v3.26.1
Unpaid losses and loss expenses (RF) (Details) - USD ($)
$ in Millions
 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Liability for Claims and Claims Adjustment Expense [Line Items]    
Gross unpaid losses and loss expenses – beginning of period $ 88,018 $ 84,004
Reinsurance recoverable on unpaid losses and loss expenses - beginning of period [1] 18,346 17,734
Net unpaid losses and loss expenses – beginning of period 69,672 66,270
Current Year Claims and Claims Adjustment Expense 13,406 13,959
Prior Year Claims and Claims Adjustment Expense [2] (584) (491)
Total, Incurred 12,822 13,468
Net loss and loss expenses paid, Current Year 3,169 2,960
Net loss and loss expenses paid, Prior Years 8,184 8,982
Total, Paid 11,353 11,942
Foreign currency revaluation and other 75 889
Net unpaid losses and loss expenses – end of period 71,216 68,685
Reinsurance recoverable on unpaid losses and loss expenses - end of period [1] (18,453) (17,691)
Gross unpaid losses and loss expenses – end of period 89,669 86,376
prior period development, net adjustments $ 15 $ (13)
[1] Net of valuation allowance for uncollectible reinsurance.
[2] Relates to prior period loss reserve development only and excludes prior period development related to reinstatement premiums, expense adjustments, earned premiums, and A&H long-duration lines totaling $15 million and $(13) million for the six months ended June 30, 2026 and 2025, respectively.