v3.26.1
Basis of Presentation and Summary of Significant Accounting Policies (Details) - USD ($)
$ in Millions
 3 Months Ended 12 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Dec. 31, 2025
Accounting Policies [Line Items]      
Total Assets $ 12,933   $ 14,215
Debt 6,392   6,616
Fair value of long-term debt 6,200   6,300
Restricted cash 1,995   1,969
TEB LLC      
Accounting Policies [Line Items]      
Carrying amount of equity method investment 81   74
Carrying value of equity investment and related party loan receivable $ 213   203
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 $ 782   746
Restricted cash      
Accounting Policies [Line Items]      
Restricted cash 1,200   1,200
Primary beneficiary      
Accounting Policies [Line Items]      
Total Assets 114   113
Energy      
Accounting Policies [Line Items]      
Total Assets 4,268   4,129
Debt 1,784   1,765
Remaining performance obligation expected to be recognized as revenue within one year 2    
Deferred revenue 43   44
Recorded revenue 12 $ 23  
Automotive Segment      
Accounting Policies [Line Items]      
Total Assets 1,298   1,248
Debt 26   21
Restricted cash 8   8
Deferred revenue 26   $ 28
Recorded revenue $ 5 $ 6  
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-10-01      
Accounting Policies [Line Items]      
Remaining performance obligation for contracts with an original expected duration of more than one year 9 months    
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-10-01 | Energy      
Accounting Policies [Line Items]      
Remaining performance obligation expected to be recognized as revenue within one year $ 2    
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-01-01      
Accounting Policies [Line Items]      
Remaining performance obligation for contracts with an original expected duration of more than one year 1 year    
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-01-01 | Energy | Maximum      
Accounting Policies [Line Items]      
Remaining performance obligation for contracts with an original expected duration of more than one year $ 1