Summarized Financial Data - Chevron U.S.A. Inc. - Balance Sheet (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Subsidiary Statements Captions [Line Items]
Current assets	$ 33,671	$ 34,021
Current liabilities	29,951	27,171
Total CUSA net equity	156,118	155,642	$ 151,566	$ 149,319
Chevron U.S.A. Inc.
Subsidiary Statements Captions [Line Items]
Current assets	14,910	12,819
Other assets	58,896	55,814
Current liabilities	19,980	16,376
Other liabilities	14,763	12,906
Total CUSA net equity	39,063	39,351
Memo: Total debt	$ 3,192	$ 3,049