v3.26.3
RESERVE FOR LOSSES AND LAE - Schedule of Activity in the Reserve for Losses and LAE (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Dec. 31, 2025
Dec. 31, 2024
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]            
Gross reserves beginning of period     $ 34,312 $ 29,889 $ 29,889  
Less reinsurance recoverables on unpaid losses $ (3,616) $ (3,511) (3,616) (3,511) (3,715) $ (2,915)
Net reserves beginning of period     30,597 26,975 26,975  
Incurred related to:            
Current year     6,585 7,665    
Prior years     226 537    
Prior years, reserves subject to the ADC 0 0 8 0    
Total incurred losses and LAE     6,819 8,203    
Paid related to:            
Current year     770 885    
Prior years     4,804 4,670    
Total paid losses and LAE     5,574 5,554    
Foreign exchange/translation adjustment     (170) 607    
Net reserves end of period 31,672 30,231 31,672 30,231 30,597  
Plus reinsurance recoverables on unpaid losses 3,616 3,511 3,616 3,511 3,715 $ 2,915
Gross reserves end of period 35,288 $ 33,742 35,288 $ 33,742 34,312  
Reinsurance recoverables, adverse development reinsurance agreement 1,300   1,300   1,300  
Wildfires and Other Weather Related Events            
Incurred related to:            
Current year     243      
Reinsurance Contract [Axis]: Adverse Development Cover Reinsurance Agreements            
Paid related to:            
Policyholder benefits and claims incurred, ceded     1,260   $ 1,300  
Reinsurance recoverables, adverse development reinsurance agreement $ 1,260   $ 1,260