Summarized Financial Data - Chevron U.S.A. Inc. (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
Statement of Income - Chevron U.S.A. Inc.
Sales and other operating revenues	$ 55,660	[1]	$ 61,261	[1]	$ 174,336	[1]	$ 186,344	[1]
Costs and other deductions	48,112		51,092		147,001		156,052
Net income	5,253		7,829		18,934		21,772
Chevron U.S.A. Inc. [Member]
Statement of Income - Chevron U.S.A. Inc.
Sales and other operating revenues					139,107		143,014
Costs and other deductions					132,534		135,249
Net income					$ 4,734		$ 5,733

[1] * Includes excise, value-added and similar taxes:2,163 1,974 5,879 6,372