Segment Reporting, Balance Sheets (Details) - USD ($) $ in Millions	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting, Asset Reconciling Item [Line Items]
Cash and cash equivalents	$ 3,794	$ 2,656
Cash held at consolidated affiliated partnerships and restricted cash	1,151	2,682
Investments	9,945	8,337
Accounts receivable, net	475	474
Inventories, net	1,812	1,779
Property, plant and equipment, net	4,541	4,688
Goodwill and intangible assets, net	713	748
Other assets	2,208	2,125
Total Assets	24,639	23,489
Accounts payable, accrued expenses and other liabilities	4,315	2,715
Securities sold, not yet purchased, at fair value	1,190	468
Debt	8,192	7,326
Total liabilities	13,697	10,509
Equity attributable to Icahn Enterprises	5,456	6,560
Equity attributable to non-controlling interests	5,486	6,420
Total equity	10,942	12,980	$ 11,486	$ 8,094
Total Liabilities and Equity	24,639	23,489
Investment Segment
Segment Reporting, Asset Reconciling Item [Line Items]
Cash and cash equivalents	11	5
Cash held at consolidated affiliated partnerships and restricted cash	989	2,648
Investments	9,207	6,867
Accounts receivable, net	0	0
Inventories, net	0	0
Property, plant and equipment, net	0	0
Goodwill and intangible assets, net	0	0
Other assets	1,076	1,230
Total Assets	11,283	10,750
Accounts payable, accrued expenses and other liabilities	1,310	181
Securities sold, not yet purchased, at fair value	1,190	468
Debt	0	0
Total liabilities	2,500	649
Equity attributable to Icahn Enterprises	4,296	5,066
Equity attributable to non-controlling interests	4,487	5,035
Total equity	8,783	10,101
Total Liabilities and Equity	11,283	10,750
Energy Segment
Segment Reporting, Asset Reconciling Item [Line Items]
Cash and cash equivalents	652	668
Cash held at consolidated affiliated partnerships and restricted cash	0	0
Investments	81	84
Accounts receivable, net	182	169
Inventories, net	390	380
Property, plant and equipment, net	2,888	3,027
Goodwill and intangible assets, net	258	278
Other assets	222	225
Total Assets	4,673	4,831
Accounts payable, accrued expenses and other liabilities	1,180	1,043
Securities sold, not yet purchased, at fair value	0	0
Debt	1,195	1,170
Total liabilities	2,375	2,213
Equity attributable to Icahn Enterprises	1,312	1,274
Equity attributable to non-controlling interests	986	1,344
Total equity	2,298	2,618
Total Liabilities and Equity	4,673	4,831
Automotive Segment
Segment Reporting, Asset Reconciling Item [Line Items]
Cash and cash equivalents	46	43
Cash held at consolidated affiliated partnerships and restricted cash	0	0
Investments	120	59
Accounts receivable, net	143	149
Inventories, net	1,215	1,203
Property, plant and equipment, net	916	941
Goodwill and intangible assets, net	382	412
Other assets	673	217
Total Assets	3,495	3,024
Accounts payable, accrued expenses and other liabilities	1,340	905
Securities sold, not yet purchased, at fair value	0	0
Debt	405	372
Total liabilities	1,745	1,277
Equity attributable to Icahn Enterprises	1,750	1,747
Equity attributable to non-controlling interests	0	0
Total equity	1,750	1,747
Total Liabilities and Equity	3,495	3,024
Food Packaging Segment
Segment Reporting, Asset Reconciling Item [Line Items]
Cash and cash equivalents	22	46
Cash held at consolidated affiliated partnerships and restricted cash	1	1
Investments	0	0
Accounts receivable, net	78	74
Inventories, net	100	93
Property, plant and equipment, net	161	169
Goodwill and intangible assets, net	30	32
Other assets	125	96
Total Assets	517	511
Accounts payable, accrued expenses and other liabilities	196	164
Securities sold, not yet purchased, at fair value	0	0
Debt	268	273
