2.2.0.25truefalse1570 - Disclosure - Noncontrolling Interests - Additional Information (Detail)truefalseIn Millions, unless otherwise specifiedfalse1falsefalseUSDfalsefalse1/1/2010 - 12/31/2010 USD ($) / shares USD ($) $FROM_Jan01_2010_TO_Dec31_2010http://www.sec.gov/CIK0000773910duration2010-01-01T00:00:002010-12-31T00:00:00usdPerShrDividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170PureStandardhttp://www.xbrl.org/2003/instancepurexbrli0SharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0MMboeStandardhttp://www.anadarko.com/20101231MMboeapc0USDUSD$2falsefalseUSDfalsefalse1/1/2009 - 12/31/2009 USD ($) USD ($) / shares $FROM_Jan01_2009_TO_Dec31_2009http://www.sec.gov/CIK0000773910duration2009-01-01T00:00:002009-12-31T00:00:00USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170usdPerShrDividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0MMboeStandardhttp://www.anadarko.com/20101231MMboeapc0PureStandardhttp://www.xbrl.org/2003/instancepurexbrli0SharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0USDUSD$3falsefalseUSDfalsefalse1/1/2008 - 12/31/2008 USD ($) USD ($) / shares $FROM_Jan01_2008_TO_Dec31_2008http://www.sec.gov/CIK0000773910duration2008-01-01T00:00:002008-12-31T00:00:00USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170SharesStandardhttp://www.xbrl.org/2003/instancesharesxbrli0MMboeStandardhttp://www.anadarko.com/20101231MMboeapc0usdPerShrDividehttp://www.xbrl.org/2003/iso4217USDiso4217http://www.xbrl.org/2003/instancesharesxbrli0PureStandardhttp://www.xbrl.org/2003/instancepurexbrli0USDUSD$4falsefalseUSDtruefalse{us-gaap_PartnerCapitalComponentsAxis} : Western Gas Partners Limited Partnership [Member] 12/1/2009 - 12/31/2009 USD ($) $FROM_Dec01_2009_TO_Dec31_2009_us-gaap_PartnerCapitalComponentsAxis_WesternGasPartnersLimitedPartnershipMemberhttp://www.sec.gov/CIK0000773910duration2009-12-01T00:00:002009-12-31T00:00:00falsefalseWestern Gas Partners Limited Partnership [Member]us-gaap_PartnerCapitalComponentsAxisxbrldihttp://xbrl.org/2006/xbrldiapc_WesternGasPartnersLimitedPartnershipMemberus-gaap_PartnerCapitalComponentsAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170CommonUnitsStandardhttp://www.anadarko.com/20101231CommonUnitsapc0USDUSD$5falsefalseUSDtruefalse{us-gaap_PartnerCapitalComponentsAxis} : Western Gas Partners Limited Partnership [Member] 1/1/2010 - 12/31/2010 USD ($) $FROM_Jan01_2010_TO_Dec31_2010_us-gaap_PartnerCapitalComponentsAxis_WesternGasPartnersLimitedPartnershipMemberhttp://www.sec.gov/CIK0000773910duration2010-01-01T00:00:002010-12-31T00:00:00falsefalseWestern Gas Partners Limited Partnership [Member]us-gaap_PartnerCapitalComponentsAxisxbrldihttp://xbrl.org/2006/xbrldiapc_WesternGasPartnersLimitedPartnershipMemberus-gaap_PartnerCapitalComponentsAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170CommonUnitsStandardhttp://www.anadarko.com/20101231CommonUnitsapc0USDUSD$6falsefalsetruefalse{us-gaap_PartnerCapitalComponentsAxis} : Western Gas Partners Limited Partnership [Member] {us-gaap_RelatedPartyTransactionsByRelatedPartyAxis} : Limited Partner [Member] 12/31/2010 AS_OF_Dec31_2010_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_LimitedPartnerMember_us-gaap_PartnerCapitalComponentsAxis_WesternGasPartnersLimitedPartnershipMemberhttp://www.sec.gov/CIK0000773910instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseWestern Gas Partners Limited Partnership [Member]us-gaap_PartnerCapitalComponentsAxisxbrldihttp://xbrl.org/2006/xbrldiapc_WesternGasPartnersLimitedPartnershipMemberus-gaap_PartnerCapitalComponentsAxisexplicitMemberfalsefalseLimited Partner [Member]us-gaap_RelatedPartyTransactionsByRelatedPartyAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_LimitedPartnerMemberus-gaap_RelatedPartyTransactionsByRelatedPartyAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli07falsefalsetruefalse{us-gaap_PartnerCapitalComponentsAxis} : Western Gas Partners Limited Partnership [Member] {us-gaap_RelatedPartyTransactionsByRelatedPartyAxis} : General Partner [Member] 12/31/2010 AS_OF_Dec31_2010_us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_GeneralPartnerMember_us-gaap_PartnerCapitalComponentsAxis_WesternGasPartnersLimitedPartnershipMemberhttp://www.sec.gov/CIK0000773910instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseWestern Gas Partners Limited Partnership [Member]us-gaap_PartnerCapitalComponentsAxisxbrldihttp://xbrl.org/2006/xbrldiapc_WesternGasPartnersLimitedPartnershipMemberus-gaap_PartnerCapitalComponentsAxisexplicitMemberfalsefalseGeneral