Condensed Balance Sheets By Reporting Segment (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
ASSETS
Cash and cash equivalents	$ 2,764	$ 2,656
Cash held at consolidated affiliated partnerships and restricted cash	2,299	2,682
Investments	8,103	8,337
Accounts receivable, net	517	474
Inventories, net	1,852	1,779
Property, plant and equipment, net	4,682	4,688
Goodwill and intangible assets, net	719	748
Assets held for sale	364	333
Other assets	2,524	1,792
Total assets	23,824	23,489
LIABILITIES AND EQUITY
Accounts payable, accrued expenses and other liabilities	4,197	2,603
Securities sold, not yet purchased, at fair value	447	468
Liabilities held for sale	136	112
Debt	7,392	7,326
Total liabilities	12,172	10,509
Equity attributable to Icahn Enterprises	5,839	6,560
Equity attributable to non-controlling interests	5,813	6,420
Total equity	11,652	12,980	$ 11,862	$ 11,486
Total liabilities and equity	23,824	23,489
Investment Segment
ASSETS
Cash and cash equivalents	7	5
Cash held at consolidated affiliated partnerships and restricted cash	2,286	2,648
Investments	7,130	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
Assets held for sale	0	0
Other assets	1,268	1,230
Total assets	10,691	10,750
LIABILITIES AND EQUITY
Accounts payable, accrued expenses and other liabilities	730	181
Securities sold, not yet purchased, at fair value	447	468
Liabilities held for sale	0	0
Debt	0	0
Total liabilities	1,177	649
Equity attributable to Icahn Enterprises	4,772	5,066
Equity attributable to non-controlling interests	4,742	5,035
Total equity	9,514	10,101
Total liabilities and equity	10,691	10,750
Energy Segment
ASSETS
Cash and cash equivalents	467	668
Cash held at consolidated affiliated partnerships and restricted cash	0	0
Investments	83	84
Accounts receivable, net	193	169
Inventories, net	403	380
Property, plant and equipment, net	3,004	3,027
Goodwill and intangible assets, net	273	278
Assets held for sale	33	33
Other assets	232	192
Total assets	4,688	4,831
LIABILITIES AND EQUITY
Accounts payable, accrued expenses and other liabilities	1,171	1,043
Securities sold, not yet purchased, at fair value	0	0
Liabilities held for sale	0	0
Debt	1,196	1,170
Total liabilities	2,367	2,213
Equity attributable to Icahn Enterprises	1,290	1,274
Equity attributable to non-controlling interests	1,031	1,344
Total equity	2,321	2,618
Total liabilities and equity	4,688	4,831
Automotive Segment
ASSETS
Cash and cash equivalents	65	43
Cash held at consolidated affiliated partnerships and restricted cash	0	0
Investments	86	59
Accounts receivable, net	168	149
Inventories, net	1,233	1,203
Property, plant and equipment, net	951	941
Goodwill and intangible assets, net	391	412
Assets held for sale	0	0
Other assets	769	217
Total assets	3,663	3,024
LIABILITIES AND EQUITY
Accounts payable, accrued expenses and other liabilities	1,426	905
Securities sold, not yet purchased, at fair value	0	0
Liabilities held for sale	0	0
Debt	405	372
Total liabilities	1,831	1,277
Equity attributable to Icahn Enterprises	1,832	1,747
Equity attributable to non-controlling interests	0	0
Total equity	1,832	1,747
Total liabilities and equity	3,663	3,024
Food Packaging Segment
ASSETS
Cash and cash equivalents	33	46
Cash held at consolidated affiliated partnerships and restricted cash	1	1
Investments	0	0
Accounts receivable, net	76	74
Inventories, net	103	93
Property, plant and equipment, net	168	169
Goodwill and intangible assets, net	32	32
Assets held for sale	0	0
Other assets	139	96
Total assets	552	511
LIABILITIES AND EQUITY
Accounts payable, accrued expenses and other liabilities	212	164
