Summarized Financial Data - Chevron U.S.A. Inc. (Details 1) (USD $) In Millions, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012	Dec. 31, 2011
Balance Sheet - Chevron U.S.A. Inc.
Current assets	$ 56,104	$ 55,720
Current liabilities	33,413	34,212
Total Equity	144,164	137,832	131,289	122,181
Chevron U.S.A. Inc. [Member]
Balance Sheet - Chevron U.S.A. Inc.
Current assets	18,231	18,983
Other assets	53,775	52,082
Current liabilities	17,336	18,161
Other liabilities	26,721	26,472
Total Equity	27,949	26,432
Memo: Total debt	$ 14,486	$ 14,482