Basis of Presentation and Summary of Significant Accounting Policies (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023	Feb. 29, 2024	Mar. 31, 2023	Dec. 31, 2022
Accounting Policies [Line Items]
Total assets	$ 20,064	$ 20,858
Debt	6,608	7,207
Fair value of long-term debt	6,400	6,900
Cash and cash equivalents	2,468	2,951
Restricted cash	2,565	2,995
Accumulated other comprehensive loss	$ (57)	(55)		$ (66)	$ (70)
Icahn Enterprises G.P.
Accounting Policies [Line Items]
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%
Cash held at consolidated affiliated partnerships
Accounting Policies [Line Items]
Restricted cash	$ 791	1,068
Restricted cash
Accounting Policies [Line Items]
Restricted cash	1,774	1,927
Primary beneficiary
Accounting Policies [Line Items]
Total assets	104
Energy
Accounting Policies [Line Items]
Total assets	4,629	5,259
Debt	1,585	2,185
Cash and cash equivalents	644	1,179
Restricted cash		7
Remaining performance obligation expected to be recognized as revenue within one year	14
Remaining performance obligation expected to be recognized as revenue within one year	4
Remaining performance obligation for contracts with an original expected duration of more than one year	5
Deferred revenue	52	49
Recorded revenue	$ 5	$ 12
Lease term	5 years 3 months 18 days	5 years 4 months 24 days
Energy | 5.25% senior unsecured notes due 2025
Accounting Policies [Line Items]
Interest rate on debt instrument			5.25%
Automotive Segment
Accounting Policies [Line Items]
Total assets	$ 1,958	$ 2,019
Debt	29	33
Cash and cash equivalents	64	104
Restricted cash	8	9
Deferred revenue	43	45
Recorded revenue	$ 6	$ 6
Lease term	5 years 3 months 18 days	5 years 4 months 24 days
Real Estate Segment
Accounting Policies [Line Items]
Total assets	$ 501	$ 488
Debt	1	1
Cash and cash equivalents	33	22
Restricted cash	$ 4	$ 4