v3.26.1
Reserve for Property and Casualty Insurance Claims and Claims Expense - Schedule of Rollforward of the Reserve for Property and Casualty Insurance Claims and Claims Expense (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Dec. 31, 2024
Property-liability insurance claims and claims expense            
Beginning balance     $ 41,079      
Incurred claims and claims expense related to:            
Prior years $ (641) $ (370) (1,645) $ (621)    
Claims and claims expense paid related to:            
Ending balance 40,979   40,979      
Property and casualty            
Property-liability insurance claims and claims expense            
Beginning balance     41,079 41,917    
Less: recoverables 7,446 9,285 7,446 9,285 $ 8,012 $ 8,602
Activity in the reserve for property-liability insurance claims and claims expense:            
Net beginning balance     33,067 33,315    
Incurred claims and claims expense related to:            
Current year     20,692 21,685    
Prior years     (1,645) (621)    
Total incurred     19,047 21,064    
Claims and claims expense paid related to:            
Current year     (9,320) (10,002)    
Prior years     (9,261) (9,521)    
Total paid     (18,581) (19,523)    
Net ending balance 33,533 34,856 33,533 34,856    
Plus: recoverables 7,446 9,285 7,446 9,285 $ 8,012 $ 8,602
Ending balance $ 40,979 $ 44,141 $ 40,979 $ 44,141