v3.26.3
Investments (Details) - Investment Information, Debt Securities - USD ($)
$ in Millions
 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Jun. 30, 2026
Dec. 31, 2025
Jun. 30, 2025
Dec. 31, 2024
Investment disclosure details            
Fixed maturities, amortized cost $ 97,423     $ 91,717    
Allowance for expected credit losses 2     3    
Gross unrealized gains 29     968    
Gross unrealized losses 8,078     2,849    
Fixed maturities, at fair value 89,372     89,833    
Proceeds from sales of fixed maturities classified as available for sale 917 $ 779        
Gross realized gains 1 1        
Gross realized losses on sales of fixed maturities 45 29        
Realized losses resulting from the early redemption of fixed maturities by the issuer prior to the bonds' maturity date 15 20        
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 3,267     3,927    
Allowance for expected credit losses 0     0    
Gross unrealized gains 0     11    
Gross unrealized losses 245     81    
Fixed maturities, at fair value 3,022     3,857    
Obligations of U.S. states, municipalities and political subdivisions [Member]            
Investment disclosure details            
Fixed maturities, amortized cost 35,018     32,819    
Allowance for expected credit losses 0     0    
Gross unrealized gains 4     229    
Gross unrealized losses 4,481     1,670    
Fixed maturities, at fair value 30,541     31,378    
Obligations of U.S. states, municipalities and political subdivisions, local general obligation [Member]            
Investment disclosure details            
Fixed maturities, amortized cost 23,649     21,724    
Allowance for expected credit losses 0     0    
Gross unrealized gains 1     161    
Gross unrealized losses 3,084     1,096    
Fixed maturities, at fair value 20,566     20,789    
Obligations of U.S. states, municipalities and political subdivisions, revenue [Member]            
Investment disclosure details            
Fixed maturities, amortized cost 10,306     9,810    
Allowance for expected credit losses 0     0    
Gross unrealized gains 2     58    
Gross unrealized losses 1,302     543    
Fixed maturities, at fair value 9,006     9,325    
Obligations of U.S. states, municipalities and political subdivisions, state general obligation [Member]            
Investment disclosure details            
Fixed maturities, amortized cost 816     871    
Allowance for expected credit losses 0     0    
Gross unrealized gains 1     6    
Gross unrealized losses 89     29    
Fixed maturities, at fair value 728     848    
Obligations of U.S. states, municipalities and political subdivisions, pre-refunded [Member]            
Investment disclosure details            
Fixed maturities, amortized cost 247     414    
Allowance for expected credit losses 0     0    
Gross unrealized gains 0     4    
Gross unrealized losses 6     2    
Fixed maturities, at fair value 241     416    
Debt securities issued by foreign governments [Member]            
Investment disclosure details            
Fixed maturities, amortized cost 420     313    
Allowance for expected credit losses 0     0    
Gross unrealized gains 0     2    
Gross unrealized losses 12     3    
Fixed maturities, at fair value 408     312    
Mortgage-backed securities, collateralized mortgage obligations and pass-through securities [Member]            
Investment disclosure details            
Fixed maturities, amortized cost 13,232     13,094    
Allowance for expected credit losses 0     0    
Gross unrealized gains 8     268    
Gross unrealized losses 733     130    
Fixed maturities, at fair value 12,507     13,232    
Corporate and all other bonds [Member]            
Investment disclosure details            
Fixed maturities, amortized cost 45,486     41,564    
Allowance for expected credit losses 2 $ 4 $ 2 3 $ 4 $ 2
Gross unrealized gains 17     458    
Gross unrealized losses 2,607     965    
Fixed maturities, at fair value $ 42,894     $ 41,054