Summarized Financial Data - Chevron U.S.A. Inc. (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Statement of Income - Chevron U.S.A. Inc.
Sales and other operating revenues	$ 54,296	[1]	$ 58,896	[1]
Costs and other deductions	46,535		48,636
Net income	6,178		6,471
Chevron U.S.A. Inc. [Member]
Statement of Income - Chevron U.S.A. Inc.
Sales and other operating revenues	42,777		47,134
Costs and other deductions	41,717		45,106
Net income	$ 889		$ 1,364

[1] * Includes excise, value-added and similar taxes:2,033 1,787