v3.26.1
Investments (Details) - Investment Information, Debt Securities - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Dec. 31, 2025
Dec. 31, 2024
Investment disclosure details        
Fixed maturities, amortized cost $ 93,742   $ 91,717  
Allowance for expected credit losses 3   3  
Gross unrealized gains 524   968  
Gross unrealized losses 3,527   2,849  
Fixed maturities, at fair value 90,736   89,833  
Proceeds from sales of fixed maturities classified as available for sale 251 $ 253    
Gross realized gains 1 1    
Gross realized losses on sales of fixed maturities 19 12    
Realized losses resulting from the early redemption of fixed maturities by the issuer prior to the bonds' maturity date 0 18    
Amounts classified as held for sale [Member]        
Investment disclosure details        
Fixed maturities, amortized cost     3,221  
Fixed maturities, at fair value     3,243  
U.S. Treasury securities and obligations of U.S. government and government agencies and authorities [Member]        
Investment disclosure details        
Fixed maturities, amortized cost 3,475   3,927  
Allowance for expected credit losses 0   0  
Gross unrealized gains 2   11  
Gross unrealized losses 94   81  
Fixed maturities, at fair value 3,383   3,857  
Obligations of U.S. states, municipalities and political subdivisions [Member]        
Investment disclosure details        
Fixed maturities, amortized cost 33,924   32,819  
Allowance for expected credit losses 0   0  
Gross unrealized gains 134   229  
Gross unrealized losses 2,078   1,670  
Fixed maturities, at fair value 31,980   31,378  
Obligations of U.S. states, municipalities and political subdivisions, local general obligation [Member]        
Investment disclosure details        
Fixed maturities, amortized cost 22,523   21,724  
Allowance for expected credit losses 0   0  
Gross unrealized gains 93   161  
Gross unrealized losses 1,394   1,096  
Fixed maturities, at fair value 21,222   20,789  
Obligations of U.S. states, municipalities and political subdivisions, revenue [Member]        
Investment disclosure details        
Fixed maturities, amortized cost 10,171   9,810  
Allowance for expected credit losses 0   0  
Gross unrealized gains 35   58  
Gross unrealized losses 645   543  
Fixed maturities, at fair value 9,561   9,325  
Obligations of U.S. states, municipalities and political subdivisions, state general obligation [Member]        
Investment disclosure details        
Fixed maturities, amortized cost 861   871  
Allowance for expected credit losses 0   0  
Gross unrealized gains 3   6  
Gross unrealized losses 36   29  
Fixed maturities, at fair value 828   848  
Obligations of U.S. states, municipalities and political subdivisions, pre-refunded [Member]        
Investment disclosure details        
Fixed maturities, amortized cost 369   414  
Allowance for expected credit losses 0   0  
Gross unrealized gains 3   4  
Gross unrealized losses 3   2  
Fixed maturities, at fair value 369   416  
Debt securities issued by foreign governments [Member]        
Investment disclosure details        
Fixed maturities, amortized cost 362   313  
Allowance for expected credit losses 0   0  
Gross unrealized gains 1   2  
Gross unrealized losses 5   3  
Fixed maturities, at fair value 358   312  
Mortgage-backed securities, collateralized mortgage obligations and pass-through securities [Member]        
Investment disclosure details        
Fixed maturities, amortized cost 12,839   13,094  
Allowance for expected credit losses 0   0  
Gross unrealized gains 165   268  
Gross unrealized losses 156   130  
Fixed maturities, at fair value 12,848   13,232  
Corporate and all other bonds [Member]        
Investment disclosure details        
Fixed maturities, amortized cost 43,142   41,564  
Allowance for expected credit losses 3 $ 4 3 $ 2
Gross unrealized gains 222   458  
Gross unrealized losses 1,194   965  
Fixed maturities, at fair value $ 42,167   $ 41,054