v3.24.2.u1
Loss and Loss Adjustment Expense Reserves (Schedule of Losses and Loss Adjustment Expenses Reserves and Recoveries) (Detail) - USD ($)
$ in Millions
Jun. 30, 2024
Dec. 31, 2023
Loss And Lae Reserves [Member]    
Loss And Loss Adjustment Expense Reserves [Line Items]    
Loss and loss adjustment expense reserves [1] $ 577 $ 473
Insurance Loss Recoverable [Member]    
Loss And Loss Adjustment Expense Reserves [Line Items]    
Insurance Loss Recoverable 142 183
Non Variable Interest Entity [Member]    
Loss And Loss Adjustment Expense Reserves [Line Items]    
Insurance Loss Recoverable 142 183
Loss and loss adjustment expense reserves 577 473
US Public Finance Insurance [Member]    
Loss And Loss Adjustment Expense Reserves [Line Items]    
Insurance Loss Recoverable 114 152
Loss and loss adjustment expense reserves [1] 344 230
International And Structured Finance Insurance [Member]    
Loss And Loss Adjustment Expense Reserves [Line Items]    
Insurance Loss Recoverable 29 32
Loss and loss adjustment expense reserves [1] 242 335
International And Structured Finance Insurance [Member] | Non Variable Interest Entity [Member]    
Loss And Loss Adjustment Expense Reserves [Line Items]    
Insurance Loss Recoverable 28 31
Loss and loss adjustment expense reserves [1] 233 243
Consolidation Elimination [Member] | International And Structured Finance Insurance [Member] | Variable Interest Entity, Primary Beneficiary [Member]    
Loss And Loss Adjustment Expense Reserves [Line Items]    
Insurance Loss Recoverable (1) (1)
Loss and loss adjustment expense reserves [1] $ (9) $ (92)
[1] Amounts are net of estimated recoveries of expected future claims.