v3.26.1
Investments - Fixed Maturities and Equity Securities (Details) - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Dec. 31, 2024
Available-for-sale Securities Including Securities Pledged [Line Items]      
Debt Securities, Available-for-Sale, Amortized Cost, Excluding Accrued Interest, before Allowance for Credit Loss $ 21,969 $ 22,083  
Available-for-sale Securities, Pledged as Collateral, Debt Securities, Amortized Cost 1,053 959  
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Excluding Accrued Interest 13 17 $ 30
Collateral Pledged      
Available-for-sale Securities Including Securities Pledged [Line Items]      
Securities pledged 937 845  
U.S. Treasuries      
Available-for-sale Securities Including Securities Pledged [Line Items]      
Debt Securities, Available-for-Sale, Amortized Cost, Excluding Accrued Interest, before Allowance for Credit Loss 581 517  
Fixed maturities, Gross Unrealized Capital Gains 0 0  
Fixed maturities, Gross Unrealized Capital Losses 54 47  
Embedded Derivatives 0 0  
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Excluding Accrued Interest 0 0  
Debt Securities, Available-for-Sale, Excluding Accrued Interest 527 470  
US Government Agencies Debt Securities      
Available-for-sale Securities Including Securities Pledged [Line Items]      
Debt Securities, Available-for-Sale, Amortized Cost, Excluding Accrued Interest, before Allowance for Credit Loss 29 29  
Fixed maturities, Gross Unrealized Capital Gains 0 0  
Fixed maturities, Gross Unrealized Capital Losses 1 1  
Embedded Derivatives 0 0  
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Excluding Accrued Interest 0 0  
Debt Securities, Available-for-Sale, Excluding Accrued Interest 28 28  
State, municipalities and political subdivisions      
Available-for-sale Securities Including Securities Pledged [Line Items]      
Debt Securities, Available-for-Sale, Amortized Cost, Excluding Accrued Interest, before Allowance for Credit Loss 382 427  
Fixed maturities, Gross Unrealized Capital Gains 0 0  
Fixed maturities, Gross Unrealized Capital Losses 64 68  
Embedded Derivatives 0 0  
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Excluding Accrued Interest 0 0  
Debt Securities, Available-for-Sale, Excluding Accrued Interest 318 359  
Debt Security, Corporate, US      
Available-for-sale Securities Including Securities Pledged [Line Items]      
Debt Securities, Available-for-Sale, Amortized Cost, Excluding Accrued Interest, before Allowance for Credit Loss 6,962 6,701  
Fixed maturities, Gross Unrealized Capital Gains 59 84  
Fixed maturities, Gross Unrealized Capital Losses 808 773  
Embedded Derivatives 0 0  
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Excluding Accrued Interest 0 0  
Debt Securities, Available-for-Sale, Excluding Accrued Interest 6,213 6,012  
Private Equity Funds, US      
Available-for-sale Securities Including Securities Pledged [Line Items]      
Debt Securities, Available-for-Sale, Amortized Cost, Excluding Accrued Interest, before Allowance for Credit Loss 4,576 4,578  
Fixed maturities, Gross Unrealized Capital Gains 33 66  
Fixed maturities, Gross Unrealized Capital Losses 186 165  
Embedded Derivatives 0 0  
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Excluding Accrued Interest 1 6 3
Debt Securities, Available-for-Sale, Excluding Accrued Interest 4,422 4,473  
Foreign corporate public securities and foreign governments      
Available-for-sale Securities Including Securities Pledged [Line Items]      
Debt Securities, Available-for-Sale, Amortized Cost, Excluding Accrued Interest, before Allowance for Credit Loss 2,314 2,292  
Fixed maturities, Gross Unrealized Capital Gains 29 43  
Fixed maturities, Gross Unrealized Capital Losses 181 177  
Embedded Derivatives 0 0  
