v3.25.2
Investments (Details) - Investment Information, Losses - USD ($)
$ in Millions
Jun. 30, 2025
Dec. 31, 2024
Investment disclosure details    
Continuous unrealized loss position, less than 12 months, fair value $ 16,728 $ 23,954
Continuous unrealized loss position, less than 12 months, gross unrealized losses 496 454
Continuous unrealized loss position, 12 months or longer, fair value 39,375 41,709
Continuous unrealized loss position, 12 months or longer, gross unrealized losses 3,857 4,378
Continuous unrealized loss position, total, fair value 56,103 65,663
Continuous unrealized loss position, total, gross unrealized losses 4,353 4,832
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, 3 months or less 63 437
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost greater than 3 months, 6 months or less 254 0
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, greater than 6 months, 12 months or less 149 43
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, greater than 12 months 733 638
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, total 1,199 1,118
U.S. Treasury securities and obligations of U.S. government and government agencies and authorities [Member]    
Investment disclosure details    
Continuous unrealized loss position, less than 12 months, fair value 566 557
Continuous unrealized loss position, less than 12 months, gross unrealized losses 0 1
Continuous unrealized loss position, 12 months or longer, fair value 2,248 2,830
Continuous unrealized loss position, 12 months or longer, gross unrealized losses 99 168
Continuous unrealized loss position, total, fair value 2,814 3,387
Continuous unrealized loss position, total, gross unrealized losses 99 169
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, 3 months or less 0 0
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost greater than 3 months, 6 months or less 0 0
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, greater than 6 months, 12 months or less 0 0
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, greater than 12 months 0 0
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, total 0 0
Obligations of U.S. states, municipalities and political subdivisions [Member]    
Investment disclosure details    
Continuous unrealized loss position, less than 12 months, fair value 9,403 8,584
Continuous unrealized loss position, less than 12 months, gross unrealized losses 411 160
Continuous unrealized loss position, 12 months or longer, fair value 15,223 15,007
Continuous unrealized loss position, 12 months or longer, gross unrealized losses 2,350 2,224
Continuous unrealized loss position, total, fair value 24,626 23,591
Continuous unrealized loss position, total, gross unrealized losses 2,761 2,384
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, 3 months or less 56 366
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost greater than 3 months, 6 months or less 248 0
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, greater than 6 months, 12 months or less 149 43
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, greater than 12 months 732 635
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, total 1,185 1,044
Debt securities issued by foreign governments [Member]    
Investment disclosure details    
Continuous unrealized loss position, less than 12 months, fair value 93 113
Continuous unrealized loss position, less than 12 months, gross unrealized losses 0 1
Continuous unrealized loss position, 12 months or longer, fair value 333 454
Continuous unrealized loss position, 12 months or longer, gross unrealized losses 8 12
Continuous unrealized loss position, total, fair value 426 567
Continuous unrealized loss position, total, gross unrealized losses 8 13
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, 3 months or less 0 0
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost greater than 3 months, 6 months or less 0 0
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, greater than 6 months, 12 months or less 0 0
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, greater than 12 months 0 0
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, total 0 0
Mortgage-backed securities, collateralized mortgage obligations and pass-through securities [Member]    
Investment disclosure details    
Continuous unrealized loss position, less than 12 months, fair value 3,825 7,359
Continuous unrealized loss position, less than 12 months, gross unrealized losses 55 148
Continuous unrealized loss position, 12 months or longer, fair value 1,354 1,419
Continuous unrealized loss position, 12 months or longer, gross unrealized losses 152 188
Continuous unrealized loss position, total, fair value 5,179 8,778
Continuous unrealized loss position, total, gross unrealized losses 207 336
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, 3 months or less 3 58
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost greater than 3 months, 6 months or less 2 0
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, greater than 6 months, 12 months or less 0 0
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, greater than 12 months 0 0
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, total 5 58
Corporate and all other bonds [Member]    
Investment disclosure details    
Continuous unrealized loss position, less than 12 months, fair value 2,841 7,341
Continuous unrealized loss position, less than 12 months, gross unrealized losses 30 144
Continuous unrealized loss position, 12 months or longer, fair value 20,217 21,999
Continuous unrealized loss position, 12 months or longer, gross unrealized losses 1,248 1,786
Continuous unrealized loss position, total, fair value 23,058 29,340
Continuous unrealized loss position, total, gross unrealized losses 1,278 1,930
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, 3 months or less 4 13
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost greater than 3 months, 6 months or less 4 0
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, greater than 6 months, 12 months or less 0 0
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, greater than 12 months 1 3
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, total $ 9 $ 16