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falsefalseContributions to the Company's funded pension plans6false0apc_UnfundedPensionContributionsapcfalsecreditdurationThe amount of cash or cash equivalents contributed by the entity to fund its unfunded pension plans.falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse1100000011000000falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe amount of cash or cash equivalents contributed by the entity to fund its unfunded pension plans.No authoritative reference available.falsefalseContributions to the Company's unfunded pension plans7false0us-gaap_OtherPostretirementBenefitsPaymentsus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse1700000017000000falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe amount of cash or cash equivalents contributed during the reporting period by the entity to fund non-pension postretirement benefits.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 falsefalseContributions to the Company's unfunded other postretirement benefit plans8false0apc_ExpectedPensionContributionsapcfalsecreditdurationThe amount of cash or cash equivalents expected to be contributed by the entity to fund its pension plans by the end of the...falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse234000000234000000falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe amount of cash or cash equivalents expected to be contributed by the entity to fund its pension plans by the end of the next fiscal year.No authoritative reference available.falsefalseExpected contributions to the Company's funded pension plans in 20119false0apc_ExpectedUnfundedPensionContributionsapcfalsecreditdurationThe amount of cash or cash equivalents expected to be contributed by the entity to fund its unfunded pension plans by the end...falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse2900000029000000falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe amount of cash or cash equivalents expected to be contributed by the entity to fund its unfunded pension plans by the end of the next fiscal year.No authoritative reference available.falsefalseExpected contributions to the Company's unfunded pension plans in 201110false0apc_ExpectedOtherPostretirementBenefitsPaymentsapcfalsecreditdurationThe amount of cash or cash equivalents expected to be contributed during the reporting period by the entity to fund...falsefalsefalsefalsefalsefalsefalsefalsefalsefalseverboselabel1truefalsefalse1800000018000000falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe amount of cash or cash equivalents expected to be contributed during the reporting period by the entity to fund non-pension postretirement benefits by the end of the next fiscal year.No authoritative reference available.falsefalseExpected contributions to the Company's unfunded other postretirement benefit plans in 201111false0us-gaap_DefinedBenefitPlanAccumulatedBenefitObligationus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse17000000001700000000falsefalsefalsefalsefalse2truefalsefalse15000000001500000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryFor defined benefit pension plans, the actuarial present value of benefits (whether vested or nonvested) attributed by the pension benefit formula to employee service rendered before a specified date and based on employee service and compensation (if applicable) before that date. The accumulated benefit obligation differs from the projected benefit obligation in that it includes no assumption about future compensation levels. For plans with flat-benefit or nonpay-related pension benefit formulas, the accumulated benefit obligation and the projected benefit obligation are the same.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph e falsefalseDefined benefit plan accumulated benefit obligation12false0us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateProjectedBenefitObligationus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse18000000001800000000falsefalsefalsefalsefalse2truefalsefalse16000000001600000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryIf aggregate disclosures are presented, the aggregate projected benefit obligation for pension plans with accumulated benefit obligations in excess of plan assets as of the measurement date of each statement of financial position presented.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph C3 falsefalseDefined benefit plan pension plans with accumulated benefit obligations in excess of plan assets aggregate projected benefit obligation13false0us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligationus-gaaptruecreditinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse16000000001600000000falsefalsefalsefalsefalse2truefalsefalse14000000001400000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryIf aggregate disclosures are presented, the aggregate pension accumulated benefit obligation for pension plans with accumulated benefit obligations in excess of plan assets as of the measurement date of each statement of financial position presented.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 6 -Subparagraph b falsefalseDefined benefit plan pension plans with accumulated benefit obligations in excess of plan assets aggregate accumulated benefit obligation14false0us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssetsus-gaaptruedebitinstantNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse10000000001000000000falsefalsefalsefalsefalse2truefalsefalse897000000897000000falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryIf aggregate disclosures are presented, the aggregate fair value of plan assets for pension plans with accumulated benefit obligations in excess of plan assets as of the measurement date of each statement of financial position presented.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 6 -Subparagraph b falsefalseDefined benefit plan pension plans with accumulated benefit obligations in excess of plan assets aggregate fair value of plan assets15false0us-gaap_DefinedBenefitPlanAmountsThatWillBeAmortizedFromAccumulatedOtherComprehensiveIncomeLossInNextFiscalYearus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse8600000086000000falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe aggregate amount in accumulated other comprehensive income expected to be recognized as a component of net periodic benefit cost over the fiscal year that follows the most recent annual statement of financial position presented (including the net gain or loss, net prior service cost or credit, and net transition asset or obligation).Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph s Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 158 -Paragraph 7 -Subparagraph d falsefalseDefined benefit plan amounts that will be amortized from accumulated other comprehensive income loss in next fiscal year16false0us-gaap_DefinedBenefitPlanAmortizationOfNetGainsLossesus-gaaptruedebitdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsetruenegated1truefalsefalse8500000085000000falsefalsefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe amounts in accumulated other comprehensive income related to gains and losses that are not recognized immediately and are expected to be recognized as components of net periodic benefit cost over the next fiscal year that follows the most recent annual statement of financial position presented.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph s Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 158 -Paragraph 7 -Subparagraph d falsefalseDefined benefit plan amortization of net gains losses17false0us-gaap_DefinedBenefitPlanAmortizationOfNetPriorServiceCostCreditus-gaaptruecreditdurationNo definition available.falsefalsefalsefalsefalsefalsefalsefalsefalsefalse1truefalsefalse10000001000000falsetruefalsefalsefalse2falsefalsefalse00falsefalsefalsefalsefalseMonetaryxbrli:monetaryItemTypemonetaryThe amounts in accumulated other comprehensive income related to prior service cost or credit expected to be recognized as components of net periodic benefit cost over the next fiscal year that follows the most recent annual statement of financial position presented.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 132R -Paragraph 5 -Subparagraph s Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 158 -Paragraph 7 -Subparagraph d falsefalseDefined benefit plan amortization of net prior service cost credit213Pension Plans, Other Postretirement Benefits and Defined Contribution Plans - Additional Information (Detail) (USD $)NoRoundingUnKnownUnKnownUnKnownfalsetrue