Discontinued Operations Income From Discontinued Operations (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
(Loss) income from discontinued operations	$ (8)	$ 0	$ (24)	$ 0	$ 1,376	$ 176	$ 167	$ 45	$ (32)	$ 1,764	$ 234
(Loss) income from discontinued operations attributable to Icahn Enterprises									(32)	1,720	157
Discontinued operations and held for sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net sales									0	6,221	7,985
Other revenues from operations									0	892	1,095
Interest and dividend income									0	5	9
Gain (loss) on disposition of assets, net									0	65	6
Other income, net									0	19	61
Revenue									0	7,202	9,158
Cost of goods sold									0	5,214	6,802
Other expenses from operations									0	425	525
Selling, general and administrative									0	879	1,270
Restructuring, net									0	13	21
Impairment									0	6	25
Interest expense									0	160	187
Costs and expenses									0	6,697	8,830
Income (loss) from discontinued operations before gain (loss) on sale and income tax (expense) benefit									0	505	328
Gain (loss) on sale of discontinued operations									0	1,430	(3)
Income (loss) from discontinued operations before income tax (expense) benefit									0	1,935	325
Income tax (expense) benefit									(32)	(171)	(91)
(Loss) income from discontinued operations									(32)	1,764	234
Less: income from discontinued operations attributable to non-controlling interests									0	44	77
(Loss) income from discontinued operations attributable to Icahn Enterprises									(32)	1,720	157
Capital expenditures									0	486	676
Depreciation and amortization									0	166	528
Disposal group, including discontinued operation, net gains (losses) on investment activities									0	0	2
Federal-Mogul | Discontinued operations and held for sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net sales									0	5,993	7,720
Other revenues from operations									0	0	0
Interest and dividend income									0	2	6
Gain (loss) on disposition of assets, net									0	65	7
Other income, net									0	5	31
Revenue									0	6,065	7,764
Cost of goods sold									0	4,999	6,553
Other expenses from operations									0	0	0
Selling, general and administrative									0	601	862
Restructuring, net									0	13	21
Impairment									0	2	25
Interest expense									0	137	154
Costs and expenses									0	5,752	7,615
Income (loss) from discontinued operations before gain (loss) on sale and income tax (expense) benefit									0	313	149
Gain (loss) on sale of discontinued operations									0	251	0
Income (loss) from discontinued operations before income tax (expense) benefit									0	564	149
Income tax (expense) benefit									(32)	(69)	(33)
(Loss) income from discontinued operations									(32)	495	116
Less: income from discontinued operations attributable to non-controlling interests									0	7	11
(Loss) income from discontinued operations attributable to Icahn Enterprises									(32)	488	105
Capital expenditures									0	303	393
Depreciation and amortization									0	100	397
Disposal group, including discontinued operation, net gains (losses) on investment activities									0	0	0
Tropicana | Discontinued operations and held for sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net sales									0	0	0
Other revenues from operations									0	679	898
Interest and dividend income									0	1	1
Gain (loss) on disposition of assets, net									0	0	(1)
Other income, net									0	1	27
Revenue									0	681	925
Cost of goods sold									0	0	0
Other expenses from operations									0	311	425
Selling, general and administrative									0	238	371
Restructuring, net									0	0	0
Impairment									0	0	0
Interest expense									0	4	11
Costs and expenses									0	553	807
Income (loss) from discontinued operations before gain (loss) on sale and income tax (expense) benefit									0	128	118
Gain (loss) on sale of discontinued operations									0	779	(3)
Income (loss) from discontinued operations before income tax (expense) benefit									0	907	115
Income tax (expense) benefit									0	(89)	(93)
(Loss) income from discontinued operations									0	818	22
Less: income from discontinued operations attributable to non-controlling interests									0	17	13
(Loss) income from discontinued operations attributable to Icahn Enterprises									0	801	9
Capital expenditures									0	58	112
Depreciation and amortization									0	19	73
Disposal group, including discontinued operation, net gains (losses) on investment activities									0	0	0
American Railcar Industries | Discontinued operations and held for sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net sales									0	228	265
Other revenues from operations									0	213	197
Interest and dividend income									0	2	2
Gain (loss) on disposition of assets, net									0	0	0
Other income, net									0	13	3
Revenue									0	456	469
Cost of goods sold									0	215	249
Other expenses from operations									0	114	100
Selling, general and administrative									0	40	37
Restructuring, net									0	0	0
Impairment									0	4	0
Interest expense									0	19	22
Costs and expenses									0	392	408
Income (loss) from discontinued operations before gain (loss) on sale and income tax (expense) benefit									0	64	61
Gain (loss) on sale of discontinued operations									0	400	0
Income (loss) from discontinued operations before income tax (expense) benefit									0	464	61
Income tax (expense) benefit									0	(13)	35
(Loss) income from discontinued operations									0	451	96
Less: income from discontinued operations attributable to non-controlling interests									0	20	53
(Loss) income from discontinued operations attributable to Icahn Enterprises									0	431	43
Capital expenditures									0	125	171
Depreciation and amortization									0	47	58
Disposal group, including discontinued operation, net gains (losses) on investment activities									$ 0	$ 0	$ 2