Securities sold, not yet purchased, at fair value	0	0
Liabilities held for sale	0	0
Debt	271	273
Total liabilities	483	437
Equity attributable to Icahn Enterprises	52	55
Equity attributable to non-controlling interests	17	19
Total equity	69	74
Total liabilities and equity	552	511
Metals Segment
ASSETS
Cash and cash equivalents	11	20
Cash held at consolidated affiliated partnerships and restricted cash	1	1
Investments	0	0
Accounts receivable, net	49	48
Inventories, net	40	39
Property, plant and equipment, net	115	115
Goodwill and intangible assets, net	2	2
Assets held for sale	1	1
Other assets	22	7
Total assets	241	233
LIABILITIES AND EQUITY
Accounts payable, accrued expenses and other liabilities	66	56
Securities sold, not yet purchased, at fair value	0	0
Liabilities held for sale	0	0
Debt	1	0
Total liabilities	67	56
Equity attributable to Icahn Enterprises	174	177
Equity attributable to non-controlling interests	0	0
Total equity	174	177
Total liabilities and equity	241	233
Real Estate Segment
ASSETS
Cash and cash equivalents	41	39
Cash held at consolidated affiliated partnerships and restricted cash	2	26
Investments	15	15
Accounts receivable, net	3	3
Inventories, net	0	0
Property, plant and equipment, net	376	367
Goodwill and intangible assets, net	21	24
Assets held for sale	0	0
Other assets	34	34
Total assets	492	508
LIABILITIES AND EQUITY
Accounts payable, accrued expenses and other liabilities	46	41
Securities sold, not yet purchased, at fair value	0	0
Liabilities held for sale	0	0
Debt	2	2
Total liabilities	48	43
Equity attributable to Icahn Enterprises	444	465
Equity attributable to non-controlling interests	0	0
Total equity	444	465
Total liabilities and equity	492	508
Home Fashion Segment
ASSETS
Cash and cash equivalents	1	1
Cash held at consolidated affiliated partnerships and restricted cash	2	2
Investments	0	0
Accounts receivable, net	28	31
Inventories, net	73	64
Property, plant and equipment, net	68	69
Goodwill and intangible assets, net	0	0
Assets held for sale	0	0
Other assets	11	5
Total assets	183	172
LIABILITIES AND EQUITY
Accounts payable, accrued expenses and other liabilities	42	35
Securities sold, not yet purchased, at fair value	0	0
Liabilities held for sale	0	0
Debt	12	4
Total liabilities	54	39
Equity attributable to Icahn Enterprises	129	133
Equity attributable to non-controlling interests	0	0
Total equity	129	133
Total liabilities and equity	183	172
Mining 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	330	299
Other assets	0	0
Total assets	330	299
LIABILITIES AND EQUITY
Accounts payable, accrued expenses and other liabilities	0	0
Securities sold, not yet purchased, at fair value	0	0
Liabilities held for sale	136	112
Debt	0	0
Total liabilities	136	112
Equity attributable to Icahn Enterprises	171	165
Equity attributable to non-controlling interests	23	22
Total equity	194	187
Total liabilities and equity	330	299
Holding Company
ASSETS
Cash and cash equivalents	2,139	1,834
Cash held at consolidated affiliated partnerships and restricted cash	7	4
Investments	789	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
Assets held for sale	0	0
Other assets	49	11
Total assets	2,984	3,161
LIABILITIES AND EQUITY
Accounts payable, accrued expenses and other liabilities	504	178
Securities sold, not yet purchased, at fair value	0	0
Liabilities held for sale	0	0
Debt	5,505	5,505
Total liabilities	6,009	5,683
Equity attributable to Icahn Enterprises	(3,025)	(2,522)
Equity attributable to non-controlling interests	0	0
Total equity	(3,025)	(2,522)
Total liabilities and equity	$ 2,984	$ 3,161