2.2.0.25truefalse1680 - Disclosure - Asset Retirement Obligations Rollforward (Parenthetical) (Detail)truefalseIn Millionsfalse1falsefalseUSDtruefalse{apc_AssetRetirementObligationByBalanceSheetLocationAxis} : Accrued Liabilities [Member] 12/31/2010 USD ($) $AS_OF_Dec31_2010_apc_AssetRetirementObligationByBalanceSheetLocationAxis_AccruedLiabilitiesMemberhttp://www.sec.gov/CIK0000773910instant2010-12-31T00:00:000001-01-01T00:00:00falsefalseAccrued Liabilities [Member]apc_AssetRetirementObligationByBalanceSheetLocationAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_AccruedLiabilitiesMemberapc_AssetRetirementObligationByBalanceSheetLocationAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$2falsefalseUSDtruefalse{apc_AssetRetirementObligationByBalanceSheetLocationAxis} : Accrued Liabilities [Member] 12/31/2009 USD ($) $AS_OF_Dec31_2009_apc_AssetRetirementObligationByBalanceSheetLocationAxis_AccruedLiabilitiesMemberhttp://www.sec.gov/CIK0000773910instant2009-12-31T00:00:000001-01-01T00:00:00falsefalseAccrued Liabilities [Member]apc_AssetRetirementObligationByBalanceSheetLocationAxisxbrldihttp://xbrl.org/2006/xbrldius-gaap_AccruedLiabilitiesMemberapc_AssetRetirementObligationByBalanceSheetLocationAxisexplicitMemberUSDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$2false0us-gaap_AssetRetirementObligationCurrentus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse4200000042falsetruefalsefalsefalse2truefalsefalse3100000031falsetruefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryCurrent portion of the carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 143 -Paragraph 3, 10, 22 falsefalseShort-term asset retirement obligations21Asset Retirement Obligations Rollforward (Parenthetical) (Detail) (Accrued Liabilities [Member], USD $)MillionsUnKnownUnKnownUnKnownfalsetrue