Disclosures About Segments And Related Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting Information [Line Items]
Earnings (Loss) after income tax	$ (1,080)	$ 3,130	$ (1,690)	$ 5,480
Sales and other operating revenue	32,277	67,491	87,411	129,137
Upstream United States [Member]
Segment Reporting Information [Line Items]
Earnings (Loss) after income tax	(1,197)	335	(1,901)	431
Sales and other operating revenue	1,081	2,594	2,858	5,287
Intersegment Revenue	1,378	2,641	3,651	4,952
Upstream Non-U.S. [Member]
Segment Reporting Information [Line Items]
Earnings (Loss) after income tax	(454)	2,926	786	5,706
Sales and other operating revenue	2,022	3,709	4,589	7,513
Intersegment Revenue	2,852	8,376	9,239	15,505
Downstream United States [Member]
Segment Reporting Information [Line Items]
Earnings (Loss) after income tax	(101)	310	(202)	149
Sales and other operating revenue	8,203	18,721	23,587	34,363
Intersegment Revenue	2,056	6,742	6,008	11,503
Downstream Non-U.S. [Member]
Segment Reporting Information [Line Items]
Earnings (Loss) after income tax	1,077	141	567	46
Sales and other operating revenue	16,302	35,306	45,606	67,603
Intersegment Revenue	2,752	6,568	7,876	12,737
Chemical United States [Member]
Segment Reporting Information [Line Items]
Earnings (Loss) after income tax	171	(6)	459	155
Sales and other operating revenue	1,570	2,504	3,866	5,009
Intersegment Revenue	1,220	2,569	2,986	4,458
Chemical Non-U.S. [Member]
Segment Reporting Information [Line Items]
Earnings (Loss) after income tax	296	194	152	551
Sales and other operating revenue	3,090	4,647	6,890	9,342
Intersegment Revenue	708	1,583	1,971	3,130
Corporate And Financing [Member]
Segment Reporting Information [Line Items]
Earnings (Loss) after income tax	(872)	(770)	(1,551)	(1,558)
Sales and other operating revenue	9	10	15	20
Intersegment Revenue	$ 56	$ 55	$ 111	$ 108