Segment and Geographic Reporting - Condensed Statements of Operations (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net sales		$ 11,077	$ 13,378	$ 10,304
Other revenues from operations		770	748	647
Net loss from investment activities		(1,575)	(168)	193
Interest and dividend income		636	328	137
Gain (loss) on disposition of assets, net		8	(8)	141
Other (loss) income, net		(69)	(177)	(84)
Total revenues		10,847	14,101	11,338
Cost of goods sold		9,327	11,689	9,485
Other expenses from operations		643	583	522
Selling, general and administrative		852	1,250	1,238
Restructuring, net		1	2	5
Impairment		7
Credit loss on related party note receivable		139
Loss on deconsolidation of subsidiary		246
Interest expense		554	568	666
Total Expenses		11,769	14,092	11,916
(Loss) income before income tax (expense) benefit		(922)	9	(578)
Income tax (expense) benefit		(90)	(34)	78
Net (loss) income		(1,012)	(25)	(500)
Less: net (loss) income from continuing operations attributable to non-controlling interests		(328)	158	18
Net (loss) income from continuing operations attributable to Icahn Enterprises		(684)	(183)	(518)
Capital expenditures		303	338	305
Depreciation and amortization		518	509	517
Investment Segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net sales		0
Other revenues from operations		0
Net loss from investment activities		(1,575)	(216)	145
Interest and dividend income		497	288	132
Gain (loss) on disposition of assets, net		0
Other (loss) income, net		(87)	(95)	(75)
Total revenues		(1,165)	(23)	202
Cost of goods sold		0
Other expenses from operations		0
Selling, general and administrative		26	27	16
Restructuring, net		0
Impairment		0
Credit loss on related party note receivable		0
Loss on deconsolidation of subsidiary		0
Interest expense		162	173	218
Total Expenses		188	200	234
(Loss) income before income tax (expense) benefit		(1,353)	(223)	(32)
Income tax (expense) benefit		0
Net (loss) income		(1,353)	(223)	(32)
Less: net (loss) income from continuing operations attributable to non-controlling interests		(652)	(134)	(16)
Net (loss) income from continuing operations attributable to Icahn Enterprises		(701)	(89)	(16)
Capital expenditures		0
Depreciation and amortization		0
Energy
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net sales		9,247	10,896	7,242
Other revenues from operations		0
Net loss from investment activities		0		81
Interest and dividend income		38	8
Gain (loss) on disposition of assets, net		(2)	(11)	(3)
Other (loss) income, net		14	(78)	7
Total revenues		9,297	10,815	7,327
Cost of goods sold		8,019	9,811	7,069
Other expenses from operations		0
Selling, general and administrative		168	176	147
Restructuring, net		0
Impairment		0
Credit loss on related party note receivable		0
Loss on deconsolidation of subsidiary		0
Interest expense		90	92	109
Total Expenses		8,277	10,079	7,325
(Loss) income before income tax (expense) benefit		1,020	736	2
Income tax (expense) benefit		(189)	(140)	27
Net (loss) income		831	596	29
Less: net (loss) income from continuing operations attributable to non-controlling interests		323	292	34
Net (loss) income from continuing operations attributable to Icahn Enterprises		508	304	(5)
Capital expenditures		205	191	224
Depreciation and amortization		363	353	343
Automotive Segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net sales		1,047	1,707	1,789
Other revenues from operations		694	687	605
Net loss from investment activities		0
Interest and dividend income		3
Gain (loss) on disposition of assets, net		10	3	(22)
Other (loss) income, net		0	1	(2)
Total revenues		1,754	2,398	2,370
Cost of goods sold		714	1,247	1,339
Other expenses from operations		581	528	475
Selling, general and administrative		465	867	877
Restructuring, net		0		4
Impairment	$ 7	7
Credit loss on related party note receivable		0
Loss on deconsolidation of subsidiary		0
Interest expense		3	2	7
Total Expenses		1,770	2,644	2,702
(Loss) income before income tax (expense) benefit		(16)	(246)	(332)
Income tax (expense) benefit		10	54	72
Net (loss) income		(6)	(192)	(260)
Less: net (loss) income from continuing operations attributable to non-controlling interests		0
Net (loss) income from continuing operations attributable to Icahn Enterprises		(6)	(192)	(260)
Capital expenditures		79	114	48
Depreciation and amortization		81	80	87
Food Packaging Segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net sales		446	431	416
Other revenues from operations		0
Net loss from investment activities		0
Interest and dividend income		0
Gain (loss) on disposition of assets, net		0
Other (loss) income, net		(11)	(5)	(14)
Total revenues		435	426	402
Cost of goods sold		352	357	343
Other expenses from operations		0
