Basis of Presentation and Summary of Significant Accounting Policies Variable Interest Entities (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Icahn Enterprises Holdings
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Percentage of equity ownership in operating subsidiary	99.00%
Icahn Enterprises Holdings \| Cash and cash equivalents
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Assets of VIE's	$ 415	$ 223
Icahn Enterprises Holdings \| Cash held at consolidated affiliated partnerships and restricted cash
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Assets of VIE's	2,648	734
Icahn Enterprises Holdings \| Investments
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Assets of VIE's	6,951	9,615
Icahn Enterprises Holdings \| Due from brokers
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Assets of VIE's	664	506
Icahn Enterprises Holdings \| Property, plant and equipment
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Assets of VIE's	3,027	3,185
Icahn Enterprises Holdings \| Inventories
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Assets of VIE's	380	369
Icahn Enterprises Holdings \| Intangible assets, net
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Assets of VIE's	278	298
Icahn Enterprises Holdings \| Other assets
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Assets of VIE's	863	267
Icahn Enterprises Holdings \| Accounts payable, accrued expenses and other liabilities
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Liabilities of VIE's	516	1,815
Icahn Enterprises Holdings \| Securities Sold, Not yet Purchased
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Liabilities of VIE's	468	1,023
Icahn Enterprises Holdings \| Due to brokers
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Liabilities of VIE's	141	1,057
Icahn Enterprises Holdings \| Debt
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Liabilities of VIE's	$ 1,170	$ 1,166
Viskase
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Subsidiary ownership interest in variable interest entity	50.00%

[Line Items] for Organization, Consolidation and Presentation of Financial Statements [Table]

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- Definition

The number of units or percentage investment held in the subsidiary by the limited liability company or limited partnership.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 320
-Section S99
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=50485924&loc=d3e611443-123010

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- Definition

The carrying amount of the consolidated Variable Interest Entity's assets included in the reporting entity's statement of financial position.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (bb)
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The carrying amount of the consolidated Variable Interest Entity's liabilities included in the reporting entity's statement of financial position.

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- Definition

Percentage of the Variable Interest Entity's (VIE) voting interest owned by (or beneficial interest in) the reporting entity (directly or indirectly).

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-Publisher FASB
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-Topic 810
-SubTopic 10
-Section 50
-Paragraph 5A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=108788376&loc=SL6759159-111685

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