Increase Decrease Related Party Transaction Amounts

No definition available.

Name:	iep_IncreaseDecreaseRelatedPartyTransactionAmounts
Namespace Prefix:	iep_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

investment in nonconsolidated VIE

+ References

No definition available.

+ Details

Name:	iep_InvestmentinnonconsolidatedVIE
Namespace Prefix:	iep_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

investment in related parties

+ References

No definition available.

+ Details

Name:	iep_Investmentinrelatedparties
Namespace Prefix:	iep_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Percentage fair value of investments in Funds that is attributable to Mr. Icahn

+ References

No definition available.

+ Details

Name:	iep_PercentagefairvalueofinvestmentsinFundsthatisattributabletoMr.Icahn
Namespace Prefix:	iep_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Variable Interest Entities Equity Earnings

+ References

No definition available.

+ Details

Name:	iep_VariableInterestEntitiesEquityEarnings
Namespace Prefix:	iep_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Variable Interest Entity, Nonconsolidated, assets at VIE

+ References

No definition available.

+ Details

Name:	iep_VariableInterestEntityNonconsolidatedassetsatVIE
Namespace Prefix:	iep_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Variable Interest Entity, Nonconsolidated, liabilities at VIE

+ References

No definition available.

+ Details

Name:	iep_VariableInterestEntityNonconsolidatedliabilitiesatVIE
Namespace Prefix:	iep_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Portion of equity (net assets) in a variable interest entity (VIE) not attributable, directly or indirectly, to the parent entity. That is, this is the portion of equity in a VIE that is attributable to the noncontrolling interest (previously referred to as minority interest).

+ References

No definition available.

+ Details

Name:	us-gaap_NoncontrollingInterestInVariableInterestEntity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of transactions with related party during the financial reporting period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39622-107864

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39603-107864

+ Details

Name:	us-gaap_RelatedPartyTransactionAmountsOfTransaction
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_RelatedPartyTransactionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=iep_PrincipalOwnersAndAffiliatesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=iep_InvestmentinfundsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=iep_ConsolidatedVIEMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=iep_ExpenseSharingAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=us-gaap_EquityMethodInvesteeMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=sic_Z7600
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=iep_InsightPortfolioGroupLLCMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=us-gaap_OperatingExpenseMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=iep_A767LeasingMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementBusinessSegmentsAxis=iep_AutomotiveSegmentMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Related Party Transactions (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Mr. Icahn and affiliates \| Investment in funds
Related Party Transaction [Line Items]
Amount of transaction with related party	$ 1,241
Related party transaction, balance	$ 4,900		$ 4,500
Percentage fair value of investments in Funds that is attributable to Mr. Icahn	53.00%		51.00%
Consolidated VIE \| Expense sharing arrangement
Related Party Transaction [Line Items]
Amount of transaction with related party	$ (6)	$ 3
Reduction in amount of transaction with related party	8
Hertz (equity method investee) \| Receipts and revenue from related party
Related Party Transaction [Line Items]
Amount of transaction with related party	14	12
Insight Portfolio Group LLC \| Buying group operating expenses
Related Party Transaction [Line Items]
Amount of transaction with related party		1
767 Leasing \| Automotive Segment
Related Party Transaction [Line Items]
Assets at non-consolidated VIE	120		$ 121
Liabilities at non-consolidated VIE	0		$ 1
VIE equity earnings	0	2
Investment in non-consolidated VIE during the period		$ 25
Investment balance in non-consolidated VIE as of end of period period	$ 120