Summarized Financial Data - Chevron U.S.A. Inc. - Income Statement (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Sales and other operating revenues	$ 36,117	$ 15,926	$ 67,193	$ 45,631
Costs and other deductions	33,175	24,091	63,027	51,447
Net income attributable to equity method investee	$ 3,082	$ (8,270)	4,459	(4,671)
Chevron U.S.A. Inc.
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Sales and other operating revenues			51,752	32,779
Costs and other deductions			50,962	35,953
Net income attributable to equity method investee			$ 1,290	$ (2,151)