Partner [Member]us-gaap_RelatedPartyTransactionsByRelatedPartyAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_GeneralPartnerMemberus-gaap_RelatedPartyTransactionsByRelatedPartyAxisexplicitMemberPureStandardhttp://www.xbrl.org/2003/instancepurexbrli02false0apc_LimitedPartnerCapitalAccountUnitsIssuedapcfalsenainstantThe number of limited partner units issued. The limited partners are partners of a publicly traded limited partnership or...falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalse4truefalsefalse70000007000000falsefalsefalsetruefalse5truefalsefalse1300000013000000falsefalsefalsetruefalse6falsefalsefalse00falsefalsefalsetruefalse7falsefalsefalse00falsefalsefalsetruefalseOtherxbrli:integerItemTypeintegerThe number of limited partner units issued. The limited partners are partners of a publicly traded limited partnership or master limited partnership. Limited partners have limited liability and do not manage the partnership.No authoritative reference available.falsefalseIssuance of common units, representing limited partner interests to the public3false0apc_ProceedsFromSaleOfPreviouslyUnissuedStockBySubsidiaryOrEquityInvesteeapcfalsedebitdurationProceeds from sales of previously unissued stock by subsidiaries or equity investees made to investors outside the...falsefalsefalsefalsefalsefalsefalsefalsefalsefalseterselabel1truefalsefalse338000000338falsetruefalsefalsefalse2truefalsefalse120000000120falsetruefalsefalsefalse3truefalsefalse343000000343falsetruefalsefalsefalse4truefalsefalse120000000120falsetruefalsetruefalse5truefalsefalse338000000338falsetruefalsetruefalse6falsefalsefalse00falsefalsefalsetruefalse7falsefalsefalse00falsefalsefalsetruefalseMonetaryxbrli:monetaryItemTypemonetaryProceeds from sales of previously unissued stock by subsidiaries or equity investees made to investors outside the consolidated group.No authoritative reference available.falsefalseProceeds raised from offering by subsidiary4false0us-gaap_MinorityInterestIncreaseFromStockIssuanceus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse338000000338falsefalsefalsefalsefalse2truefalsefalse120000000120falsefalsefalsefalsefalse3truefalsefalse343000000343falsefalsefalsefalsefalse4truefalsefalse120000000120falsefalsefalsetruefalse5truefalsefalse338000000338falsefalsefalsetruefalse6falsefalsefalse00falsefalsefalsetruefalse7falsefalsefalse00falsefalsefalsetruefalseMonetaryxbrli:monetaryItemTypemonetaryIncrease in noncontrolling interest balance from issuance of additional shares to noncontrolling interest holders or the sale of all or a portion of the parent's equity interest.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph c(2) falsefalseIncrease in noncontrolling interest from offering by subsidiary5false0apc_AmountOfNoncontrollingInterestsThatWillBeTransferredToPaidInCapitalUponConversionOfUnitsapcfalsecreditinstantAmount of noncontrolling interests that will be transferred to paid-in capital upon conversion of units.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1falsefalsefalse00falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalse3falsefalsefalse00falsefalsefalsefalsefalse4falsefalsefalse00falsefalsefalsetruefalse5truefalsefalse143000000143falsetruefalsetruefalse6falsefalsefalse00falsefalsefalsetruefalse7falsefalsefalse00falsefalsefalsetruefalseMonetaryxbrli:monetaryItemTypemonetaryAmount of noncontrolling interests that will be transferred to paid-in capital upon conversion of units.No authoritative reference available.falsefalseAmount of noncontrolling interests that transferred to paid-in capital if the Western Gas Partners, LP subordinated units convert to common units6false0us-gaap_MinorityInterestOwnershipPercentageByParentus-gaaptruenainstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsetruefalse00falsefalsefalsefalsefalse2falsetruefalse00falsefalsefalsefalsefalse3falsetruefalse00falsefalsefalsefalsefalse4falsetruefalse00falsefalsefalsetruefalse5falsetruefalse00falsefalsefalsetruefalse6truetruefalse0.4650.465falsefalsefalsetruefalse7truetruefalse0.020.02falsefalsefalsetruefalseOtherus-types:percentItemTypepureThe consolidating entity's interest in net assets of the subsidiary, expressed as a percentage.No authoritative reference available.falsefalseAnadarko partner interest in Western Gas Partners75Noncontrolling Interests - Additional Information (Detail) (USD $)MillionsUnKnownUnKnownUnKnowntruetrue