v3.24.2
Insurance Claim Reserves (Details) - Reserve Detail for Claims and Claim Adjustment Expenses - USD ($)
$ in Millions
 6 Months Ended
Jun. 30, 2024
Jun. 30, 2023
Reconciliation of beginning and ending reserve balances for claims and claim adjustment expenses [Roll Forward]    
Claims and claim adjustment expense reserves at beginning of year $ 61,627  
Claims and claim adjustment expense reserves at end of period 63,857  
Property-casualty [Member]    
Reconciliation of beginning and ending reserve balances for claims and claim adjustment expenses [Roll Forward]    
Claims and claim adjustment expense reserves at beginning of year 61,621 $ 58,643
Reinsurance recoverables on unpaid losses 7,817 7,790
Net reserves at beginning of year 53,804 50,853
Estimated claims and claim adjustment expenses for claims arising in the current year 14,213 13,260
Estimated decrease in claims and claim adjustment expenses for claims arising in prior years (232) (118)
Total increases 13,981 13,142
Claims and claim adjustment expense payments for claims arising in current year 3,953 3,898
Claims and claim adjustment expense payments for claims arising in prior years 7,750 7,466
Total payments 11,703 11,364
Unrealized foreign exchange (gain) loss (75) 104
Net reserves at end of period 56,007 52,735
Reinsurance recoverables on unpaid losses 7,845 7,829
Claims and claim adjustment expense reserves at end of period 63,852 $ 60,564
Amount of increase in gross claims and claim adjustment expense reserves 2,230  
Amount of increase in reinsurance recoverables on unpaid losses 28  
Accident and health [Member]    
Reconciliation of beginning and ending reserve balances for claims and claim adjustment expenses [Roll Forward]    
Claims and claim adjustment expense reserves at beginning of year 6  
Claims and claim adjustment expense reserves at end of period $ 5