2.2.0.25falsefalse1170 - Disclosure - Asset Retirement Obligationstruefalsefalse1falsefalseUSDfalsefalse1/1/2010 - 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$4false0us-gaap_AssetRetirementObligationDisclosureTextBlockus-gaaptruenadurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse0010.  Asset Retirement Obligations        The majority of Anadarko's AROs relate to the plugging and abandonment of oil and gas properties. The following table provides a rollforward of the Company's combined short and long-term AROs. Liabilities settled include settlement payments for obligations, as well as obligations that were assumed by purchasers of divested properties. Revisions to estimated liabilities during the period relate primarily to changes in estimates of asset retirement costs and include, but are not limited to, revisions of estimated inflation rates, changes in property lives and the expected timing of settling AROs.<div><table style="border-collapse:collapse;margin-top:20px;"><tr style="height: 1px"><td style="width: 530px; text-align:left;border-color:#000000;min-width:530px;"> </td><td style="width: 10px; text-align:left;border-color:#000000;min-width:10px;"> </td><td style="width: 54px; text-align:left;border-color:#000000;min-width:54px;"> </td><td style="width: 10px; text-align:left;border-color:#000000;min-width:10px;"> </td><td style="width: 10px; text-align:left;border-color:#000000;min-width:10px;"> </td><td style="width: 54px; text-align:left;border-color:#000000;min-width:54px;"> </td></tr><tr style="height: 18px"><td style="width: 530px; text-align:left;border-color:#000000;min-width:530px;">millions</td><td colspan="2" style="width: 64px; border-bottom-style:solid;border-bottom-width:1px;text-align:center;border-color:#000000;min-width:64px;">2010</td><td style="width: 10px; text-align:center;border-color:#000000;min-width:10px;"> </td><td colspan="2" style="width: 64px; border-bottom-style:solid;border-bottom-width:1px;text-align:center;border-color:#000000;min-width:64px;">2009</td></tr><tr style="height: 18px"><td style="width: 530px; text-align:left;border-color:#000000;min-width:530px;">Carrying amount of asset retirement obligations at January 1</td><td style="width: 10px; border-top-style:solid;border-top-width:1px;text-align:center;border-color:#000000;min-width:10px;">$</td><td style="width: 54px; border-top-style:solid;border-top-width:1px;text-align:right;border-color:#000000;min-width:54px;">1,446</td><td style="width: 10px; text-align:left;border-color:#000000;min-width:10px;"> </td><td style="width: 10px; border-top-style:solid;border-top-width:1px;text-align:center;border-color:#000000;min-width:10px;">$</td><td style="width: 54px; border-top-style:solid;border-top-width:1px;text-align:right;border-color:#000000;min-width:54px;">1,368</td></tr><tr style="height: 18px"><td style="width: 530px; text-align:left;border-color:#000000;min-width:530px;">Liabilities incurred</td><td style="width: 10px; text-align:center;border-color:#000000;min-width:10px;"> </td><td style="width: 54px; text-align:right;border-color:#000000;min-width:54px;">88</td><td style="width: 10px; text-align:left;border-color:#000000;min-width:10px;"> </td><td style="width: 10px; text-align:center;border-color:#000000;min-width:10px;"> </td><td style="width: 54px; text-align:right;border-color:#000000;min-width:54px;">46</td></tr><tr style="height: 18px"><td style="width: 530px; text-align:left;border-color:#000000;min-width:530px;">Liabilities settled</td><td style="width: 10px; text-align:center;border-color:#000000;min-width:10px;"> </td><td style="width: 54px; text-align:right;border-color:#000000;min-width:54px;">(36)</td><td style="width: 10px; text-align:left;border-color:#000000;min-width:10px;"> </td><td style="width: 10px; text-align:center;border-color:#000000;min-width:10px;"> </td><td style="width: 54px; text-align:right;border-color:#000000;min-width:54px;">(54)</td></tr><tr