v3.25.2
Claim and Claim Adjustment Expense Reserves - Reconciliation of Claim and Claim Adjustment Expense Reserves (Details) - USD ($)
$ in Millions
6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]    
Gross reserves, beginning of year $ 24,976 $ 23,304
Ceded reserves, beginning of year 5,713 5,141
Net reserves, beginning of year 19,263 18,163
Net incurred claim and claim adjustment expenses:    
Provision for insured events of current year 3,309 3,039
Increase (decrease) in provision for insured events of prior years 189 19
Amortization of discount 20 20
Total net incurred 3,518 3,078
Net payments attributable to:    
Current year events (316) (308)
Prior year events (2,391) (2,259)
Total net payments (2,707) (2,567)
Foreign currency translation adjustment and other 199 (58)
Net reserves, end of period 20,273 18,616
Ceded reserves, end of period 5,930 5,358
Gross reserves, end of period $ 26,203 $ 23,974