Total liabilities	464	437
Equity attributable to Icahn Enterprises	40	55
Equity attributable to non-controlling interests	13	19
Total equity	53	74
Total Liabilities and Equity	517	511
Metals Segment
Segment Reporting, Asset Reconciling Item [Line Items]
Cash and cash equivalents	3	20
Cash held at consolidated affiliated partnerships and restricted cash	6	1
Investments	0	0
Accounts receivable, net	32	48
Inventories, net	32	39
Property, plant and equipment, net	122	115
Goodwill and intangible assets, net	11	2
Other assets	27	8
Total Assets	233	233
Accounts payable, accrued expenses and other liabilities	70	56
Securities sold, not yet purchased, at fair value	0	0
Debt	7	0
Total liabilities	77	56
Equity attributable to Icahn Enterprises	156	177
Equity attributable to non-controlling interests	0	0
Total equity	156	177
Total Liabilities and Equity	233	233
Real Estate Segment
Segment Reporting, Asset Reconciling Item [Line Items]
Cash and cash equivalents	53	39
Cash held at consolidated affiliated partnerships and restricted cash	2	26
Investments	15	15
Accounts receivable, net	4	3
Inventories, net	0	0
Property, plant and equipment, net	386	367
Goodwill and intangible assets, net	8	24
Other assets	46	34
Total Assets	514	508
Accounts payable, accrued expenses and other liabilities	38	41
Securities sold, not yet purchased, at fair value	0	0
Debt	2	2
Total liabilities	40	43
Equity attributable to Icahn Enterprises	474	465
Equity attributable to non-controlling interests	0	0
Total equity	474	465
Total Liabilities and Equity	514	508
Home Fashion Segment
Segment Reporting, Asset Reconciling Item [Line Items]
Cash and cash equivalents	1	1
Cash held at consolidated affiliated partnerships and restricted cash	7	2
Investments	0	0
Accounts receivable, net	36	31
Inventories, net	75	64
Property, plant and equipment, net	68	69
Goodwill and intangible assets, net	24	0
Other assets	20	5
Total Assets	231	172
Accounts payable, accrued expenses and other liabilities	66	35
Securities sold, not yet purchased, at fair value	0	0
Debt	18	4
Total liabilities	84	39
Equity attributable to Icahn Enterprises	147	133
Equity attributable to non-controlling interests	0	0
Total equity	147	133
Total Liabilities and Equity	231	172
Mining Segment
Segment Reporting, Asset Reconciling Item [Line Items]
Cash and cash equivalents	0	0
Cash held at consolidated affiliated partnerships and restricted cash	0	0
Investments	0	0
Accounts receivable, net	0	0
Inventories, net	0	0
Property, plant and equipment, net	0	0
Goodwill and intangible assets, net	0	0
Other assets	0	299
Total Assets	0	299
Accounts payable, accrued expenses and other liabilities	0	112
Securities sold, not yet purchased, at fair value	0	0
Debt	0	0
Total liabilities	0	112
Equity attributable to Icahn Enterprises	0	165
Equity attributable to non-controlling interests	0	22
Total equity	0	187
Total Liabilities and Equity	0	299
Holding Company
Segment Reporting, Asset Reconciling Item [Line Items]
Cash and cash equivalents	3,006	1,834
Cash held at consolidated affiliated partnerships and restricted cash	146	4
Investments	522	1,312
Accounts receivable, net	0	0
Inventories, net	0	0
Property, plant and equipment, net	0	0
Goodwill and intangible assets, net	0	0
Other assets	19	11
Total Assets	3,693	3,161
Accounts payable, accrued expenses and other liabilities	115	178
Securities sold, not yet purchased, at fair value	0	0
Debt	6,297	5,505
Total liabilities	6,412	5,683
Equity attributable to Icahn Enterprises	(2,719)	(2,522)
Equity attributable to non-controlling interests	0	0
Total equity	(2,719)	(2,522)
Total Liabilities and Equity	$ 3,693	$ 3,161