Stock Options and Other Share-Based Compensation (Details 1) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011 Y	Dec. 31, 2010	Dec. 31, 2009
Stock Options and Other Share Based Compensation (Textual) [Abstract]
Compensation expense for stock options	$ 265	$ 229	$ 182
After tax compensation expense for stock options	172	149	119
Compensation expense for stock appreciation rights restricted stock performance units and restricted stock units	214	194	170
Compensation expense for stock appreciation rights, restricted stock, performance units and restricted stock units, After tax	139	126	110
Cash received in payment for option exercises	948	385	147
Tax benefits realized for the tax deductions from option exercises	121	66	25
Cash paid to settle performance units and stock appreciation rights	151	140	89
Maximum number of share that may be issued under LTIP from April 2004 through January 2014	160,000,000
Maximum number of shares that may be issued under the LTIP from April 2004 through January 2014 in a form other than a stock option, stock appreciation right or award requiring full payment for shares by the award recipient	64,000,000
Contractual lives for major types of awards outstanding under LTIP	vary between three years for the performance units and 10 years for the stock options and stock appreciation rights
Contractual lives of options granted under Texaco SIP (In Years)	10
Exercise period after date of grant under Texaco SIP	180 days
Total intrinsic value options exercised	668	259	91
Total before-tax compensation cost related to nonvested share-based compensation arrangements	265
Weighted-average period of recognition of unrecognized compensation cost related to nonvested share-based compensation arrangements (In Years)	1.7
Number of LTIP performance units outstanding	2,881,836	2,727,874
Number of LTIP performance units granted	1,011,200
Number of LTIP performance units vested outstanding	810,071
Number of LTIP performance units forfeited	47,167
Fair value of the liability recorded for LTIP performance units outstanding	294
Equivalent shares granted under various LTIP and former Texaco and Unocal programs for outstanding stock appreciation rights and other awards	2,200,000
Liability recorded for Equivalent shares granted under various LTIP and former Texaco and Unocal programs for outstanding stock appreciation rights and other awards	$ 62