Condensed Statement of Operations By Reporting Segment (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenues:
Net sales	$ 2,300	$ 2,364
Other revenues from operations	162	158
Net (loss) gain from investment activities	(674)	432
Interest and dividend income	64	26
Other income, net	3	3
Total Revenues	1,855	2,983
Expenses:
Cost of goods sold	1,900	1,987
Other expenses from operations	131	125
Selling, general and administrative	336	338
Restructuring, net	7	2
Interest expense	139	147
Total Expenses	2,513	2,599
Income (loss) from continuing operations before income tax benefit (expense)	(658)	384
Income tax expense	(6)	(17)
(Loss) income from continuing operations	(664)	367
Less: net income (loss) attributable to non-controlling interests	(270)	269
Net (loss) income attributable to Icahn Enterprises from continuing operations	(394)	98
Supplemental information:
Capital expenditures	65	62
Depreciation and amortization	123	128
Investment Segment
Revenues:
Net sales	0	0
Other revenues from operations	0	0
Net (loss) gain from investment activities	(609)	410
Interest and dividend income	42	18
Other income, net	(1)	0
Total Revenues	(568)	428
Expenses:
Cost of goods sold	0	0
Other expenses from operations	0	0
Selling, general and administrative	2	1
Restructuring, net	0	0
Interest expense	18	26
Total Expenses	20	27
Income (loss) from continuing operations before income tax benefit (expense)	(588)	401
Income tax expense	0	0
(Loss) income from continuing operations	(588)	401
Less: net income (loss) attributable to non-controlling interests	(293)	240
Net (loss) income attributable to Icahn Enterprises from continuing operations	(295)	161
Supplemental information:
Capital expenditures	0	0
Depreciation and amortization	0	0
Energy Segment
Revenues:
Net sales	1,486	1,537
Other revenues from operations	0	0
Net (loss) gain from investment activities	0	0
Interest and dividend income	0	0
Other income, net	1	2
Total Revenues	1,487	1,539
Expenses:
Cost of goods sold	1,303	1,385
Other expenses from operations	0	0
Selling, general and administrative	37	32
Restructuring, net	0	0
Interest expense	26	27
Total Expenses	1,366	1,444
Income (loss) from continuing operations before income tax benefit (expense)	121	95
Income tax expense	(31)	(14)
(Loss) income from continuing operations	90	81
Less: net income (loss) attributable to non-controlling interests	24	31
Net (loss) income attributable to Icahn Enterprises from continuing operations	66	50
Supplemental information:
Capital expenditures	29	20
Depreciation and amortization	83	83
Automotive Segment
Revenues:
Net sales	550	549
Other revenues from operations	143	137
Net (loss) gain from investment activities	0	0
Interest and dividend income	0	0
Other income, net	4	0
Total Revenues	697	686
Expenses:
Cost of goods sold	375	361
Other expenses from operations	119	113
Selling, general and administrative	252	258
Restructuring, net	0	0
Interest expense	5	3
Total Expenses	751	735
Income (loss) from continuing operations before income tax benefit (expense)	(54)	(49)
Income tax expense	12	15
(Loss) income from continuing operations	(42)	(34)
Less: net income (loss) attributable to non-controlling interests	0	0
Net (loss) income attributable to Icahn Enterprises from continuing operations	(42)	(34)
Supplemental information:
Capital expenditures	13	19
Depreciation and amortization	24	24
Food Packaging Segment
Revenues:
Net sales	95	97
Other revenues from operations	0	0
Net (loss) gain from investment activities	0	0
Interest and dividend income	0	0
Other income, net	(3)	(6)
Total Revenues	92	91
Expenses:
Cost of goods sold	75	77
Other expenses from operations	0	0
Selling, general and administrative	15	15
Restructuring, net	7	0
Interest expense	4	4
Total Expenses	101	96
Income (loss) from continuing operations before income tax benefit (expense)	(9)	(5)
Income tax expense	4	2
(Loss) income from continuing operations	(5)	(3)
Less: net income (loss) attributable to non-controlling interests	(2)	0
Net (loss) income attributable to Icahn Enterprises from continuing operations	(3)	(3)
Supplemental information:
Capital expenditures	7	5
Depreciation and amortization	6	7
Metals Segment
Revenues:
Net sales	93	118
Other revenues from operations	0	0
Net (loss) gain from investment activities	0	0
Interest and dividend income	0	0
Other income, net	0	1
Total Revenues	93	119
Expenses:
Cost of goods sold	92	110
