XML 54 R62.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Fair Value Measurements Other Segments Fair Value (Details) (USD $) | Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012
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Other Segments and Holding Company [Member] | Recurring measurement [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Marketable equity and debt securities | $ 153,000,000 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember |  | $ 1,000,000 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember |  |
Trading securities | 55,000,000 us-gaap_TradingSecurities / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember |  | 116,000,000 us-gaap_TradingSecurities / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember |  |
Derivative contracts, Assets at fair value | 47,000,000 us-gaap_DerivativeAssets / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember | [1] | 1,000,000 us-gaap_DerivativeAssets / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember | [1] |
Fair value of investment and derivative assets | 255,000,000 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember |  | 118,000,000 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember |  |
Liabilities [Abstract] |  |  |  |  |
Other liabilities | 50,000,000 us-gaap_OtherLiabilities / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember | [2] | 16,000,000 us-gaap_OtherLiabilities / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember | [2] |
Derivative contracts, Liabilities at fair value | 2,000,000 us-gaap_DerivativeLiabilities / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember | [2] | 35,000,000 us-gaap_DerivativeLiabilities / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember | [2] |
Fair value of investment and derivative liabilities | 52,000,000 us-gaap_LiabilitiesFairValueDisclosure / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember |  | 51,000,000 us-gaap_LiabilitiesFairValueDisclosure / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember |  |
Other Segments and Holding Company [Member] | Recurring measurement [Member] | Level 1 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Marketable equity and debt securities | 75,000,000 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember |  | 1,000,000 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember |  |
Trading securities | 0 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember |  | 0 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember |  |
Derivative contracts, Assets at fair value | 0 us-gaap_DerivativeAssets / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember | [1] | 0 us-gaap_DerivativeAssets / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember | [1] |
Fair value of investment and derivative assets | 75,000,000 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember |  | 1,000,000 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember |  |
Liabilities [Abstract] |  |  |  |  |
Other liabilities | 0 us-gaap_OtherLiabilities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember | [2] | 0 us-gaap_OtherLiabilities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember | [2] |
Derivative contracts, Liabilities at fair value | 0 us-gaap_DerivativeLiabilities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember | [2] | 0 us-gaap_DerivativeLiabilities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember | [2] |
Fair value of investment and derivative liabilities | 0 us-gaap_LiabilitiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember |  | 0 us-gaap_LiabilitiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember |  |
Other Segments and Holding Company [Member] | Recurring measurement [Member] | Level 2 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Marketable equity and debt securities | 3,000,000 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember |  | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember |  |
Trading securities | 0 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember |  | 0 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember |  |
Derivative contracts, Assets at fair value | 47,000,000 us-gaap_DerivativeAssets / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember | [1] | 1,000,000 us-gaap_DerivativeAssets / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember | [1] |
Fair value of investment and derivative assets | 50,000,000 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember |  | 1,000,000 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember |  |
Liabilities [Abstract] |  |  |  |  |
Other liabilities | 50,000,000 us-gaap_OtherLiabilities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember | [2] | 16,000,000 us-gaap_OtherLiabilities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember | [2] |
Derivative contracts, Liabilities at fair value | 2,000,000 us-gaap_DerivativeLiabilities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember | [2] | 35,000,000 us-gaap_DerivativeLiabilities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember | [2] |
Fair value of investment and derivative liabilities | 52,000,000 us-gaap_LiabilitiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember |  | 51,000,000 us-gaap_LiabilitiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember |  |
Other Segments and Holding Company [Member] | Recurring measurement [Member] | Level 3 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Marketable equity and debt securities | 75,000,000 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember |  | 0 us-gaap_AvailableForSaleSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember |  |
Trading securities | 55,000,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember |  | 116,000,000 us-gaap_TradingSecurities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember |  |
Derivative contracts, Assets at fair value | 0 us-gaap_DerivativeAssets / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember | [1] | 0 us-gaap_DerivativeAssets / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember | [1] |
Fair value of investment and derivative assets | 130,000,000 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember |  | 116,000,000 us-gaap_AssetsFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember |  |
Liabilities [Abstract] |  |  |  |  |
Other liabilities | 0 us-gaap_OtherLiabilities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember | [2] | 0 us-gaap_OtherLiabilities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember | [2] |
Derivative contracts, Liabilities at fair value | 0 us-gaap_DerivativeLiabilities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember | [2] | 0 us-gaap_DerivativeLiabilities / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember | [2] |
Fair value of investment and derivative liabilities | 0 us-gaap_LiabilitiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember |  | 0 us-gaap_LiabilitiesFairValueDisclosure / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_OtherSegmentsAndHoldingCompanyMember |  |
Railcar and Food Packaging [Member] | Recurring measurement [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 139,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_RailcarAndFoodPackagingMember |  | 135,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_RailcarAndFoodPackagingMember |  |
Railcar and Food Packaging [Member] | Recurring measurement [Member] | Level 1 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 88,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_RailcarAndFoodPackagingMember |  | 97,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_RailcarAndFoodPackagingMember |  |
