Segment Reporting - Condensed Statements of Operations (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Aug. 31, 2025	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net sales		$ 8,631	$ 9,193	$ 11,077
Other revenues from operations		664	707	770
Net loss from investment activities		(183)	(421)	(1,575)
Interest and dividend income		288	477	636
Gain (loss) on disposition of assets, net		247	(4)	8
Other income (loss), net		11	68	18
Total revenues		9,658	10,020	10,934
Cost of goods sold		7,978	8,619	9,327
Other expenses from operations		599	603	643
Dividend expense		35	56	87
Selling, general and administrative		837	783	852
Impairment		40		7
Restructuring, net		10	3	1
Credit loss on notes receivable				139
Loss on deconsolidation of subsidiary				246
Interest expense		504	523	554
Total Expenses		10,003	10,587	11,856
(Loss) income before income tax (expense) benefit		(345)	(567)	(922)
Income tax (expense) benefit		19	25	(90)
Net (loss) income		(326)	(542)	(1,012)
Less: net loss (income) attributable to non-controlling interests		(27)	(97)	(328)
Net income (loss) attributable to Icahn Enterprises		(299)	(445)	(684)
Capital expenditures		341	280	303
Depreciation and amortization		$ 603	511	518
Number of reportable segments not disclosed		false
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		(183)	(421)	(1,575)
Interest and dividend income		189	335	497
Gain (loss) on disposition of assets, net		0
Other income (loss), net		6
Total revenues		12	(86)	(1,078)
Cost of goods sold		0
Other expenses from operations		0
Dividend expense		35	56	87
Selling, general and administrative		16	22	26
Impairment		0
Restructuring, net		0
Interest expense		15	78	162
Total Expenses		66	156	275
(Loss) income before income tax (expense) benefit		(54)	(242)	(1,353)
Income tax (expense) benefit		0
Net (loss) income		(54)	(242)	(1,353)
Less: net loss (income) attributable to non-controlling interests		(59)	(110)	(652)
Net income (loss) attributable to Icahn Enterprises		5	(132)	(701)
Capital expenditures		0
Depreciation and amortization		0
Energy Segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net sales		7,162	7,610	9,247
Other revenues from operations		0
Net loss from investment activities		0
Interest and dividend income		30	37	38
Gain (loss) on disposition of assets, net		(7)		(2)
Other income (loss), net		3	37	14
Total revenues		7,188	7,684	9,297
Cost of goods sold		6,860	7,450	8,019
Other expenses from operations		0
Dividend expense		0
Selling, general and administrative		178	166	168
Impairment		0
Restructuring, net		0
Interest expense		135	114	90
Total Expenses		7,173	7,730	8,277
(Loss) income before income tax (expense) benefit		15	(46)	1,020
Income tax (expense) benefit		27	42	(189)
Net (loss) income		42	(4)	831
Less: net loss (income) attributable to non-controlling interests		38	14	323
Net income (loss) attributable to Icahn Enterprises		4	(18)	508
Capital expenditures		185	179	205
Depreciation and amortization		468	363	363
Automotive Segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net sales		835	877	1,047
Other revenues from operations		601	628	694
Net loss from investment activities		0
Interest and dividend income		3	4	3
Gain (loss) on disposition of assets, net		(16)	(7)	10
Other income (loss), net		0	38
Total revenues		1,423	1,540	1,754
Cost of goods sold		591	628	714
Other expenses from operations		537	536	581
Dividend expense		0
Selling, general and administrative		446	405	465
Impairment		25		7
Restructuring, net		0
Interest expense		2	2	3
Total Expenses		1,601	1,571	1,770
(Loss) income before income tax (expense) benefit		(178)	(31)	(16)
Income tax (expense) benefit		48	15	10
Net (loss) income		(130)	(16)	(6)
Less: net loss (income) attributable to non-controlling interests		0
Net income (loss) attributable to Icahn Enterprises		(130)	(16)	(6)
Capital expenditures		95	55	79
Depreciation and amortization		65	74	81
Food Packaging Segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net sales		364	404	446
