v3.26.3
Investments - Fixed Maturity Securities and Short Term Investments (Details) - USD ($)
$ in Millions
Sep. 30, 2026
Jun. 30, 2026
Dec. 31, 2025
Sep. 30, 2025
Jun. 30, 2025
Dec. 31, 2024
Schedule of Investments [Line Items]            
Percent of Total 100.00%   100.00%      
Amortized Cost $ 7,135   $ 6,572      
Allowance for Credit Losses (82) $ (72) (54) $ (54) $ (47) $ (60)
Gross Unrealized Gains 41   135      
Gross Unrealized Losses (588)   (284)      
Fixed-maturity securities, available for sale $ 6,506   $ 6,369      
Government agency obligations as a percentage of total mortgage backed securities 70.00%   75.00%      
Obligations of state and political subdivisions            
Schedule of Investments [Line Items]            
Percent of Total 21.00%   28.00%      
Amortized Cost $ 1,486   $ 1,816      
Allowance for Credit Losses (14)   (13)      
Gross Unrealized Gains 19   37      
Gross Unrealized Losses (141)   (71)      
Fixed-maturity securities, available for sale $ 1,350   $ 1,769      
U.S. government and agencies            
Schedule of Investments [Line Items]            
Percent of Total 1.00%   1.00%      
Amortized Cost $ 49   $ 55      
Allowance for Credit Losses 0   0      
Gross Unrealized Gains 0   1      
Gross Unrealized Losses (6)   (4)      
Fixed-maturity securities, available for sale $ 43   $ 52      
Corporate securities            
Schedule of Investments [Line Items]            
Percent of Total 50.00%   46.00%      
Amortized Cost $ 3,545   $ 2,998      
Allowance for Credit Losses (11)   (6)      
Gross Unrealized Gains 14   75      
Gross Unrealized Losses (272)   (115)      
Fixed-maturity securities, available for sale $ 3,276   $ 2,952      
RMBS            
Schedule of Investments [Line Items]            
Percent of Total 11.00%   10.00%      
Amortized Cost $ 778   $ 678      
Allowance for Credit Losses (29)   (26)      
Gross Unrealized Gains 2   10      
Gross Unrealized Losses (62)   (47)      
Fixed-maturity securities, available for sale $ 689   $ 615      
CMBS            
Schedule of Investments [Line Items]            
Percent of Total 4.00%   3.00%      
Amortized Cost $ 276   $ 197      
Allowance for Credit Losses 0   0      
Gross Unrealized Gains 0   2      
Gross Unrealized Losses (10)   (1)      
Fixed-maturity securities, available for sale $ 266   $ 198      
CLOs            
Schedule of Investments [Line Items]            
Percent of Total 7.00%   7.00%      
Amortized Cost $ 514   $ 499      
Allowance for Credit Losses (28)   (9)      
Gross Unrealized Gains 4   4      
Gross Unrealized Losses (67)   (38)      
Fixed-maturity securities, available for sale $ 423   $ 456      
Others            
Schedule of Investments [Line Items]            
Percent of Total 3.00%   3.00%      
Amortized Cost $ 238   $ 206      
Allowance for Credit Losses 0   0      
Gross Unrealized Gains 2   3      
Gross Unrealized Losses (5)   0      
Fixed-maturity securities, available for sale 235   209      
Others | Affiliated Entity            
Schedule of Investments [Line Items]            
Amortized Cost 59   53      
Fixed-maturity securities, available for sale $ 61   $ 54      
Non-U.S. government securities            
Schedule of Investments [Line Items]            
Percent of Total 3.00%   2.00%      
Amortized Cost $ 249   $ 123      
Allowance for Credit Losses 0   0      
Gross Unrealized Gains 0   3      
Gross Unrealized Losses (25)   (8)      
Fixed-maturity securities, available for sale $ 224   $ 118