Income Taxes Narrative (Details) - USD ($) $ in Millions		12 Months Ended
	Aug. 01, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Contingency [Line Items]
Book basis of net assets		$ 6,529	$ 5,106
Book/tax basis difference		(1,940)	(450)
Tax basis of net assets		4,589	4,656
Domestic income (loss) from continuing operations before taxes		290	1,798	$ (2,370)
Foreign income (loss) from continuing operations before taxes		(12)	30	(3)
Income before income tax benefit (expense)		278	1,828	(2,373)
Current income tax (expense) benefit		(15)	(28)	(46)
Deferred income tax (expense) benefit		19	557	134
Income tax benefit (expense)		4	529	88
Deferred tax assets, Property, pland and equipment		17	61
Deferred tax asset, net operating loss		791	711
deferred tax asset, Tax credits		46	71
Deferred Tax Assets, Capital Loss Carryforwards		50	0
Deferred tax asset, Post-employment benefits, including pensions		0	162
Deferred tax asset, Other		82	248
Deferred tax assets, gross		986	1,253
Deferred Tax Assets, Valuation Allowance		518	483
Deferred Tax Assets, Net of Valuation Allowance		468	770
Deferred tax liabilities, Property, plant and equipment		(129)	(235)
Deferred tax liabilities, Intangible assets		(33)	(115)
Deferred tax liability, Investment in partnerships		(681)	(774)
Deferred tax liabilities, Investment in U.S. subsidiaries		(184)	(184)
Deferred tax liabilities, Other		(80)	(119)
Deferred Tax Liabilities, Gross		(1,107)	(1,427)
Deferred tax liabilities, net of deferred tax assets		639	657
Deferred Tax Assets, Net		37	75
Deferred tax liability		676	$ 732
Increase (decrease) in deferred tax asset valuation amount		35
Undistributed earnings of foreign subsidiaries		$ 54
U.S. Federal statutory corporate income tax rate		21.00%	35.00%
Unrecognized tax benefits balance		$ 34	$ 34	52	$ 56
Unrecognized Tax Benefits that Would Impact Effective Tax Rate		30	28	37
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued		1	2	9
Income tax expense related to interest and penalties related to unrecognized tax benefits		(1)	(7)	1
Icahn Enterprises Holdings
Income Tax Contingency [Line Items]
Book basis of net assets		6,557	5,133
Book/tax basis difference		(1,940)	(450)
Tax basis of net assets		4,617	4,683
Income before income tax benefit (expense)		279	1,830	(2,372)
Income tax benefit (expense)		4	529	88
Deferred tax liability		676	732
American Entertainment Properties Corp.
Income Tax Contingency [Line Items]
Deferred tax assets, Operating loss carryforwards, Subject to expiration		2,000
CVR Energy
Income Tax Contingency [Line Items]
Equity issued to acquire additional interest in consolidated subsidiary (number of units)	13,699,549
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit		3
CVR Refining
Income Tax Contingency [Line Items]
Common units validly tendered and not properly withdrawn	21,625,106
Domestic tax authority
Income Tax Contingency [Line Items]
Current income tax (expense) benefit		(11)	(15)	(28)
Deferred income tax (expense) benefit		20	544	131
Foreign tax authority
Income Tax Contingency [Line Items]
Current income tax (expense) benefit		(4)	(13)	(18)
Deferred income tax (expense) benefit		(1)	$ 13	$ 3
Kansas | CVR Energy
Income Tax Contingency [Line Items]
Tax credits		35
United States | Viskase
Income Tax Contingency [Line Items]
Operating loss carryforwards		$ 68
Maximum | United States | American Entertainment Properties Corp.
Income Tax Contingency [Line Items]
Operating Loss Carryforwards, Expiration Date		Dec. 31, 2037
Maximum | Other Foreign countries | Viskase
Income Tax Contingency [Line Items]
Operating loss carryforwards		$ 19
Minimum | Kansas | CVR Energy
Income Tax Contingency [Line Items]
Operating Loss Carryforwards, Expiration Date		Dec. 31, 2033
Minimum | United States | American Entertainment Properties Corp.
Income Tax Contingency [Line Items]
Operating Loss Carryforwards, Expiration Date		Dec. 31, 2029
Minimum | United States | Viskase
Income Tax Contingency [Line Items]
Operating Loss Carryforwards, Expiration Date		Dec. 31, 2024
Minimum | Other Foreign countries | Viskase
Income Tax Contingency [Line Items]
Operating loss carryforwards		$ 5