Basis of Presentation and Summary of Significant Accounting Policies (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Accounting Policies [Line Items]
Total assets	$ 20,858	$ 20,858	$ 27,914
Debt	7,207	7,207	7,096
Fair value of long-term debt	6,900	6,900	6,600
Cash and cash equivalents	2,951	2,951	2,337
Restricted cash	2,995	2,995	2,549
Portion of inventory under LIFO method	228	228	246
Post-retirement benefit liability	34	34	36
Accumulated other comprehensive loss	(55)	$ (55)	(70)
Aggregate general partner ownership interest of parent and operating subsidiary		1.99%
Impairment		$ 7
Icahn Enterprises G.P.
Accounting Policies [Line Items]
Affiliate ownership interest		98.01%
Aggregate general partner ownership interest of parent and operating subsidiary		1.99%
Icahn Enterprises Holdings
Accounting Policies [Line Items]
Percentage of equity ownership in operating subsidiary		99.00%
Affiliate ownership interest		99.00%
Cash held at consolidated affiliated partnerships
Accounting Policies [Line Items]
Restricted cash	1,068	$ 1,068	1,019
Restricted cash
Accounting Policies [Line Items]
Restricted cash	1,927	1,927	1,530
Primary beneficiary
Accounting Policies [Line Items]
Total assets	103	103
Energy
Accounting Policies [Line Items]
Total assets	5,259	5,259	4,735
Debt	2,185	2,185	1,591
Cash and cash equivalents	1,179	1,179	510
Restricted cash	7	7	7
Remaining performance obligation for contracts with an original expected duration of more than one year	10	10
Deferred revenue	$ 49	49	48
Recorded revenue		$ 47	$ 86	$ 30
Lease term	5 years 4 months 24 days	5 years 4 months 24 days	4 years 1 month 6 days
Energy | 5.25% senior unsecured notes due 2025
Accounting Policies [Line Items]
Interest rate on debt instrument	5.25%	5.25%
Energy | Reserved Funds [Member]
Accounting Policies [Line Items]
Cash and cash equivalents	$ 598	$ 598
Energy | Minimum | Refineries
Accounting Policies [Line Items]
Turnaround Term of Plants		4 years
Energy | Maximum | Refineries
Accounting Policies [Line Items]
Turnaround Term of Plants		5 years
Energy | Maximum | Nitrogen Fertilizer Plants
Accounting Policies [Line Items]
Turnaround Term of Plants		3 years
Automotive Segment
Accounting Policies [Line Items]
Total assets	2,019	$ 2,019	$ 2,532
Debt	33	33	21
Cash and cash equivalents	104	104	32
Restricted cash	9	9	10
Deferred revenue	45	45	44
Impairment	$ 7
Recorded revenue		$ 22	$ 25	$ 24
Lease term	5 years 4 months 24 days	5 years 4 months 24 days	4 years 8 months 12 days
Real Estate Segment
Accounting Policies [Line Items]
Total assets	$ 488	$ 488	$ 507
Debt	1	1	1
Cash and cash equivalents	22	22	26
Restricted cash	$ 4	$ 4	$ 8
Real Estate Segment | Minimum
Accounting Policies [Line Items]
Lease term	5 years	5 years
Real Estate Segment | Maximum
Accounting Policies [Line Items]
Lease term	39 years	39 years
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Accounting Policies [Line Items]
Remaining performance obligation for contracts with an original expected duration of more than one year	1 year	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 | Energy
Accounting Policies [Line Items]
Remaining performance obligation expected to be recognized as revenue within one year	$ 3	$ 3
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Accounting Policies [Line Items]
Remaining performance obligation for contracts with an original expected duration of more than one year	2 years	2 years
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01 | Energy
Accounting Policies [Line Items]
Remaining performance obligation for contracts with an original expected duration of more than one year	$ 3	$ 3