Segment Reporting, Balance Sheets (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
ASSETS
Cash and cash equivalents	$ 2,656	$ 1,164
Cash held at consolidated affiliated partnerships and restricted cash	2,682	747
Investments	8,337	10,015
Accounts receivable, net	474	473
Inventories, net	1,779	1,730
Property, plant and equipment, net	4,703	5,186
Goodwill and intangible assets, net	748	871
Assets held for sale	333	10,263
Other assets	1,684	1,352
Total Assets	23,396	31,801
LIABILITIES AND EQUITY
Accounts payable, accrued expenses and other liabilities	2,444	3,971
Securities sold, not yet purchased, at fair value	468	1,023
Due to brokers	141	1,057
Liabilities held for sale	112	7,010
Debt	7,326	7,372
Total liabilities	10,491	20,433
Equity attributable to Icahn Enterprises	6,529	5,106
Equity attributable to non-controlling interests	6,376	6,262
Total equity	12,905	11,368	$ 8,017	$ 10,033
Total Liabilities and Equity	23,396	31,801
Investment Segment
ASSETS
Cash and cash equivalents	5	17
Cash held at consolidated affiliated partnerships and restricted cash	2,648	734
Investments	6,867	9,532
Accounts receivable, net	0	0
Inventories, net	0	0
Property, plant and equipment, net	0	0
Goodwill and intangible assets, net	0	0
Assets held for sale	0	0
Other assets	1,230	516
Total Assets	10,750	10,799
LIABILITIES AND EQUITY
Accounts payable, accrued expenses and other liabilities	40	1,302
Securities sold, not yet purchased, at fair value	468	1,023
Due to brokers	141	1,057
Liabilities held for sale	0	0
Debt	0	0
Total liabilities	649	3,382
Equity attributable to Icahn Enterprises	5,066	3,052
Equity attributable to non-controlling interests	5,035	4,365
Total equity	10,101	7,417
Total Liabilities and Equity	10,750	10,799
Energy Segment
ASSETS
Cash and cash equivalents	668	482
Cash held at consolidated affiliated partnerships and restricted cash	0	0
Investments	84	83
Accounts receivable, net	169	179
Inventories, net	380	364
Property, plant and equipment, net	3,042	3,234
Goodwill and intangible assets, net	278	298
Assets held for sale	33	0
Other assets	84	60
Total Assets	4,738	4,700
LIABILITIES AND EQUITY
Accounts payable, accrued expenses and other liabilities	1,025	1,125
Securities sold, not yet purchased, at fair value	0	0
Due to brokers	0	0
Liabilities held for sale	0	0
Debt	1,170	1,166
Total liabilities	2,195	2,291
Equity attributable to Icahn Enterprises	1,243	1,098
Equity attributable to non-controlling interests	1,300	1,311
Total equity	2,543	2,409
Total Liabilities and Equity	4,738	4,700
Automotive Segment
ASSETS
Cash and cash equivalents	43	52
Cash held at consolidated affiliated partnerships and restricted cash	0	0
Investments	59	0
Accounts receivable, net	149	128
Inventories, net	1,203	1,145
Property, plant and equipment, net	941	958
Goodwill and intangible assets, net	412	505
Assets held for sale	0	0
Other assets	217	223
Total Assets	3,024	3,011
LIABILITIES AND EQUITY
Accounts payable, accrued expenses and other liabilities	905	944
Securities sold, not yet purchased, at fair value	0	0
Due to brokers	0	0
Liabilities held for sale	0	0
Debt	372	340
Total liabilities	1,277	1,284
Equity attributable to Icahn Enterprises	1,747	1,727
Equity attributable to non-controlling interests	0	0
Total equity	1,747	1,727
Total Liabilities and Equity	3,024	3,011
Food Packaging Segment
ASSETS
Cash and cash equivalents	46	16
Cash held at consolidated affiliated partnerships and restricted cash	1	2
Investments	0	0
Accounts receivable, net	74	78
Inventories, net	93	92
Property, plant and equipment, net	169	170
Goodwill and intangible assets, net	32	36
Assets held for sale	0	0
Other assets	96	93
Total Assets	511	487
LIABILITIES AND EQUITY
Accounts payable, accrued expenses and other liabilities	164	172
Securities sold, not yet purchased, at fair value	0	0
Due to brokers	0	0
Liabilities held for sale	0	0
Debt	273	273
Total liabilities	437	445
Equity attributable to Icahn Enterprises	55	28
Equity attributable to non-controlling interests	19	14
Total equity	74	42
Total Liabilities and Equity	511	487
Metals Segment
ASSETS
Cash and cash equivalents	20	24
Cash held at consolidated affiliated partnerships and restricted cash	1	5
Investments	0	0
Accounts receivable, net	48	40
Inventories, net	39	33
Property, plant and equipment, net	115	110
Goodwill and intangible assets, net	2	3
Assets held for sale	1	2
Other assets	7	9
Total Assets	233	226
LIABILITIES AND EQUITY
Accounts payable, accrued expenses and other liabilities	56	43
