Summarized Financial Data - Chevron U.S.A. Inc. - Income Statement (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Sales and other operating revenues	$ 15,926	$ 36,323	$ 45,631	$ 70,512
Costs and other deductions	24,091	32,915	51,447	64,158
Net income attributable to equity method investee	$ (8,270)	$ 4,305	(4,671)	6,954
Chevron U.S.A. Inc.
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Sales and other operating revenues			32,779	54,777
Costs and other deductions			35,953	53,424
Net income attributable to equity method investee			$ (2,151)	$ 1,225