Railcar and Food Packaging [Member] | Recurring measurement [Member] | Level 2 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 30,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_RailcarAndFoodPackagingMember |  | 17,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_RailcarAndFoodPackagingMember |  |
Railcar and Food Packaging [Member] | Recurring measurement [Member] | Level 3 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 21,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_RailcarAndFoodPackagingMember |  | 21,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_RailcarAndFoodPackagingMember |  |
United States Plans | Automotive Segment [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 912,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 909,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 778,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember
United States Plans | Automotive Segment [Member] | Recurring measurement [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 912,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 909,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
United States Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 1 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 796,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 794,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
United States Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 2 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 25,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 30,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
United States Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 3 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 91,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 85,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Non-U.S. Plans | Automotive Segment [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 54,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 55,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 55,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember
Non-U.S. Plans | Automotive Segment [Member] | Recurring measurement [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 54,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 55,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Non-U.S. Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 1 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 11,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 9,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Non-U.S. Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 2 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 2,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 2,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Non-U.S. Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 3 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 41,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 44,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Cash | Railcar and Food Packaging [Member] | Recurring measurement [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 6,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CashAndCashEquivalentsMember / us-gaap_StatementBusinessSegmentsAxis = iep_RailcarAndFoodPackagingMember |  | 5,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CashAndCashEquivalentsMember / us-gaap_StatementBusinessSegmentsAxis = iep_RailcarAndFoodPackagingMember |  |
Cash | Railcar and Food Packaging [Member] | Recurring measurement [Member] | Level 1 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 5,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CashAndCashEquivalentsMember / us-gaap_StatementBusinessSegmentsAxis = iep_RailcarAndFoodPackagingMember |  | 4,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CashAndCashEquivalentsMember / us-gaap_StatementBusinessSegmentsAxis = iep_RailcarAndFoodPackagingMember |  |
Cash | Railcar and Food Packaging [Member] | Recurring measurement [Member] | Level 2 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 1,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CashAndCashEquivalentsMember / us-gaap_StatementBusinessSegmentsAxis = iep_RailcarAndFoodPackagingMember |  | 1,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CashAndCashEquivalentsMember / us-gaap_StatementBusinessSegmentsAxis = iep_RailcarAndFoodPackagingMember |  |
Cash | Railcar and Food Packaging [Member] | Recurring measurement [Member] | Level 3 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CashAndCashEquivalentsMember / us-gaap_StatementBusinessSegmentsAxis = iep_RailcarAndFoodPackagingMember |  | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CashAndCashEquivalentsMember / us-gaap_StatementBusinessSegmentsAxis = iep_RailcarAndFoodPackagingMember |  |
Cash | United States Plans | Automotive Segment [Member] | Recurring measurement [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 44,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CashAndCashEquivalentsMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 33,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CashAndCashEquivalentsMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Cash | United States Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 1 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 44,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CashAndCashEquivalentsMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 33,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CashAndCashEquivalentsMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Cash | United States Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 2 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CashAndCashEquivalentsMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CashAndCashEquivalentsMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Cash | United States Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 3 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CashAndCashEquivalentsMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CashAndCashEquivalentsMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Equity securities | United States Plans | Automotive Segment [Member] | Recurring measurement [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 314,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_EquityFundsMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 347,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_EquityFundsMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Equity securities | United States Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 1 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 314,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_EquityFundsMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 347,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_EquityFundsMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Equity securities | United States Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 2 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_EquityFundsMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_EquityFundsMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Equity securities | United States Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 3 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_EquityFundsMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_EquityFundsMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Fixed income securities | Railcar and Food Packaging [Member] | Recurring measurement [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 23,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_RailcarAndFoodPackagingMember |  | 22,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_RailcarAndFoodPackagingMember |  |
