Summarized Financial Data - Chevron U.S.A. Inc. (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Income - Chevron U.S.A. Inc.
Sales and other operating revenues	[1]	$ 33,892	$ 29,159	$ 98,293	$ 80,073
Costs and other deductions		33,547	29,031	96,366	85,647
Net income (loss) attributable to CUSA		$ 1,952	$ 1,283	6,084	(912)
Chevron U.S.A. Inc.
Statement of Income - Chevron U.S.A. Inc.
Sales and other operating revenues				75,759	60,882
Costs and other deductions				75,403	63,596
Net income (loss) attributable to CUSA				$ 1,315	$ (917)

[1] Includes excise, value-added and similar taxes: $1,867, $1,772, $5,315, $5,208