Stock Options and Other Share-Based Compensation (Details 1) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense for stock options	$ 292	$ 283	$ 265
After tax compensation expense for stock options	190	184	172
Compensation expense for stock appreciation rights restricted stock performance units and restricted stock units	223	177	214
Compensation expense for stock appreciation rights, restricted stock, performance units and restricted stock units, After tax	145	115	139
Cash received in payment for option exercises	553	753	948
Tax benefits realized for the tax deductions from option exercises	73	101	121
Cash paid to settle performance units and stock appreciation rights	186	123	151
Maximum number of share that may be issued under LTIP from April 2004 through December 2023 (in shares)	260,000,000
For awards issued on or after May 29, 2013, the maximum number of shares that may be in a form other than a stock option, stock appreciation right or award requiring full payment for shares by the award recipient (in shares)	50,000,000
Total intrinsic value options exercised	445	580	668
Total before-tax compensation cost related to nonvested share-based compensation arrangements	259
Weighted-average period of recognition of unrecognized compensation cost related to nonvested share-based compensation arrangements (In Years)	1 year 8 months 12 days
Number of LTIP performance units outstanding (in shares)	2,531,270	2,827,757
Number of LTIP performance units granted (in shares)	776,180
Number of LTIP performance units vested outstanding (in shares)	1,007,952
Number of LTIP performance units forfeited (in shares)	64,715
Fair value of the liability recorded for LTIP performance units outstanding	312
Equivalent shares granted under various LTIP and former Texaco and Unocal programs for outstanding stock appreciation rights and other awards	2,900,000
Liability recorded for Equivalent shares granted under various LTIP and former Texaco and Unocal programs for outstanding stock appreciation rights and other awards	$ 107
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award contractual term (in years)	3 years
Stock Options and Stock Appreciation Rights [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award contractual term (in years)	10 years