2.2.0.25falsefalse41003 - Disclosure - Leased Facilities (Net Rental Cost) (Details)truefalseIn Millionsfalse1falsefalseUSDfalsefalse1/1/2010 - 12/31/2010 USD ($) USD ($) / shares $Duration_1_1_2010_To_12_31_2010http://www.sec.gov/CIK0000034088duration2010-01-01T00:00:002010-12-31T00:00:00Unit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170Unit14Standardhttp://www.xbrl.org/2003/instancepurexbrli0Unit13Dividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0Unit15Standardhttp://xbrl.us/us-types/2009-01-31cubicFeetxbrlus0USDUSD$2falsefalseUSDfalsefalse1/1/2009 - 12/31/2009 USD ($) USD ($) / shares $Duration_1_1_2009_To_12_31_2009http://www.sec.gov/CIK0000034088duration2009-01-01T00:00:002009-12-31T00:00:00Unit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170Unit13Dividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0Unit14Standardhttp://www.xbrl.org/2003/instancepurexbrli0USDUSD$3falsefalseUSDfalsefalse1/1/2008 - 12/31/2008 USD ($) USD ($) / shares $Duration_1_1_2008_To_12_31_2008http://www.sec.gov/CIK0000034088duration2008-01-01T00:00:002008-12-31T00:00:00Unit12Standardhttp://www.xbrl.org/2003/iso4217USDiso42170Unit13Dividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0Unit14Standardhttp://www.xbrl.org/2003/instancepurexbrli0USDUSD$5false0us-gaap_LeaseAndRentalExpenseus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse37620000003762falsetruefalsefalsefalse2truefalsefalse44260000004426falsetruefalsefalsefalse3truefalsefalse41150000004115falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryRental expense incurred for leased assets including furniture and equipment which has not been recognized in costs and expenses applicable to sales and revenues; for example, cost of goods sold or other operating costs and expenses.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 13 -Paragraph 15 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 13 -Paragraph 16 -Subparagraph c falsefalse6false0us-gaap_OperatingLeasesIncomeStatementSubleaseRevenueus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse9000000090falsefalsefalsefalsefalse2truefalsefalse9800000098falsefalsefalsefalsefalse3truefalsefalse123000000123falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe amount of revenue recognized for the period under subleasing arrangements.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Technical Bulletin (FTB) -Number 88-1 -Paragraph 9 falsefalse7false0xom_NetRentalCostxomfalsedebitdurationNet Rental Costfalsefalsefalsefalsefalsefalsefalsefalsefalsefalsetotallabel1truefalsefalse36720000003672falsetruefalsefalsefalse2truefalsefalse43280000004328falsetruefalsefalsefalse3truefalsefalse39920000003992falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryNet Rental CostNo authoritative reference available.truefalse33Leased Facilities (Net Rental Cost) (Details) (USD $)MillionsUnKnownUnKnownUnKnownfalsetrue