Disclosures About Segments And Related Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Segment Reporting Information [Line Items]
Earnings (Loss) after income tax	$ (610)	$ 2,350
Sales and other operating revenue	55,134	61,646
Upstream United States [Member]
Segment Reporting Information [Line Items]
Earnings (Loss) after income tax	(704)	96
Sales and other operating revenue	1,777	2,693
Intersegment Revenue	2,273	2,311
Upstream Non-U.S. [Member]
Segment Reporting Information [Line Items]
Earnings (Loss) after income tax	1,240	2,780
Sales and other operating revenue	2,567	3,804
Intersegment Revenue	6,387	7,129
Downstream United States [Member]
Segment Reporting Information [Line Items]
Earnings (Loss) after income tax	(101)	(161)
Sales and other operating revenue	15,384	15,642
Intersegment Revenue	3,952	4,761
Downstream Non-U.S. [Member]
Segment Reporting Information [Line Items]
Earnings (Loss) after income tax	(510)	(95)
Sales and other operating revenue	29,304	32,297
Intersegment Revenue	5,124	6,169
Chemical United States [Member]
Segment Reporting Information [Line Items]
Earnings (Loss) after income tax	288	161
Sales and other operating revenue	2,296	2,505
Intersegment Revenue	1,766	1,889
Chemical Non-U.S. [Member]
Segment Reporting Information [Line Items]
Earnings (Loss) after income tax	(144)	357
Sales and other operating revenue	3,800	4,695
Intersegment Revenue	1,263	1,547
Corporate And Financing [Member]
Segment Reporting Information [Line Items]
Earnings (Loss) after income tax	(679)	(788)
Sales and other operating revenue	6	10
Intersegment Revenue	$ 55	$ 53