2.2.0.25truefalse1871 - Disclosure - Contingencies - Tronox (Detail)truefalseIn Millions, unless otherwise specifiedfalse1falsefalseUSDtruefalse{us-gaap_LossContingenciesByNatureOfContingencyAxis} : Tronox Environmental And Litigation Trust [Member] {apc_RegionReportingInformationByRegionAxis} : Tronox Plan Reorganization [Member] 12/31/2010 USD ($) $AS_OF_Dec31_2010_us-gaap_LossContingenciesByNatureOfContingencyAxis_TronoxEnvironmentalAndLitigationTrustMember_apc_RegionReportingInformationByRegionAxis_TronoxPlanReorganizationMemberhttp://www.sec.gov/CIK0000773910instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseTronox Environmental And Litigation Trust [Member]us-gaap_LossContingenciesByNatureOfContingencyAxisxbrldihttp://xbrl.org/2006/xbrldiapc_TronoxEnvironmentalAndLitigationTrustMemberus-gaap_LossContingenciesByNatureOfContingencyAxisexplicitMemberfalsefalseTronox Plan Reorganization [Member]apc_RegionReportingInformationByRegionAxisxbrldihttp://xbrl.org/2006/xbrldiapc_TronoxPlanReorganizationMemberapc_RegionReportingInformationByRegionAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli0USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$2falsefalseUSDtruefalse{us-gaap_LossContingenciesByNatureOfContingencyAxis} : Tronox Tort Claims Trust [Member] {apc_RegionReportingInformationByRegionAxis} : Tronox Plan Reorganization [Member] 12/31/2010 USD ($) $AS_OF_Dec31_2010_apc_RegionReportingInformationByRegionAxis_TronoxPlanReorganizationMember_us-gaap_LossContingenciesByNatureOfContingencyAxis_TronoxTortClaimsTrustMemberhttp://www.sec.gov/CIK0000773910instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseTronox Tort Claims Trust [Member]us-gaap_LossContingenciesByNatureOfContingencyAxisxbrldihttp://xbrl.org/2006/xbrldiapc_TronoxTortClaimsTrustMemberus-gaap_LossContingenciesByNatureOfContingencyAxisexplicitMemberfalsefalseTronox Plan Reorganization [Member]apc_RegionReportingInformationByRegionAxisxbrldihttp://xbrl.org/2006/xbrldiapc_TronoxPlanReorganizationMemberapc_RegionReportingInformationByRegionAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli0USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$3falsefalsetruefalse{us-gaap_LossContingenciesByNatureOfContingencyAxis} : Tronox General Unsecured Claims [Member] {apc_RegionReportingInformationByRegionAxis} : Tronox Plan Reorganization [Member] 12/31/2010 AS_OF_Dec31_2010_us-gaap_LossContingenciesByNatureOfContingencyAxis_TronoxGeneralUnsecuredClaimsMember_apc_RegionReportingInformationByRegionAxis_TronoxPlanReorganizationMemberhttp://www.sec.gov/CIK0000773910instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseTronox General Unsecured Claims [Member]us-gaap_LossContingenciesByNatureOfContingencyAxisxbrldihttp://xbrl.org/2006/xbrldiapc_TronoxGeneralUnsecuredClaimsMemberus-gaap_LossContingenciesByNatureOfContingencyAxisexplicitMemberfalsefalseTronox Plan Reorganization [Member]apc_RegionReportingInformationByRegionAxisxbrldihttp://xbrl.org/2006/xbrldiapc_TronoxPlanReorganizationMemberapc_RegionReportingInformationByRegionAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli04falsefalseUSDtruefalse{us-gaap_LossContingenciesByNatureOfContingencyAxis} : Master Separation Agreement [Member] 7/1/2010 - 9/30/2010 USD ($) $FROM_Jul01_2010_TO_Sep30_2010_us-gaap_LossContingenciesByNatureOfContingencyAxis_MasterSeparationAgreementMemberhttp://www.sec.gov/CIK0000773910duration2010-07-01T00:00:002010-09-30T00:00:00falsefalseMaster Separation Agreement [Member]us-gaap_LossContingenciesByNatureOfContingencyAxisxbrldihttp://xbrl.org/2006/xbrldiapc_MasterSeparationAgreementMemberus-gaap_LossContingenciesByNatureOfContingencyAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$5falsefalseUSDtruefalse{us-gaap_LossContingenciesByNatureOfContingencyAxis} : Master Separation Agreement [Member] {apc_RegionReportingInformationByRegionAxis} : Stipulation and Agreed Order [Member] 2/28/2011 USD ($) $AS_OF_Feb28_2011_us-gaap_LossContingenciesByNatureOfContingencyAxis_MasterSeparationAgreementMember_apc_RegionReportingInformationByRegionAxis_StipulationAndAgreedOrderMemberhttp://www.sec.gov/CIK0000773910instant2011-02-28T00:00:000001-01-01T00:00:00falsefalseMaster Separation Agreement [Member]us-gaap_LossContingenciesByNatureOfContingencyAxisxbrldihttp://xbrl.org/2006/xbrldiapc_MasterSeparationAgreementMemberus-gaap_LossContingenciesByNatureOfContingencyAxisexplicitMemberfalsefalseStipulation and Agreed Order [Member]apc_RegionReportingInformationByRegionAxisxbrldihttp://xbrl.org/2006/xbrldiapc_StipulationAndAgreedOrderMemberapc_RegionReportingInformationByRegionAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$2false0apc_ReversalOfTronoxReimbursementObligationapcfalsecreditdurationReversal of Tronox reimbursement obligationfalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsetruefalse2falsefalsefalse00falsefalsefalsetruefalse3falsefalsefalse00falsefalsefalsetruefalse4truefalsefalse9500000095falsetruefalsetruefalse5falsefalsefalse00falsefalsefalsetruefalseMonetaryxbrli:monetaryItemTypemonetaryReversal of Tronox reimbursement obligationNo authoritative reference available.falsefalseReversal of Tronox reimbursement obligation3false0apc_ValueOfAgreedUponClaimapcfalsedebitinstantValue of agreed-upon claimfalsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsetruefalse2falsefalsefalse00falsefalsefalsetruefalse3falsefalsefalse00falsefalsefalsetruefalse4falsefalsefalse00falsefalsefalsetruefalse5truefalsefalse2900000029falsefalsefalsetruefalseMonetaryxbrli:monetaryItemTypemonetaryValue of agreed-upon claimNo authoritative reference available.falsefalseValue of agreed-upon claim4false0apc_CashTrustContributionapcfalsedebitinstantThe amount of cash be contributed by Tronox.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse270000000270falsefalsefalsetruefalse2truefalsefalse1300000013falsefalsefalsetruefalse3falsefalsefalse00falsefalsefalsetruefalse4falsefalsefalse00falsefalsefalsetruefalse5falsefalsefalse00falsefalsefalsetruefalseMonetaryxbrli:monetaryItemTypemonetaryThe amount of cash be contributed by Tronox.No authoritative reference available.falsefalseProposed cash to be contributed by Tronox5false0apc_PercentageOfProceedsFromAdversaryProceedingapcfalsenainstantPercentage of proceeds from Adversary Proceedingfalsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truetruefalse0.880.88falsefalsefalsetruefalse2truetruefalse0.120.12falsefalsefalsetruefalse3falsetruefalse00falsefalsefalsetruefalse4falsetruefalse00falsefalsefalsetruefalse5falsetruefalse00falsefalsefalsetruefalseOtherus-types:percentItemTypepurePercentage of proceeds from Adversary ProceedingNo authoritative reference available.falsefalseProposed percentage of proceeds from Adversary Proceeding6false0apc_AssetTrustContributionapcfalsedebitinstantThe value of assets to be contributed by Tronox.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse5000000050falsetruefalsetruefalse2falsefalsefalse00falsefalsefalsetruefalse3falsefalsefalse00falsefalsefalsetruefalse4falsefalsefalse00falsefalsefalsetruefalse5falsefalsefalse00falsefalsefalsetruefalseMonetaryxbrli:monetaryItemTypemonetaryThe value of assets to be contributed by Tronox.No authoritative reference available.falsefalseProposed value of assets to be contributed by Tronox7false0apc_PercentageOfCommonEquityapcfalsenainstantPercentage of common equity of reorganized Tronox.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsetruefalse00falsefalsefalsetruefalse2falsetruefalse00falsefalsefalsetruefalse3truetruefalse0.5090.509falsefalsefalsetruefalse4falsetruefalse00falsefalsefalsetruefalse5falsetruefalse00falsefalsefalsetruefalseOtherus-types:percentItemTypepurePercentage of common equity of reorganized Tronox.No authoritative reference available.falsefalseProposed percentage of common equity of reorganized Tronox8false0apc_RightToPurchasePercentageOfCommonEquityapcfalsenainstantRight to purchase a percentage of common equity of reorganized Tronox.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsetruefalse00falsefalsefalsetruefalse2falsetruefalse00falsefalsefalsetruefalse3truetruefalse0.4550.455falsefalsefalsetruefalse4falsetruefalse00falsefalsefalsetruefalse5falsetruefalse00falsefalsefalsetruefalseOtherus-types:percentItemTypepureRight to purchase a percentage of common equity of reorganized Tronox.No authoritative reference available.falsefalseProposed right to purchase percentage of common equity of reorganized Tronox57Contingencies - Tronox (Detail) (USD $)MillionsUnKnownUnKnownUnKnowntruetrue