Securities sold, not yet purchased, at fair value	0	0
Due to brokers	0	0
Liabilities held for sale	0	0
Debt	0	1
Total liabilities	56	44
Equity attributable to Icahn Enterprises	177	182
Equity attributable to non-controlling interests	0	0
Total equity	177	182
Total Liabilities and Equity	233	226
Real Estate Segment
ASSETS
Cash and cash equivalents	39	32
Cash held at consolidated affiliated partnerships and restricted cash	26	2
Investments	15	16
Accounts receivable, net	3	3
Inventories, net	0	0
Property, plant and equipment, net	367	454
Goodwill and intangible assets, net	24	29
Assets held for sale	0	0
Other assets	34	395
Total Assets	508	931
LIABILITIES AND EQUITY
Accounts payable, accrued expenses and other liabilities	41	63
Securities sold, not yet purchased, at fair value	0	0
Due to brokers	0	0
Liabilities held for sale	0	0
Debt	2	22
Total liabilities	43	85
Equity attributable to Icahn Enterprises	465	846
Equity attributable to non-controlling interests	0	0
Total equity	465	846
Total Liabilities and Equity	508	931
Home Fashion Segment
ASSETS
Cash and cash equivalents	1	0
Cash held at consolidated affiliated partnerships and restricted cash	2	4
Investments	0	0
Accounts receivable, net	31	35
Inventories, net	64	66
Property, plant and equipment, net	69	72
Goodwill and intangible assets, net	0	0
Assets held for sale	0	0
Other assets	5	6
Total Assets	172	183
LIABILITIES AND EQUITY
Accounts payable, accrued expenses and other liabilities	35	34
Securities sold, not yet purchased, at fair value	0	0
Due to brokers	0	0
Liabilities held for sale	0	0
Debt	4	5
Total liabilities	39	39
Equity attributable to Icahn Enterprises	133	144
Equity attributable to non-controlling interests	0	0
Total equity	133	144
Total Liabilities and Equity	172	183
Mining Segment
ASSETS
Cash and cash equivalents	0	15
Cash held at consolidated affiliated partnerships and restricted cash	0	0
Investments	0	0
Accounts receivable, net	0	10
Inventories, net	0	30
Property, plant and equipment, net	0	188
Goodwill and intangible assets, net	0	0
Assets held for sale	299	0
Other assets	0	22
Total Assets	299	265
LIABILITIES AND EQUITY
Accounts payable, accrued expenses and other liabilities	0	45
Securities sold, not yet purchased, at fair value	0	0
Due to brokers	0	0
Liabilities held for sale	112	0
Debt	0	58
Total liabilities	112	103
Equity attributable to Icahn Enterprises	165	138
Equity attributable to non-controlling interests	22	24
Total equity	187	162
Total Liabilities and Equity	299	265
Railcar Segment
ASSETS
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
Assets held for sale	0	14
Other assets	0	0
Total Assets	0	14
LIABILITIES AND EQUITY
Accounts payable, accrued expenses and other liabilities	0	0
Securities sold, not yet purchased, at fair value	0	0
Due to brokers	0	0
Liabilities held for sale	0	0
Debt	0	0
Total liabilities	0	0
Equity attributable to Icahn Enterprises	0	14
Equity attributable to non-controlling interests	0	0
Total equity	0	14
Total Liabilities and Equity	0	14
Holding Company
ASSETS
Cash and cash equivalents	1,834	526
Cash held at consolidated affiliated partnerships and restricted cash	4	0
Investments	1,312	384
Accounts receivable, net	0	0
Inventories, net	0	0
Property, plant and equipment, net	0	0
Goodwill and intangible assets, net	0	0
Assets held for sale	0	0
Other assets	11	28
Total Assets	3,161	938
LIABILITIES AND EQUITY
Accounts payable, accrued expenses and other liabilities	178	243
Securities sold, not yet purchased, at fair value	0	0
Due to brokers	0	0
Liabilities held for sale	0	0
Debt	5,505	5,507
Total liabilities	5,683	5,750
Equity attributable to Icahn Enterprises	(2,522)	(4,821)
Equity attributable to non-controlling interests	0	9
Total equity	(2,522)	(4,812)
Total Liabilities and Equity	$ 3,161	938
Discontinued Operations
ASSETS
Cash and cash equivalents		0
Cash held at consolidated affiliated partnerships and restricted cash		0
Investments		0
Accounts receivable, net		0
Inventories, net		0
Property, plant and equipment, net		0
Goodwill and intangible assets, net		0
Assets held for sale		10,247
Other assets		0
Total Assets		10,247
LIABILITIES AND EQUITY
Accounts payable, accrued expenses and other liabilities		0
Securities sold, not yet purchased, at fair value		0
Due to brokers		0
Liabilities held for sale		7,010
Debt		0
Total liabilities		7,010
Equity attributable to Icahn Enterprises		2,698
Equity attributable to non-controlling interests		539
Total equity		3,237
Total Liabilities and Equity		$ 10,247