Basis of Presentation and Summary of Significant Accounting Policies Variable Interest Entities (Details) - Icahn Enterprises Holdings - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Percentage of equity ownership in operating subsidiary	99.00%
Cash and cash equivalents
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Assets of VIE's	$ 223	$ 370
Property, plant and equipment
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Assets of VIE's	3,191	3,331
Inventories
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Assets of VIE's	385	349
Intangible assets, net
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Assets of VIE's	298	318
Other assets
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Assets of VIE's	48	110
Accounts payable, accrued expenses and other liabilities
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Liabilities of VIE's	1,816	1,769
Debt
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Liabilities of VIE's	1,166	1,165
Cash held at consolidated affiliated partnerships and restricted cash
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Assets of VIE's	734	752
Investments
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Assets of VIE's	9,615	9,219
Due from broker
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Assets of VIE's	506	1,482
Securities Sold, Not yet Purchased
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Liabilities of VIE's	1,023	1,139
Due to brokers
Organization, Consolidation and Presentation of Financial Statements [Line Items]
Liabilities of VIE's	$ 1,057	$ 3,725

[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://www.xbrl.org/2003/role/presentationRef
-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://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 810
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (bb)
-URI http://asc.fasb.org/extlink&oid=77990344&loc=d3e5710-111685

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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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