Selling, general and administrative		54	52	50
Restructuring, net		0		1
Impairment		0
Credit loss on related party note receivable		0
Loss on deconsolidation of subsidiary		0
Interest expense		12	8	6
Total Expenses		418	417	400
(Loss) income before income tax (expense) benefit		17	9	2
Income tax (expense) benefit		(4)	(7)	(4)
Net (loss) income		13	2	(2)
Less: net (loss) income from continuing operations attributable to non-controlling interests		1
Net (loss) income from continuing operations attributable to Icahn Enterprises		12	2	(2)
Capital expenditures		14	22	17
Depreciation and amortization		25	27	28
Real Estate Segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net sales		69	61	55
Other revenues from operations		73	57	38
Gain (loss) on disposition of assets, net				3
Other (loss) income, net		1
Total revenues		143	118	96
Cost of goods sold		48	40	44
Other expenses from operations		62	55	47
Selling, general and administrative		17	16	13
Total Expenses		127	111	104
(Loss) income before income tax (expense) benefit		16	7	(8)
Net (loss) income		16	7	(8)
Net (loss) income from continuing operations attributable to Icahn Enterprises		16	7	(8)
Capital expenditures		3	9	10
Depreciation and amortization		13	13	9
Home Fashion Segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net sales		175	217	197
Other revenues from operations		0
Net loss from investment activities		0
Interest and dividend income		0
Gain (loss) on disposition of assets, net		0
Other (loss) income, net		0
Total revenues		175	217	197
Cost of goods sold		138	186	159
Other expenses from operations		0
Selling, general and administrative		41	48	46
Restructuring, net		1	2
Impairment		0
Credit loss on related party note receivable		0
Loss on deconsolidation of subsidiary		0
Interest expense		1	3	2
Total Expenses		181	239	207
(Loss) income before income tax (expense) benefit		(6)	(22)	(10)
Income tax (expense) benefit		0		2
Net (loss) income		(6)	(22)	(8)
Less: net (loss) income from continuing operations attributable to non-controlling interests		0
Net (loss) income from continuing operations attributable to Icahn Enterprises		(6)	(22)	(8)
Capital expenditures		2	2	3
Depreciation and amortization		7	7	7
Pharma
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net sales		93	66	81
Other revenues from operations		3	4	4
Net loss from investment activities		0
Interest and dividend income		1	1
Gain (loss) on disposition of assets, net		0
Other (loss) income, net		1	1
Total revenues		98	72	85
Cost of goods sold		56	48	50
Other expenses from operations		0
Selling, general and administrative		45	42	38
Restructuring, net		0
Impairment		0
Credit loss on related party note receivable		0
Loss on deconsolidation of subsidiary		0
Interest expense		0
Total Expenses		101	90	88
(Loss) income before income tax (expense) benefit		(3)	(18)	(3)
Income tax (expense) benefit		0
Net (loss) income		(3)	(18)	(3)
Less: net (loss) income from continuing operations attributable to non-controlling interests		0
Net (loss) income from continuing operations attributable to Icahn Enterprises		(3)	(18)	(3)
Capital expenditures		0
Depreciation and amortization		28	28	28
Metals Segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net sales				524
Gain (loss) on disposition of assets, net				163
Other (loss) income, net				(3)
Total revenues				684
Cost of goods sold				481
Selling, general and administrative				16
Interest expense				1
Total Expenses				498
(Loss) income before income tax (expense) benefit				186
Net (loss) income				186
Net (loss) income from continuing operations attributable to Icahn Enterprises				186
Capital expenditures				3
Depreciation and amortization				14
Holding Company
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net sales		0
Other revenues from operations		0
Net loss from investment activities		0	48	(33)
Interest and dividend income		97	31	5
Gain (loss) on disposition of assets, net		0
Other (loss) income, net		13	(1)	3
Total revenues		110	78	(25)
Cost of goods sold		0
Other expenses from operations		0
Selling, general and administrative		36	22	35
Restructuring, net		0
Impairment		0
Credit loss on related party note receivable		139
Loss on deconsolidation of subsidiary		246
Interest expense		286	290	323
Total Expenses		707	312	358
(Loss) income before income tax (expense) benefit		(597)	(234)	(383)
Income tax (expense) benefit		93	59	(19)
Net (loss) income		(504)	(175)	(402)
Less: net (loss) income from continuing operations attributable to non-controlling interests		0
Net (loss) income from continuing operations attributable to Icahn Enterprises		(504)	(175)	(402)
Capital expenditures		0
Depreciation and amortization		$ 1	$ 1	$ 1