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 income (loss), net		(2)	(11)	(11)
Total revenues		362	393	435
Cost of goods sold		327	336	352
Other expenses from operations		0
Dividend expense		0
Selling, general and administrative		54	50	54
Impairment		15
Restructuring, net		9	2
Interest expense		10	11	12
Total Expenses		415	399	418
(Loss) income before income tax (expense) benefit		(53)	(6)	17
Income tax (expense) benefit		(13)		(4)
Net (loss) income		(66)	(6)	13
Less: net loss (income) attributable to non-controlling interests		(6)	(1)	1
Net income (loss) attributable to Icahn Enterprises		(60)	(5)	12
Capital expenditures		35	15	14
Depreciation and amortization		19	24	25
Real Estate Segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net sales		1	21	69
Other revenues from operations		58	75	73
Net loss from investment activities		0
Interest and dividend income		7	1
Gain (loss) on disposition of assets, net	$ 223	270
Other income (loss), net		0		1
Total revenues		336	97	143
Cost of goods sold		1	15	48
Other expenses from operations		62	67	62
Dividend expense		0
Selling, general and administrative		22	19	17
Impairment		0
Restructuring, net		0
Interest expense		0
Total Expenses		85	101	127
(Loss) income before income tax (expense) benefit		251	(4)	16
Income tax (expense) benefit		5
Net (loss) income		256	(4)	16
Less: net loss (income) attributable to non-controlling interests		0
Net income (loss) attributable to Icahn Enterprises		256	(4)	16
Capital expenditures		18	26	3
Depreciation and amortization		18	15	13
Home Fashion Segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net sales		170	176	175
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 income (loss), net		1	(4)
Total revenues		171	172	175
Cost of goods sold		139	135	138
Other expenses from operations		0
Dividend expense		0
Selling, general and administrative		43	43	41
Impairment		0
Restructuring, net		1	1	1
Interest expense		2	1	1
Total Expenses		185	180	181
(Loss) income before income tax (expense) benefit		(14)	(8)	(6)
Income tax (expense) benefit		0
Net (loss) income		(14)	(8)	(6)
Less: net loss (income) attributable to non-controlling interests		0
Net income (loss) attributable to Icahn Enterprises		(14)	(8)	(6)
Capital expenditures		8	5	2
Depreciation and amortization		5	6	7
Pharma Segment
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net sales		99	105	93
Other revenues from operations		5	4	3
Net loss from investment activities		0
Interest and dividend income		1	2	1
Gain (loss) on disposition of assets, net		0
Other income (loss), net		0		1
Total revenues		105	111	98
Cost of goods sold		60	55	56
Other expenses from operations		0
Dividend expense		0
Selling, general and administrative		49	47	45
Impairment		0
Restructuring, net		0
Interest expense		0
Total Expenses		109	102	101
(Loss) income before income tax (expense) benefit		(4)	9	(3)
Income tax (expense) benefit		0
Net (loss) income		(4)	9	(3)
Less: net loss (income) attributable to non-controlling interests		0
Net income (loss) attributable to Icahn Enterprises		(4)	9	(3)
Capital expenditures		0
Depreciation and amortization		28	28	28
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
Interest and dividend income		58	98	97
Gain (loss) on disposition of assets, net		0	3
Other income (loss), net		3	8	13
Total revenues		61	109	110
Cost of goods sold		0
Other expenses from operations		0
Dividend expense		0
Selling, general and administrative		29	31	36
Impairment		0
Restructuring, net		0
Credit loss on notes receivable				139
Loss on deconsolidation of subsidiary				246
Interest expense		340	317	286
Total Expenses		369	348	707
(Loss) income before income tax (expense) benefit		(308)	(239)	(597)
Income tax (expense) benefit		(48)	(32)	93
Net (loss) income		(356)	(271)	(504)
Less: net loss (income) attributable to non-controlling interests		0
Net income (loss) attributable to Icahn Enterprises		(356)	(271)	(504)
Capital expenditures		0
Depreciation and amortization		$ 0	$ 1	$ 1