Disclosures About Segments And Related Information (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2012		Sep. 30, 2011
Segment Reporting Information [Line Items]
Earnings after income tax	$ 9,570		$ 10,330		$ 34,930		$ 31,660
Sales and other operating revenue	111,554	[1],[2]	120,475	[1],[2]	343,488	[1],[2]	351,120	[1],[2]
Upstream United States [Member]
Segment Reporting Information [Line Items]
Earnings after income tax	633		1,184		2,321		3,912
Sales and other operating revenue	2,830	[1]	3,686	[1]	8,404	[1]	10,601	[1]
Intersegment revenue	1,935		2,232		6,538		7,189
Upstream Non-U.S. [Member]
Segment Reporting Information [Line Items]
Earnings after income tax	5,340		7,210		19,812		21,698
Sales and other operating revenue	7,208	[1]	7,101	[1]	22,163	[1]	24,684	[1]
Intersegment revenue	11,105		12,527		35,171		37,705
Downstream United States [Member]
Segment Reporting Information [Line Items]
Earnings after income tax	1,441		810		2,878		2,238
Sales and other operating revenue	31,621	[1]	31,329	[1]	92,991	[1]	90,904	[1]
Intersegment revenue	5,422		4,426		16,214		14,071
Downstream Non-U.S. [Member]
Segment Reporting Information [Line Items]
Earnings after income tax	1,749		769		8,544	[3]	1,796
Sales and other operating revenue	60,763	[1]	67,591	[1]	190,590	[1]	192,742	[1]
Intersegment revenue	15,309		17,854		47,215		53,987
Chemical United States [Member]
Segment Reporting Information [Line Items]
Earnings after income tax	565		538		1,492		1,832
Sales and other operating revenue	3,493	[1]	4,053	[1]	11,167	[1]	11,829	[1]
Intersegment revenue	3,301		2,884		9,429		9,202
Chemical Non-U.S. [Member]
Segment Reporting Information [Line Items]
Earnings after income tax	225		465		1,448	[3]	2,008
Sales and other operating revenue	5,634	[1]	6,711	[1]	18,157	[1]	20,345	[1]
Intersegment revenue	2,292		2,960		7,565		8,095
All Other [Member]
Segment Reporting Information [Line Items]
Earnings after income tax	(383)		(646)		(1,565)		(1,824)
Sales and other operating revenue	5	[1]	4	[1]	16	[1]	15	[1]
Intersegment revenue	$ 75		$ 66		$ 212		$ 192

[1] Includes sales-based taxes

[2] Sales-based taxes included in sales and other operating revenue for the three months ended September 30, 2012, and 2011, were $8,137 million and $8,484 million, respectively, and for the nine months ended September 30, 2012, and 2011, were $24,657 million and $25,013 million, respectively.

[3] Nine months ended September 30, 2012, includes the gain associated with the Japan restructuring (See Note 9) of $5.3 billion in the non-U.S. Downstream and $0.6 billion in the non-U.S. Chemical segments.