Commitments and Contingencies - Narrative (Details) - USD ($) $ in Millions			3 Months Ended		6 Months Ended
	Mar. 30, 2022	Jan. 27, 2021	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Starfire Holding Corporation
Loss Contingencies [Line Items]
Ownership percentage by principal owner			99.60%		99.60%
Pension funding indemnity agreement with subsidiary			$ 250.0		$ 250.0
ACF
Loss Contingencies [Line Items]
Funded status of related party pension plan			82.0		$ 82.0
Mr. Icahn and affiliates | Icahn Enterprises G.P.
Loss Contingencies [Line Items]
Affiliate ownership in parent company general partner					100.00%
Mr. Icahn and affiliates | Icahn Enterprises Holdings
Loss Contingencies [Line Items]
Affiliate ownership interest					86.00%
Energy Segment
Loss Contingencies [Line Items]
Environmental loss contingency accrual			24.0		$ 24.0		$ 12.0
Amount of quantifying alleged damages in excess	$ 6.8
Price of RINs			153.0	$ 173.0	259.0	$ 351.0
RFS position			708.0		708.0		494.0
Insurance policies coverage limits		$ 50.0
Energy Segment | Call option lawsuits
Loss Contingencies [Line Items]
Litigation settlement paid					79.0
Accrued expenses and other liabilities
Loss Contingencies [Line Items]
Environmental loss contingency accrual			$ 25.0		25.0		$ 13.0
Accrued expenses and other liabilities | Energy Segment | Call option lawsuits
Loss Contingencies [Line Items]
Litigation settlement paid					$ 79.0