Commitments and Contingencies Commitments and Contingencies (Details) - USD ($) $ in Millions		3 Months Ended
	Oct. 25, 2014	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Mr. Icahn and his affiliates [Member]
Loss Contingencies [Line Items]
Affiliate ownership interest		89.10%
ACF [Member]
Loss Contingencies [Line Items]
Defined benefit plan underfunded amount		$ 584		$ 589
Starfire Holding Corporation [Member]
Loss Contingencies [Line Items]
Ownership percentage by Mr. Icahn		99.40%
Net worth floor for which distributions to stockholders would be limited while contingent liabilities exist that can be imposed on us		$ 250
Metals Segment [Member]
Loss Contingencies [Line Items]
Accrued environmental liabilities		28		29
Railcar Segment [Member]
Loss Contingencies [Line Items]
Litigation claim gain amount	$ 25
Litigation counterclaim amount	$ 10
Automotive Segment [Member]
Loss Contingencies [Line Items]
Accrued environmental liabilities		14		14
Possible material additional losses, above and beyond best estimate of required remediation costs		43
Asset retirement obligation		16		16
Energy Segment [Member]
Loss Contingencies [Line Items]
Rent expense on operating leases		2	$ 2
Accrued environmental liabilities		4		4
Environmental remediation expense		4	11
Cost of RINs		43	$ 37
Biofuel blending obligation		$ 24		$ 10
Icahn Enterprises G.P. [Member] | Mr. Icahn and his affiliates [Member]
Loss Contingencies [Line Items]
Affiliate ownership in parent company general partner		100.00%