v3.25.4
RESERVE FOR LOSSES AND LAE - Schedule of Reconciliation Of Change In Net Ultimate Loss And Loss Adjustment Expense To Prior Year Development (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Short-Duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]      
Prior Year Development Net of External Reinsurance Before ADC Cessions $ 389    
Prior Year Development Net of External Reinsurance After ADC Cessions 657 $ 1,300 $ (5)
Excess compensation for the uncertainty of future claims development 122    
Insurance      
Short-Duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]      
Excess compensation for the uncertainty of future claims development 105    
Other      
Short-Duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]      
Prior Year Development Net of External Reinsurance After ADC Cessions 146    
Excess compensation for the uncertainty of future claims development 17    
Casualty Insurance | Reinsurance      
Short-Duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]      
Prior Year Development Net of External Reinsurance Before ADC Cessions 456    
Casualty Insurance | Insurance      
Short-Duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]      
Prior Year Development Net of External Reinsurance Before ADC Cessions 474    
Property Insurance | Reinsurance      
Short-Duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]      
Prior Year Development Net of External Reinsurance Before ADC Cessions (428)    
Property Insurance | Insurance      
Short-Duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]      
Prior Year Development Net of External Reinsurance Before ADC Cessions $ (113)