v3.26.1
Reserve for Losses and Loss Adjustment Expenses - Reconciliation of beginning and ending balances of losses and loss adjustment reserves (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Liability for Future Policy Benefits and Unpaid Claims and Claims Adjustment Expense [Abstract]        
Reserve for losses and loss adjustment expenses at beginning of period $ 34,105 $ 30,946 $ 33,547 $ 29,369
Unpaid losses and loss adjustment expenses recoverable 9,142 8,379 9,054 7,821
Net reserve for losses and loss adjustment expenses at beginning of period 24,963 22,567 24,493 21,548
Net incurred losses and loss adjustment expenses relating to losses occurring in:        
Current year 2,365 2,456 4,674 5,240
Prior years (169) (153) (389) (350)
Total net incurred losses and loss adjustment expenses 2,196 2,303 4,285 4,890
Net losses and loss adjustment expense reserves of acquired business [1] 0 50 0 50
Net foreign exchange (gains) losses and other 2 400 (68) 593
Net paid losses and loss adjustment expenses relating to losses occurring in:        
Current year (269) (424) (329) (865)
Prior years (1,428) (1,320) (2,917) (2,640)
Total net paid losses and loss adjustment expenses (1,697) (1,744) (3,246) (3,505)
Net reserve for losses and loss adjustment expenses at end of period 25,464 23,576 25,464 23,576
Unpaid losses and loss adjustment expenses recoverable 9,311 8,513 9,311 8,513
Reserve for losses and loss adjustment expenses at end of period $ 34,775 $ 32,089 $ 34,775 $ 32,089
[1] Activity in the 2025 periods related to the MCE Acquisition (see note 2).