Property, Plant and Equipment (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Property, plant and equipment, net	$ 16,804	$ 17,665
Not Allocated to Segments [Member]
Segment Reporting Information [Line Items]
Property, plant and equipment, net	83	88
International Exploration and Production [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Property, plant and equipment, net	710	1,710
United States Exploration and Production [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Property, plant and equipment, net	$ 16,011	$ 15,867