Disclosures About Segments And Related Information (Schedule Of Segments And Related Information) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018		Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Earnings after income tax	[1]	$ 20,840		$ 19,710	$ 7,840
Earnings of equity companies included above		7,355		5,380	4,806
Sales and other operating revenue		279,332		237,162	200,628
Depreciation and depletion expense		18,745		19,893	22,308
Interest revenue		64		36	30
Interest expense		766		601	453
Income taxes expense (benefit)		9,532		(1,174)	(406)
Additions to property, plant and equipment		20,051		24,901	16,100
Investments in equity companies		26,382		24,354	20,810
Total assets		346,196		348,691	330,314
Effect of U.S. tax reform - noncash
Segment Reporting Information [Line Items]
Effect of U.S. tax reform		(291)		(5,942)
U.S. [Member]
Segment Reporting Information [Line Items]
Income taxes expense (benefit)		1,145		(8,561)	(3,040)
Non-U.S. [Member]
Segment Reporting Information [Line Items]
Income taxes expense (benefit)		8,387		7,387	2,634
Upstream [Member] | U.S. [Member]
Segment Reporting Information [Line Items]
Earnings after income tax		1,739	[1]	6,622	(4,151)
Earnings of equity companies included above		608		216	53
Sales and other operating revenue		10,359		9,349	7,552
Intersegment revenue		8,683		5,729	3,827
Depreciation and depletion expense		6,024		6,963	9,626
Interest expense		77		87	17
Income taxes expense (benefit)		104		(8,552)	(2,600)
Additions to property, plant and equipment		7,119		9,761	3,144
Investments in equity companies		4,566		4,680	4,917
Total assets		90,310		89,048	86,146
Upstream [Member] | U.S. [Member] | Effect of U.S. tax reform - noncash
Segment Reporting Information [Line Items]
Effect of U.S. tax reform				(7,602)
Upstream [Member] | Non-U.S. [Member]
Segment Reporting Information [Line Items]
Earnings after income tax		12,340	[1]	6,733	4,347
Earnings of equity companies included above		5,816		3,618	3,359
Sales and other operating revenue		15,158		14,508	12,278
Intersegment revenue		29,659		22,935	18,099
Depreciation and depletion expense		9,257		9,741	9,550
Interest expense		31		29	29
Income taxes expense (benefit)		8,149		5,463	1,818
Additions to property, plant and equipment		7,974		8,617	7,878
Investments in equity companies		16,337		14,494	11,364
Total assets		148,914		155,822	153,183
Upstream [Member] | Non-U.S. [Member] | Effect of U.S. tax reform - noncash
Segment Reporting Information [Line Items]
Effect of U.S. tax reform				480
Downstream [Member] | U.S. [Member]
Segment Reporting Information [Line Items]
Earnings after income tax		2,962	[1]	1,948	1,094
Earnings of equity companies included above		156		118	58
Sales and other operating revenue		74,327		61,695	52,630
Intersegment revenue		21,954		14,857	11,796
Depreciation and depletion expense		684		658	628
Interest expense		2		1	1
Income taxes expense (benefit)		946		(61)	396
Additions to property, plant and equipment		1,152		769	791
Investments in equity companies		293		276	111
Total assets		17,898		18,172	16,201
Downstream [Member] | U.S. [Member] | Effect of U.S. tax reform - noncash
Segment Reporting Information [Line Items]
Effect of U.S. tax reform				(618)
Downstream [Member] | Non-U.S. [Member]
Segment Reporting Information [Line Items]
Earnings after income tax		3,048	[1]	3,649	3,107
Earnings of equity companies included above		(6)		490	404
Sales and other operating revenue		147,007		122,881	102,756
Intersegment revenue		29,888		22,263	18,775
Depreciation and depletion expense		890		883	889
Interest expense		12		6	8
Income taxes expense (benefit)		1,008		934	951
Additions to property, plant and equipment		1,595		1,551	1,525
Investments in equity companies		1,162		1,462	1,255
Total assets		34,024		34,294	29,208
Chemical [Member] | U.S. [Member]
Segment Reporting Information [Line Items]
Earnings after income tax		1,642	[1]	2,190	1,876
Earnings of equity companies included above		48		90	111
Sales and other operating revenue		12,239		11,035	9,944
Intersegment revenue		9,044		7,270	6,404
Depreciation and depletion expense		405		299	275
Income taxes expense (benefit)		566		362	693
Additions to property, plant and equipment		1,146		1,330	1,463
Investments in equity companies		870		341	158
Total assets		14,904		13,363	11,600
Chemical [Member] | U.S. [Member] | Effect of U.S. tax reform - noncash
Segment Reporting Information [Line Items]
Effect of U.S. tax reform				(335)
Chemical [Member] | Non-U.S. [Member]
Segment Reporting Information [Line Items]
Earnings after income tax		1,709	[1]	2,328	2,739
Earnings of equity companies included above		1,113		1,217	1,188
Sales and other operating revenue		20,204		17,659	15,447
Intersegment revenue		7,217		5,550	4,211
Depreciation and depletion expense		606		504	477
Interest expense		1
Income taxes expense (benefit)		245		664	609
Additions to property, plant and equipment		348		2,019	482
Investments in equity companies		3,431		3,387	3,247
Total assets		21,131		21,133	18,453
Corporate And Financing [Member]
Segment Reporting Information [Line Items]
Earnings after income tax		(2,600)	[1]	(3,760)	(1,172)
Earnings of equity companies included above		(380)		(369)	(367)
Sales and other operating revenue		38		35	21
Intersegment revenue		205		208	236
Depreciation and depletion expense		879		845	863
Interest revenue		64		36	30
Interest expense		643		478	398
Income taxes expense (benefit)		(1,486)		16	(2,273)
Additions to property, plant and equipment		717		854	817
Investments in equity companies		(277)		(286)	(242)
Total assets		$ 19,015		16,859	$ 15,523
Corporate And Financing [Member] | Effect of U.S. tax reform - noncash
Segment Reporting Information [Line Items]
Effect of U.S. tax reform				$ 2,133

[1] See Note 2 for additional details regarding the change in segmentation of Non-service pension and postretirement benefit expense .