Employee Benefit Plans (Details Textual) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Defined Benefit Plan Disclosure [Line Items]
Maximum annual increase percentage to company contribution for retiree medical coverage	4.00%
Funded Status:
Amounts recognized on a before-tax bases in "Accumulated other comprehensive loss" for the company's pension and other postretirement benefit plans	$ 9,742	$ 9,279
Net Actuarial Loss:
The percentage of the higher of the projected benefit obligation or market-related value of plan assets in excess of which net actuarial losses are amortized	10.00%
Other Benefit Assumptions:
Assumed health care cost-trend rates in the next fiscal year	7.50%	8.00%
Ultimate trend rate for health care cost	4.50%	5.00%
Year when the ultimate health care cost trend rate is expected to be reached	2025	2023
Maximum annual increase in contribution rate in post retirement benefit	4.00%
Primary Investment:
Company's US and UK pension plans as a percentage of total pension assets	87.00%
Employee Savings Investment Plan:
Value of shares released from LESOP to reduce cost of total company mathcing contributions to employeee accounts within ESIP	43	38	97
Open market purchases for company matching contributions to employee accounts within ESIP	243	225	156
Employee Stock Ownership Plan:
Total expense (credits) to expense for leveraged employee stock ownership plan	1	(1)	(1)
Composition of the net credit for LESOP expense from credits that is attributable to compensation expense	2	5	6
Interest expense for LESOP debt	3	4	5
Dividends paid on the LESOP shares used to service LESOP debt	18	18	46
Company contributions to LESOP during period	2
Benefit Plan Trusts:
Number of Chevron treasury stocks held in benefit plan trust for funding obligations	14.2
Various grantor trust assets invested primarily in interest earning accounts	48	51
Employee Incentive Plan
Charges to expense for cash bonuses	898	1,217	766
U.S. [Member]
Funded Status:
Amounts recognized on a before-tax bases in "Accumulated other comprehensive loss" for the company's pension and other postretirement benefit plans	6,145	5,938
Accumulated benefit obligations pension plans	12,108	11,198
Net Actuarial Loss:
Number of years net actuarial losses recorded in "Accumulated other comprehensive loss" at December 31 for the company's US pension plans are being amortized for, over a straight-line basis	10 years
Amounts in the pension plan that will be amortized from Accumulated Other Comprehensive Income (Loss) in next fiscal year	472
Company's estimated amount that will be recognized from "Accumulated other comprehensive loss" during the next year related to lump-sum settlement costs from U.S. pension plans	230
Weighted average amortization period (in years) for recognizing prior service costs (credits) recorded in "Accumulated other comprehensive loss" at December 31 for US pension plan	10 years
Amortization of prior service (credits) costs during the next year	1
Expected Return on Plan Assets:
Estimated long-term rate of return on US pension plan assets	7.50%	7.80%	7.80%
Percentage of US pension plan assets relative to total pension plan assets	70.00%
Plan asset market valuation period, prior to year-end measurment date	3 months
Discount Rate:
Discount rate for pension plans	3.60%	3.80%	4.00%
Discount rate for post retirement benefit plans	3.90%	4.80%	5.00%
Cash Contributions and Benefit Payments:
Contributions to employee pension plans	844	1,147
Estimated contributions to employee pension plans for the next fiscal year	650
Employee Savings Investment Plan:
Contributions to employee pension plans	844	1,147
International [Member]
Funded Status:
Amounts recognized on a before-tax bases in "Accumulated other comprehensive loss" for the company's pension and other postretirement benefit plans	2,609	2,402
Accumulated benefit obligations pension plans	5,167	4,518
Net Actuarial Loss:
Number of years net actuarial losses recorded in "Accumulated other comprehensive loss" at December 31 for the company's international pension plans are being amortized for, over a straight-line basis	13 years
Amounts in the pension plan that will be amortized from Accumulated Other Comprehensive Income (Loss) in next fiscal year	143
Weighted average amortization period (in years) for recognizing prior service costs (credits) recorded in "Accumulated other comprehensive loss" at December 31 for international pension plan	13 years
Amortization of prior service (credits) costs during the next year	22
Expected Return on Plan Assets:
Estimated long-term rate of return on US pension plan assets	7.50%	7.80%	7.80%
Cash Contributions and Benefit Payments:
Contributions to employee pension plans	384	319
Estimated contributions to employee pension plans for the next fiscal year	350
Employee Savings Investment Plan:
Contributions to employee pension plans	384	319
Other Benefits [Member]
Funded Status:
Amounts recognized on a before-tax bases in "Accumulated other comprehensive loss" for the company's pension and other postretirement benefit plans	988	939
Net Actuarial Loss:
Number of years net actuarial losses recorded in "Accumulated other comprehensive loss" at December 31 for the company's OPEB plans are being amortized for, over a straight-line basis	10 years
Amounts in the pension plan that will be amortized from Accumulated Other Comprehensive Income (Loss) in next fiscal year	54
Weighted average amortization period (in years) for recognizing prior service costs (credits) recorded in "Accumulated other comprehensive loss" at December 31 for other postretirement benefit plan	11 years
Amortization of prior service (credits) costs during the next year	(50)
Cash Contributions and Benefit Payments:
Contributions to employee pension plans	199	198
Estimated contributions to employee pension plans for the next fiscal year	228
Employee Savings Investment Plan:
Contributions to employee pension plans	199	198
ESIP [Member]
Cash Contributions and Benefit Payments:
Contributions to employee pension plans	286	263	253
Employee Savings Investment Plan:
Contributions to employee pension plans	$ 286	$ 263	$ 253
Equities [Member] | U.S. [Member]
Primary Investment:
Pension Plan - Board of Trustees approved asset allocation, minimum	40.00%
Pension Plan - Board of Trustees approved asset allocation, maximum	70.00%
Equities [Member] | U.K. [Member]
Primary Investment:
Pension Plan - Board of Trustees approved asset allocation, minimum	50.00%
Pension Plan - Board of Trustees approved asset allocation, maximum	70.00%
Fixed Income and Cash [Member] | U.S. [Member]
Primary Investment:
Pension Plan - Board of Trustees approved asset allocation, minimum	20.00%
Pension Plan - Board of Trustees approved asset allocation, maximum	65.00%
Fixed Income and Cash [Member] | U.K. [Member]
Primary Investment:
Pension Plan - Board of Trustees approved asset allocation, minimum	30.00%
Pension Plan - Board of Trustees approved asset allocation, maximum	50.00%
Real Estate [Member] | U.S. [Member]
Primary Investment:
Pension Plan - Board of Trustees approved asset allocation, minimum	0.00%
Pension Plan - Board of Trustees approved asset allocation, maximum	15.00%
Other [Member] | U.S. [Member]
Primary Investment:
Pension Plan - Board of Trustees approved asset allocation, minimum	0.00%
Pension Plan - Board of Trustees approved asset allocation, maximum	5.00%