Fixed income securities | Railcar and Food Packaging [Member] | Recurring measurement [Member] | Level 1 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 22,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_RailcarAndFoodPackagingMember |  | 21,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_RailcarAndFoodPackagingMember |  |
Fixed income securities | Railcar and Food Packaging [Member] | Recurring measurement [Member] | Level 2 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 1,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_RailcarAndFoodPackagingMember |  | 1,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_RailcarAndFoodPackagingMember |  |
Fixed income securities | Railcar and Food Packaging [Member] | Recurring measurement [Member] | Level 3 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_RailcarAndFoodPackagingMember |  | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_RailcarAndFoodPackagingMember |  |
Fixed income securities | United States Plans | Automotive Segment [Member] | Recurring measurement [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 166,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 135,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Fixed income securities | United States Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 1 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 166,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 135,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Fixed income securities | United States Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 2 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Fixed income securities | United States Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 3 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Fixed income securities | Non-U.S. Plans | Automotive Segment [Member] | Recurring measurement [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 10,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 7,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Fixed income securities | Non-U.S. Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 1 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 10,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 7,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Fixed income securities | Non-U.S. Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 2 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Fixed income securities | Non-U.S. Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 3 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_FixedIncomeSecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Real estate and other | United States Plans | Automotive Segment [Member] | Recurring measurement [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 25,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = iep_RealEstateAndOtherMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 23,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = iep_RealEstateAndOtherMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Real estate and other | United States Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 1 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 25,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = iep_RealEstateAndOtherMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 23,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = iep_RealEstateAndOtherMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Real estate and other | United States Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 2 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = iep_RealEstateAndOtherMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = iep_RealEstateAndOtherMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Real estate and other | United States Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 3 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = iep_RealEstateAndOtherMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = iep_RealEstateAndOtherMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Equity securities | Railcar and Food Packaging [Member] | Recurring measurement [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 83,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_EquitySecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_RailcarAndFoodPackagingMember |  | 81,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_EquitySecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_RailcarAndFoodPackagingMember |  |
Equity securities | Railcar and Food Packaging [Member] | Recurring measurement [Member] | Level 1 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 55,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_EquitySecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_RailcarAndFoodPackagingMember |  | 66,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_EquitySecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_RailcarAndFoodPackagingMember |  |
Equity securities | Railcar and Food Packaging [Member] | Recurring measurement [Member] | Level 2 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 28,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_EquitySecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_RailcarAndFoodPackagingMember |  | 15,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_EquitySecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_RailcarAndFoodPackagingMember |  |
Equity securities | Railcar and Food Packaging [Member] | Recurring measurement [Member] | Level 3 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_EquitySecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_RailcarAndFoodPackagingMember |  | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_EquitySecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_RailcarAndFoodPackagingMember |  |
Equity securities | United States Plans | Automotive Segment [Member] | Recurring measurement [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 231,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_EquitySecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 242,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_EquitySecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Equity securities | United States Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 1 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 231,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_EquitySecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 242,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_EquitySecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Equity securities | United States Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 2 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_EquitySecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_EquitySecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Equity securities | United States Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 3 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_EquitySecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_EquitySecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Equity securities | Non-U.S. Plans | Automotive Segment [Member] | Recurring measurement [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 1,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_EquitySecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 2,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_EquitySecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Equity securities | Non-U.S. Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 1 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 1,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_EquitySecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 2,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_EquitySecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Equity securities | Non-U.S. Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 2 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_EquitySecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_EquitySecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Equity securities | Non-U.S. Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 3 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_EquitySecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_EquitySecuritiesMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Fixed income collective trust | United States Plans | Automotive Segment [Member] | Recurring measurement [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = iep_FixedIncomeCollectiveTrustMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = iep_FixedIncomeCollectiveTrustMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Fixed income collective trust | United States Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 1 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = iep_FixedIncomeCollectiveTrustMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = iep_FixedIncomeCollectiveTrustMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Fixed income collective trust | United States Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 2 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = iep_FixedIncomeCollectiveTrustMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = iep_FixedIncomeCollectiveTrustMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Fixed income collective trust | United States Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 3 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = iep_FixedIncomeCollectiveTrustMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = iep_FixedIncomeCollectiveTrustMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Corporate and other | United States Plans | Automotive Segment [Member] | Recurring measurement [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 21,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateAndOtherMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 22,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateAndOtherMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Corporate and other | United States Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 1 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateAndOtherMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateAndOtherMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Corporate and other | United States Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 2 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 21,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateAndOtherMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 22,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateAndOtherMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Corporate and other | United States Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 3 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateAndOtherMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_CorporateAndOtherMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Government | United States Plans | Automotive Segment [Member] | Recurring measurement [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 20,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_GovernmentMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 22,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_GovernmentMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Government | United States Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 1 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 16,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_GovernmentMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 14,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_GovernmentMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Government | United States Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 2 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 4,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_GovernmentMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 8,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_GovernmentMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Government | United States Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 3 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_GovernmentMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_GovernmentMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Hedge funds | United States Plans | Automotive Segment [Member] | Recurring measurement [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 91,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_HedgeFundsMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 85,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_HedgeFundsMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Hedge funds | United States Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 1 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_HedgeFundsMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_HedgeFundsMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Hedge funds | United States Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 2 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_HedgeFundsMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel2Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_HedgeFundsMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Hedge funds | United States Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 3 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 91,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_HedgeFundsMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 85,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_UnitedStatesPensionPlansOfUSEntityDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel3Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = us-gaap_HedgeFundsMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Insurance contracts | Non-U.S. Plans | Automotive Segment [Member] | Recurring measurement [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 41,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = iep_InsuranceContractsMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 44,000,000 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = iep_InsuranceContractsMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Insurance contracts | Non-U.S. Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 1 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
Defined Benefit Plan, Fair Value of Plan Assets | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = iep_InsuranceContractsMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  | 0 us-gaap_DefinedBenefitPlanFairValueOfPlanAssets / us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis = us-gaap_ForeignPensionPlansDefinedBenefitMember / us-gaap_FairValueByFairValueHierarchyLevelAxis = us-gaap_FairValueInputsLevel1Member / us-gaap_FairValueByMeasurementFrequencyAxis = us-gaap_FairValueMeasurementsRecurringMember / us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis = iep_InsuranceContractsMember / us-gaap_StatementBusinessSegmentsAxis = iep_AutomotiveSegmentMember |  |
Insurance contracts | Non-U.S. Plans | Automotive Segment [Member] | Recurring measurement [Member] | Level 2 [Member] |  |  |  |  |
Assets [Abstract] |  |  |  |  |
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[1] | Amounts are classified within other assets in our consolidated balance sheets.
[2] | Amounts are classified within accrued expenses and other liabilities in our consolidated balance sheets.

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