Segment Reporting, Balance Sheets (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting, Asset Reconciling Item [Line Items]
Cash and cash equivalents	$ 1,699	$ 3,794
Cash held at consolidated affiliated partnerships and restricted cash	1,592	1,151
Investments	8,913	9,945
Accounts receivable, net	502	483
Inventories, net	1,580	1,795
Property, plant and equipment, net	4,228	4,454
Goodwill and intangible assets, net	958	713
Other assets	5,515	2,304
Total Assets	24,987	24,639
Accounts payable, accrued expenses and other liabilities	5,150	4,315
Securities sold, not yet purchased, at fair value	2,521	1,190
Debt	8,059	8,192
Total liabilities	15,730	13,697
Equity attributable to Icahn Enterprises	3,382	5,456
Equity attributable to non-controlling interests	5,875	5,486
Total equity	9,257	10,942	$ 12,980	$ 11,486
Total Liabilities and Equity	24,987	24,639
Investment Segment
Segment Reporting, Asset Reconciling Item [Line Items]
Cash and cash equivalents	14	11
Cash held at consolidated affiliated partnerships and restricted cash	1,558	989
Investments	8,239	9,207
Other assets	4,308	1,076
Total Assets	14,119	11,283
Accounts payable, accrued expenses and other liabilities	2,256	1,310
Securities sold, not yet purchased, at fair value	2,521	1,190
Total liabilities	4,777	2,500
Equity attributable to Icahn Enterprises	4,283	4,296
Equity attributable to non-controlling interests	5,059	4,487
Total equity	9,342	8,783
Total Liabilities and Equity	14,119	11,283
Energy Segment
Segment Reporting, Asset Reconciling Item [Line Items]
Cash and cash equivalents	667	652
Cash held at consolidated affiliated partnerships and restricted cash	7
Investments	253	81
Accounts receivable, net	178	182
Inventories, net	298	373
Property, plant and equipment, net	2,747	2,888
Goodwill and intangible assets, net	238	258
Other assets	335	239
Total Assets	4,723	4,673
Accounts payable, accrued expenses and other liabilities	1,189	1,180
Debt	1,691	1,195
Total liabilities	2,880	2,375
Equity attributable to Icahn Enterprises	1,039	1,312
Equity attributable to non-controlling interests	804	986
Total equity	1,843	2,298
Total Liabilities and Equity	4,723	4,673
Automotive Segment
Segment Reporting, Asset Reconciling Item [Line Items]
Cash and cash equivalents	45	46
Investments	40	120
Accounts receivable, net	109	143
Inventories, net	1,080	1,215
Property, plant and equipment, net	857	916
Goodwill and intangible assets, net	376	382
Other assets	582	673
Total Assets	3,089	3,495
Accounts payable, accrued expenses and other liabilities	1,167	1,340
Debt	368	405
Total liabilities	1,535	1,745
Equity attributable to Icahn Enterprises	1,554	1,750
Total equity	1,554	1,750
Total Liabilities and Equity	3,089	3,495
Food Packaging Segment
Segment Reporting, Asset Reconciling Item [Line Items]
Cash and cash equivalents	16	22
Cash held at consolidated affiliated partnerships and restricted cash		1
Accounts receivable, net	88	78
Inventories, net	89	100
Property, plant and equipment, net	160	161
Goodwill and intangible assets, net	31	30
Other assets	101	125
Total Assets	485	517
Accounts payable, accrued expenses and other liabilities	181	196
Debt	151	268
Total liabilities	332	464
Equity attributable to Icahn Enterprises	141	40
Equity attributable to non-controlling interests	12	13
Total equity	153	53
Total Liabilities and Equity	485	517
Metals Segment
Segment Reporting, Asset Reconciling Item [Line Items]
Cash and cash equivalents	1	3
Cash held at consolidated affiliated partnerships and restricted cash	2	6
Accounts receivable, net	64	32
Inventories, net	22	32
Property, plant and equipment, net	82	122
Goodwill and intangible assets, net	9	11
Other assets	37	27
Total Assets	217	233
Accounts payable, accrued expenses and other liabilities	73	70
Debt	16	7
Total liabilities	89	77
Equity attributable to Icahn Enterprises	128	156
Total equity	128	156
Total Liabilities and Equity	217	233
Real Estate Segment
Segment Reporting, Asset Reconciling Item [Line Items]
Cash and cash equivalents	21	53
Cash held at consolidated affiliated partnerships and restricted cash	8	2
Investments	15	15
Accounts receivable, net	10	12
Property, plant and equipment, net	310	299
Goodwill and intangible assets, net	1	8
Other assets	121	125
Total Assets	486	514
Accounts payable, accrued expenses and other liabilities	45	38
Debt	1	2
Total liabilities	46	40
Equity attributable to Icahn Enterprises	440	474
Total equity	440	474
Total Liabilities and Equity	486	514
Home Fashion Segment
Segment Reporting, Asset Reconciling Item [Line Items]
Cash and cash equivalents	2	1
Cash held at consolidated affiliated partnerships and restricted cash	6	7
Accounts receivable, net	33	36
Inventories, net	81	75
Property, plant and equipment, net	65	68
Goodwill and intangible assets, net	21	24
Other assets	19	20
Total Assets	227	231
Accounts payable, accrued expenses and other liabilities	65	66
Debt	21	18
Total liabilities	86	84
Equity attributable to Icahn Enterprises	141	147
Total equity	141	147
Total Liabilities and Equity	227	231
Pharma Segment
Segment Reporting, Asset Reconciling Item [Line Items]
Cash and cash equivalents	8
Accounts receivable, net	20
Inventories, net	10
Goodwill and intangible assets, net	282
Other assets	6
Total Assets	326
Accounts payable, accrued expenses and other liabilities	64
Total liabilities	64
Equity attributable to Icahn Enterprises	262
Total equity	262
Total Liabilities and Equity	326
Holding Company
Segment Reporting, Asset Reconciling Item [Line Items]
Cash and cash equivalents	925	3,006
Cash held at consolidated affiliated partnerships and restricted cash	11	146
Investments	366	522
Property, plant and equipment, net	7
Other assets	6	19
Total Assets	1,315	3,693
Accounts payable, accrued expenses and other liabilities	110	115
Debt	5,811	6,297
Total liabilities	5,921	6,412
Equity attributable to Icahn Enterprises	(4,606)	(2,719)
Total equity	(4,606)	(2,719)
Total Liabilities and Equity	$ 1,315	$ 3,693