Summarized Financial Data - Chevron U.S.A. Inc. - Balance Sheet (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019	Mar. 31, 2019	Dec. 31, 2018
Subsidiary Statements Captions [Line Items]
Current assets	$ 28,562	$ 28,329
Current liabilities	28,235	26,530
Total CUSA net equity	144,914	145,208	$ 156,118	$ 155,642
Chevron U.S.A. Inc.
Subsidiary Statements Captions [Line Items]
Current assets	10,773	13,059
Other assets	51,449	50,796
Current liabilities	16,143	18,291
Other liabilities	12,630	12,565
Total CUSA net equity	33,449	32,999
Memo: Total debt	$ 3,219	$ 3,222