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Excluding Accrued Interest 1 1 1
Debt Securities, Available-for-Sale, Excluding Accrued Interest 2,161 2,157  
Private Equity Funds, Non-US      
Available-for-sale Securities Including Securities Pledged [Line Items]      
Debt Securities, Available-for-Sale, Amortized Cost, Excluding Accrued Interest, before Allowance for Credit Loss 2,210 2,250  
Fixed maturities, Gross Unrealized Capital Gains 27 45  
Fixed maturities, Gross Unrealized Capital Losses 51 39  
Embedded Derivatives 0 0  
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Excluding Accrued Interest 8 8 8
Debt Securities, Available-for-Sale, Excluding Accrued Interest 2,178 2,248  
Residential mortgage-backed      
Available-for-sale Securities Including Securities Pledged [Line Items]      
Debt Securities, Available-for-Sale, Amortized Cost, Excluding Accrued Interest, before Allowance for Credit Loss 3,175 3,287  
Fixed maturities, Gross Unrealized Capital Gains 28 41  
Fixed maturities, Gross Unrealized Capital Losses 98 92  
Embedded Derivatives 3 1  
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Excluding Accrued Interest 0 0  
Debt Securities, Available-for-Sale, Excluding Accrued Interest 3,102 3,237  
Commercial mortgage-backed      
Available-for-sale Securities Including Securities Pledged [Line Items]      
Debt Securities, Available-for-Sale, Amortized Cost, Excluding Accrued Interest, before Allowance for Credit Loss 1,880 2,115  
Fixed maturities, Gross Unrealized Capital Gains 3 5  
Fixed maturities, Gross Unrealized Capital Losses 234 241  
Embedded Derivatives 0 0  
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Excluding Accrued Interest 0 0 17
Debt Securities, Available-for-Sale, Excluding Accrued Interest 1,649 1,879  
Other asset-backed securities      
Available-for-sale Securities Including Securities Pledged [Line Items]      
Debt Securities, Available-for-Sale, Amortized Cost, Excluding Accrued Interest, before Allowance for Credit Loss 1,926 1,977  
Fixed maturities, Gross Unrealized Capital Gains 20 17  
Fixed maturities, Gross Unrealized Capital Losses 22 17  
Embedded Derivatives 0 0  
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Excluding Accrued Interest 3 2 $ 1
Debt Securities, Available-for-Sale, Excluding Accrued Interest 1,921 1,975  
Embedded derivatives within fixed maturities      
Available-for-sale Securities Including Securities Pledged [Line Items]      
Debt Securities, Available-for-Sale, Amortized Cost, Excluding Accrued Interest, before Allowance for Credit Loss 24,035 24,173  
Total fixed maturities, less securities pledged, Amortized Cost 22,982 23,214  
Fixed maturities, Gross Unrealized Capital Gains 199 301  
Total fixed maturities, less securities pledged, Gross Unrealized Capital Gains 199 301  
Fixed maturities, Gross Unrealized Capital Losses 1,699 1,620  
Embedded Derivatives (3) 1  
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Excluding Accrued Interest 13 17  
Debt Securities, Available-for-Sale, Excluding Accrued Interest 22,519 22,838  
Total fixed maturities, less securities pledged, Fair Value 21,582 21,993  
Available-for-sale Securities, Less Securities Pledged, Debt Securities, Unrecognized Holding Loss 1,583 1,506  
Embedded derivatives within fixed maturities | Collateral Pledged      
Available-for-sale Securities Including Securities Pledged [Line Items]      
Available-for-sale Securities, Pledged as Collateral, Debt Securities, Amortized Cost 1,053 959  
Securities pledged, Gross Unrealized Capital Gains 0 0  
Available-for-sale Securities, Pledged as Collateral, Debt Securities, Unrecognized Holding Loss 116 114  
Embedded Derivatives 0 0  
Debt Securities, Available-for-Sale, Allowance for Credit Loss, Excluding Accrued Interest 0 0  
Securities pledged $ 937 $ 845