style="height: 18px"><td style="width: 530px; text-align:left;border-color:#000000;min-width:530px;">Accretion expense</td><td style="width: 10px; text-align:center;border-color:#000000;min-width:10px;"> </td><td style="width: 54px; text-align:right;border-color:#000000;min-width:54px;">92</td><td style="width: 10px; text-align:left;border-color:#000000;min-width:10px;"> </td><td style="width: 10px; text-align:center;border-color:#000000;min-width:10px;"> </td><td style="width: 54px; text-align:right;border-color:#000000;min-width:54px;">89</td></tr><tr style="height: 18px"><td style="width: 530px; text-align:left;border-color:#000000;min-width:530px;">Revisions in estimated liabilities</td><td style="width: 10px; border-bottom-style:solid;border-bottom-width:1px;text-align:center;border-color:#000000;min-width:10px;"> </td><td style="width: 54px; border-bottom-style:solid;border-bottom-width:1px;text-align:right;border-color:#000000;min-width:54px;">(19)</td><td style="width: 10px; text-align:left;border-color:#000000;min-width:10px;"> </td><td style="width: 10px; border-bottom-style:solid;border-bottom-width:1px;text-align:center;border-color:#000000;min-width:10px;"> </td><td style="width: 54px; border-bottom-style:solid;border-bottom-width:1px;text-align:right;border-color:#000000;min-width:54px;">(3)</td></tr><tr style="height: 18px"><td style="width: 530px; text-align:left;border-color:#000000;min-width:530px;">Carrying amount of asset retirement obligations at December 31 (1)</td><td style="width: 10px; border-top-style:solid;border-top-width:1px;border-bottom-style:solid;border-bottom-width:1px;text-align:center;border-color:#000000;min-width:10px;">$</td><td style="width: 54px; border-top-style:solid;border-top-width:1px;border-bottom-style:solid;border-bottom-width:1px;text-align:right;border-color:#000000;min-width:54px;">1,571</td><td style="width: 10px; text-align:left;border-color:#000000;min-width:10px;"> </td><td style="width: 10px; border-top-style:solid;border-top-width:1px;border-bottom-style:solid;border-bottom-width:1px;text-align:center;border-color:#000000;min-width:10px;">$</td><td style="width: 54px; border-top-style:solid;border-top-width:1px;border-bottom-style:solid;border-bottom-width:1px;text-align:right;border-color:#000000;min-width:54px;">1,446</td></tr><tr style="height: 1px"><td style="width: 530px; text-align:left;border-color:#000000;min-width:530px;"> </td><td style="width: 10px; border-top-style:solid;border-top-width:1px;text-align:left;border-color:#000000;min-width:10px;"> </td><td style="width: 54px; border-top-style:solid;border-top-width:1px;text-align:left;border-color:#000000;min-width:54px;"> </td><td style="width: 10px; text-align:left;border-color:#000000;min-width:10px;"> </td><td style="width: 10px; border-top-style:solid;border-top-width:1px;text-align:left;border-color:#000000;min-width:10px;"> </td><td style="width: 54px; border-top-style:solid;border-top-width:1px;text-align:left;border-color:#000000;min-width:54px;"> </td></tr></table></div>_________________________________________________________(1)  At December 31, 2010 and 2009, short-term AROs of $42 million and $31 million, respectively, were presented in the Consolidated Balance Sheets as accrued expenses.10.  Asset Retirement Obligations        The majority of Anadarko's AROs relate to the plugging andfalsefalsefalsefalsefalseOtherus-types:textBlockItemTypestringDescription of the asset retirement obligation and the associated long-lived asset. An asset retirement obligation is a legal obligation associated with the disposal or retirement from service 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. This element may be used for all the disclosures related to asset retirement obligations.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 143 -Paragraph 22 falsefalseAsset Retirement Obligations11Asset Retirement ObligationsUnKnownUnKnownUnKnownUnKnownfalsetrue