Other expenses from operations	0	0
Selling, general and administrative	4	5
Restructuring, net	0	0
Interest expense	0	0
Total Expenses	96	115
Income (loss) from continuing operations before income tax benefit (expense)	(3)	4
Income tax expense	0	0
(Loss) income from continuing operations	(3)	4
Less: net income (loss) attributable to non-controlling interests	0	0
Net (loss) income attributable to Icahn Enterprises from continuing operations	(3)	4
Supplemental information:
Capital expenditures	5	1
Depreciation and amortization	4	5
Real Estate Segment
Revenues:
Net sales	2	1
Other revenues from operations	19	21
Net (loss) gain from investment activities	0	0
Interest and dividend income	0	5
Other income, net	2	0
Total Revenues	23	27
Expenses:
Cost of goods sold	2	1
Other expenses from operations	12	12
Selling, general and administrative	5	6
Restructuring, net	0	0
Interest expense	0	1
Total Expenses	19	20
Income (loss) from continuing operations before income tax benefit (expense)	4	7
Income tax expense	0	0
(Loss) income from continuing operations	4	7
Less: net income (loss) attributable to non-controlling interests	0	0
Net (loss) income attributable to Icahn Enterprises from continuing operations	4	7
Supplemental information:
Capital expenditures	6	3
Depreciation and amortization	4	5
Home Fashion Segment
Revenues:
Net sales	39	42
Other revenues from operations	0	0
Net (loss) gain from investment activities	0	0
Interest and dividend income	0	0
Other income, net	0	0
Total Revenues	39	42
Expenses:
Cost of goods sold	33	36
Other expenses from operations	0	0
Selling, general and administrative	10	9
Restructuring, net	0	2
Interest expense	0	0
Total Expenses	43	47
Income (loss) from continuing operations before income tax benefit (expense)	(4)	(5)
Income tax expense	0	0
(Loss) income from continuing operations	(4)	(5)
Less: net income (loss) attributable to non-controlling interests	0	0
Net (loss) income attributable to Icahn Enterprises from continuing operations	(4)	(5)
Supplemental information:
Capital expenditures	1	1
Depreciation and amortization	2	2
Mining Segment
Revenues:
Net sales	35	20
Other revenues from operations	0	0
Net (loss) gain from investment activities	0	0
Interest and dividend income	1	0
Other income, net	0	0
Total Revenues	36	20
Expenses:
Cost of goods sold	20	17
Other expenses from operations	0	0
Selling, general and administrative	7	6
Restructuring, net	0	0
Interest expense	2	2
Total Expenses	29	25
Income (loss) from continuing operations before income tax benefit (expense)	7	(5)
Income tax expense	(1)	(1)
(Loss) income from continuing operations	6	(6)
Less: net income (loss) attributable to non-controlling interests	1	(2)
Net (loss) income attributable to Icahn Enterprises from continuing operations	5	(4)
Supplemental information:
Capital expenditures	4	13
Depreciation and amortization	0	2
Railcar Segment
Revenues:
Net sales	0	0
Other revenues from operations	0	0
Net (loss) gain from investment activities	0	0
Interest and dividend income	0	0
Other income, net	0	5
Total Revenues	0	5
Expenses:
Cost of goods sold	0	0
Other expenses from operations	0	0
Selling, general and administrative	0	0
Restructuring, net	0	0
Interest expense	0	0
Total Expenses	0	0
Income (loss) from continuing operations before income tax benefit (expense)	0	5
Income tax expense	0	0
(Loss) income from continuing operations	0	5
Less: net income (loss) attributable to non-controlling interests	0	0
Net (loss) income attributable to Icahn Enterprises from continuing operations	0	5
Supplemental information:
Capital expenditures	0	0
Depreciation and amortization	0	0
Holding Company
Revenues:
Net sales	0	0
Other revenues from operations	0	0
Net (loss) gain from investment activities	(65)	22
Interest and dividend income	21	3
Other income, net	0	1
Total Revenues	(44)	26
Expenses:
Cost of goods sold	0	0
Other expenses from operations	0	0
Selling, general and administrative	4	6
Restructuring, net	0	0
Interest expense	84	84
Total Expenses	88	90
Income (loss) from continuing operations before income tax benefit (expense)	(132)	(64)
Income tax expense	10	(19)
(Loss) income from continuing operations	(122)	(83)
Less: net income (loss) attributable to non-controlling interests	0	0
Net (loss) income attributable to Icahn Enterprises from continuing operations	(122)	(83)
Supplemental information:
Capital expenditures	0	0
Depreciation and amortization	$ 0	$ 0