subtotal property, plant and equipment, net	51,312	48,873
Capitalized major maintenance costs for reaction-based plants, net of accumulated amortization	199	189
Property, plant and equipment, net	51,511	49,062
Plants, pipelines and facilities
Property, Plant and Equipment, Net, by Type [Abstract]
Property, plant and equipment, gross	$ 64,078	60,716
Plants, pipelines and facilities | Minimum
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Life in Years	3 years
Plants, pipelines and facilities | Maximum
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Life in Years	45 years
Underground and other storage facilities
Property, Plant and Equipment, Net, by Type [Abstract]
Property, plant and equipment, gross	$ 4,792	4,704
Underground and other storage facilities | Minimum
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Life in Years	5 years
Underground and other storage facilities | Maximum
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Life in Years	40 years
Transportation equipment
Property, Plant and Equipment, Net, by Type [Abstract]
Property, plant and equipment, gross	$ 290	272
Transportation equipment | Minimum
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Life in Years	3 years
Transportation equipment | Maximum
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Life in Years	10 years
Marine vessels
Property, Plant and Equipment, Net, by Type [Abstract]
Property, plant and equipment, gross	$ 953	949
Marine vessels | Minimum
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Life in Years	15 years
Marine vessels | Maximum
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Life in Years	30 years
Land
Property, Plant and Equipment, Net, by Type [Abstract]
Property, plant and equipment, gross	$ 425	424
Construction in progress
Property, Plant and Equipment, Net, by Type [Abstract]
Property, plant and equipment, gross	$ 4,581	$ 4,138
Distillation-based and reaction-based plants | Minimum
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Life in Years	20 years
Distillation-based and reaction-based plants | Maximum
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Life in Years	35 years
Pipelines and related equipment | Minimum
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Life in Years	5 years
Pipelines and related equipment | Maximum
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Life in Years	45 years
Terminal facilities | Minimum
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Life in Years	10 years
Terminal facilities | Maximum
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Life in Years	35 years
Buildings | Minimum
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Life in Years	20 years
Buildings | Maximum
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Life in Years	40 years
Office furniture and equipment | Minimum
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Life in Years	3 years
Office furniture and equipment | Maximum
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Life in Years	20 years
Laboratory and shop equipment | Minimum
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Life in Years	5 years
Laboratory and shop equipment | Maximum
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Life in Years	35 years
Underground storage facilities | Minimum
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Life in Years	5 years
Underground storage facilities | Maximum
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Life in Years	35 years
Storage tanks | Minimum
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Life in Years	10 years
Storage tanks | Maximum
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Life in Years	40 years
Water wells | Minimum
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Life in Years	5 years
Water wells | Maximum
Property, Plant and Equipment, Net, by Type [Abstract]
Estimated Useful Life in Years	35 years
Capitalized Major Maintenance | Weighted Average
Property, Plant and Equipment, Net, by Type [Abstract]
Expected remaining amortization period	2 years 8 months 12 days