Investments and Advances (Details 2) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Variable Interest Entity [Line Items]
Term of joint venture Tengizchevroil in years	40 years
Chevron investment carrying value over underlying equity in TCO's net assets	$ 170
Percentage of affiliate by summarized financial information	100.00%
Term of joint venture with Petropiar (in years)	25 years
Equity ownership portion of Chevron in Hamaca project	30.00%
Chevron investment carrying value less underlying equity in Petropiar net assets	180
Investments and advances	23,068	22,150
Long term loans of Caspian Pipeline Consortium included in investments and advances	1,179
Percentage of Caspian Pipeline Consortium pipeline construction funded by Loans	30.00%
Chevron investment carrying value over underlying equity in Petroboscan's net assets	200
The portion of equity ownership interest held in CP Chemical by Conoco Phillips Corporation	50.00%
The portion of equity ownership interest of Star Petroleum Refining Company Ltd. held by the PTT Public Company Limited	36.00%
The portion of equity ownership interest of Caltex Australia Ltd. held by public	50.00%
Fair value of Chevron share in Caltex Australia Ltd common stock	2,690
Sale and other operating revenues from affiliated companies	17,356	20,164	13,672
Purchased crude oil and products	140,766	149,923	116,467
Accounts and notes receivable due from affiliated companies	1,207	1,968
Accounts payable due to affiliated companies	407	519
Chevron's loan to affiliates	1,494	957	1,543
Affiliated Entity [Member]
Variable Interest Entity [Line Items]
Purchased crude oil and products	6,634	7,489	5,559
Tengizchevroil LLP [Member]
Variable Interest Entity [Line Items]
Equity method investment, ownership percentage	50.00%
Petropiar [Member]
Variable Interest Entity [Line Items]
Equity method investment, ownership percentage	30.00%
Caspian Pipeline Consortium [Member]
Variable Interest Entity [Line Items]
Equity method investment, ownership percentage	15.00%
Petroboscan [Member]
Variable Interest Entity [Line Items]
Equity method investment, ownership percentage	39.00%
Angola LNG Limited [Member]
Variable Interest Entity [Line Items]
Equity method investment, ownership percentage	36.00%
GS Caltex Corporation [Member]
Variable Interest Entity [Line Items]
Equity method investment, ownership percentage	50.00%
Chevron Phillips Chemical Company LLC [Member]
Variable Interest Entity [Line Items]
Equity method investment, ownership percentage	50.00%
Star Petroleum Refining Company Limited [Member]
Variable Interest Entity [Line Items]
Equity method investment, ownership percentage	64.00%
Caltex Australia Limited [Member]
Variable Interest Entity [Line Items]
Equity method investment, ownership percentage	50.00%
Tengizchevroil LLP [Member]
Variable Interest Entity [Line Items]
Equity method investment, ownership percentage	50.00%
Percentage of affiliate by summarized financial information	100.00%
Upstream [Member]
Variable Interest Entity [Line Items]
Investments and advances	14,695	13,682
Upstream [Member] | Tengizchevroil LLP [Member]
Variable Interest Entity [Line Items]
Investments and advances	5,451	5,306
Upstream [Member] | Petropiar [Member]
Variable Interest Entity [Line Items]
Investments and advances	952	909
Upstream [Member] | Caspian Pipeline Consortium [Member]
Variable Interest Entity [Line Items]
Investments and advances	1,187	1,094
Upstream [Member] | Petroboscan [Member]
Variable Interest Entity [Line Items]
Investments and advances	1,261	1,032
Upstream [Member] | Angola LNG Limited [Member]
Variable Interest Entity [Line Items]
Investments and advances	3,186	2,921
Upstream [Member] | Other [Member]
Variable Interest Entity [Line Items]
Investments and advances	$ 2,658	$ 2,420