Operating Segments and Geographic Data (Details 2) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Sales and other operating revenues
Sales and other operating revenues	$ 244,371	[1]	$ 198,198	[1]	$ 167,402	[1]
Operating Segments and Geographic Data (Textual) [Abstract]
Contribution in company's total sales and other operating revenues by a country other than United States	Less than 10%
Upstream [Member]
Sales and other operating revenues
Sales and other operating revenues	82,836		65,289		51,462
Upstream [Member] | Total United States [Member]
Sales and other operating revenues
Sales and other operating revenues	27,738		24,155		19,522
Upstream [Member] | United States [Member]
Sales and other operating revenues
Sales and other operating revenues	9,623		10,316		9,225
Upstream [Member] | Intersegment [Member]
Sales and other operating revenues
Sales and other operating revenues	18,115		13,839		10,297
Upstream [Member] | International [Member]
Sales and other operating revenues
Sales and other operating revenues	55,098		41,134		31,940
Upstream [Member] | International [Member]
Sales and other operating revenues
Sales and other operating revenues	20,086		17,300		13,463
Upstream [Member] | Intersegment [Member]
Sales and other operating revenues
Sales and other operating revenues	35,012		23,834		18,477
Downstream [Member]
Sales and other operating revenues
Sales and other operating revenues	214,299		170,157		144,195
Downstream [Member] | Total United States [Member]
Sales and other operating revenues
Sales and other operating revenues	91,078		75,035		62,727
Downstream [Member] | United States [Member]
Sales and other operating revenues
Sales and other operating revenues	86,793		70,436		58,056
Downstream [Member] | Excise and Similar Taxes [Member]
Sales and other operating revenues
Sales and other operating revenues	4,199		4,484		4,573
Downstream [Member] | Intersegment [Member]
Sales and other operating revenues
Sales and other operating revenues	86		115		98
Downstream [Member] | International [Member]
Sales and other operating revenues
Sales and other operating revenues	123,221		95,122		81,468
Downstream [Member] | International [Member]
Sales and other operating revenues
Sales and other operating revenues	119,254		90,922		77,845
Downstream [Member] | Excise and Similar Taxes [Member]
Sales and other operating revenues
Sales and other operating revenues	3,886		4,107		3,536
Downstream [Member] | Intersegment [Member]
Sales and other operating revenues
Sales and other operating revenues	81		93		87
All Other Segments [Member]
Sales and other operating revenues
Sales and other operating revenues	1,644		1,619		1,701
All Other Segments [Member] | Total United States [Member]
Sales and other operating revenues
Sales and other operating revenues	1,598		1,557		1,629
All Other Segments [Member] | United States [Member]
Sales and other operating revenues
Sales and other operating revenues	526		610		665
All Other Segments [Member] | Intersegment [Member]
Sales and other operating revenues
Sales and other operating revenues	1,072		947		964
All Other Segments [Member] | International [Member]
Sales and other operating revenues
Sales and other operating revenues	46		62		72
All Other Segments [Member] | International [Member]
Sales and other operating revenues
Sales and other operating revenues	4		23		39
All Other Segments [Member] | Intersegment [Member]
Sales and other operating revenues
Sales and other operating revenues	42		39		33
Sales and Other Operating Revenue [Member]
Sales and other operating revenues
Sales and other operating revenues	298,779		237,065		197,358
Sales and Other Operating Revenue [Member] | United States [Member]
Sales and other operating revenues
Sales and other operating revenues	120,414		100,747		83,878
Sales and Other Operating Revenue [Member] | Intersegment [Member]
Sales and other operating revenues
Sales and other operating revenues	178,365		136,318		113,480
Sales and Other Operating Revenue [Member] | Elimination of Intersegment Sales [Member]
Sales and other operating revenues
Sales and other operating revenues	$ (54,408)		$ (38,867)		$ (29,956)

[1] Includes excise, value-added and similar taxes.