v3.24.2.u1
Insurance Contracts - Summary of Loss Reserve Roll-Forward, Net of Subrogation Recoverable and Reinsurance (Details) - USD ($)
$ in Millions
 6 Months Ended
Jun. 30, 2024
Jun. 30, 2023
Dec. 31, 2023
Dec. 31, 2022
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]        
Beginning balance of net loss and loss expense reserves $ 570 $ 419    
Current Year Claims and Claims Adjustment Expense 40 8    
Prior Year Claims and Claims Adjustment Expense (23) 18    
Liability for Unpaid Claims and Claims Adjustment Expense, Incurred Claims 17 25    
Claim and loss expense payments, net of subrogation and reinsurance (3) (1)    
Claim and loss expense (payments) recoveries, net of subrogation and reinsurance (63) 136    
Liability for Unpaid Claims and Claims Adjustment Expense, Claims Paid 66 (135)    
Liability for Unpaid Claims and Claims Adjustment Expense, Foreign Currency Translation Gain (Loss) 0 0    
Liability for Unpaid Claims and Claims Adjustment Expense, Net 520 580 $ 570 $ 419
Reinsurance Recoverable for Unpaid Claims and Claims Adjustments 242 144 186 115
Policyholder Benefits and Claims Incurred, Ceded 98 45    
Ceded Loss And Loss Expenses Paid Not Yet Recovered   5    
Liability for Claim and Claim Adjustment Expenses Net of Subrogation recoverables 762 $ 724 756 $ 534
Financial Guarantee        
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]        
Ceded Loss And Loss Expenses Paid Not Yet Recovered 0   (1)  
Loss Reserves Ceded To Reinsurers $ 26   $ 30