v3.26.3
Investments (Details) - Investment Information, Losses - USD ($)
$ in Millions
Sep. 30, 2026
Dec. 31, 2025
Investment disclosure details    
Continuous unrealized loss position, less than 12 months, fair value $ 58,193 $ 5,667
Continuous unrealized loss position, less than 12 months, gross unrealized losses 3,661 48
Continuous unrealized loss position, 12 months or longer, fair value 27,760 37,450
Continuous unrealized loss position, 12 months or longer, gross unrealized losses 4,417 2,801
Continuous unrealized loss position, total, fair value 85,953 43,117
Continuous unrealized loss position, total, gross unrealized losses 8,078 2,849
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, 3 months or less 1,014 19
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 7 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 302 14
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, greater than 12 months 476 550
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, total 1,799 583
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 1,835 611
Continuous unrealized loss position, less than 12 months, gross unrealized losses 154 5
Continuous unrealized loss position, 12 months or longer, fair value 1,030 1,684
Continuous unrealized loss position, 12 months or longer, gross unrealized losses 91 76
Continuous unrealized loss position, total, fair value 2,865 2,295
Continuous unrealized loss position, total, gross unrealized losses 245 81
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 18,275 2,234
Continuous unrealized loss position, less than 12 months, gross unrealized losses 1,675 28
Continuous unrealized loss position, 12 months or longer, fair value 11,615 16,428
Continuous unrealized loss position, 12 months or longer, gross unrealized losses 2,806 1,642
Continuous unrealized loss position, total, fair value 29,890 18,662
Continuous unrealized loss position, total, gross unrealized losses 4,481 1,670
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, 3 months or less 933 18
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 5 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 302 10
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, greater than 12 months 476 550
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, total 1,716 578
Debt securities issued by foreign governments [Member]    
Investment disclosure details    
Continuous unrealized loss position, less than 12 months, fair value 313 34
Continuous unrealized loss position, less than 12 months, gross unrealized losses 10 0
Continuous unrealized loss position, 12 months or longer, fair value 48 75
Continuous unrealized loss position, 12 months or longer, gross unrealized losses 2 3
Continuous unrealized loss position, total, fair value 361 109
Continuous unrealized loss position, total, gross unrealized losses 12 3
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 11,013 437
Continuous unrealized loss position, less than 12 months, gross unrealized losses 528 2
Continuous unrealized loss position, 12 months or longer, fair value 1,164 1,835
Continuous unrealized loss position, 12 months or longer, gross unrealized losses 205 128
Continuous unrealized loss position, total, fair value 12,177 2,272
Continuous unrealized loss position, total, gross unrealized losses 733 130
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, 3 months or less 74 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 74 0
Corporate and all other bonds [Member]    
Investment disclosure details    
Continuous unrealized loss position, less than 12 months, fair value 26,757 2,351
Continuous unrealized loss position, less than 12 months, gross unrealized losses 1,294 13
Continuous unrealized loss position, 12 months or longer, fair value 13,903 17,428
Continuous unrealized loss position, 12 months or longer, gross unrealized losses 1,313 952
Continuous unrealized loss position, total, fair value 40,660 19,779
Continuous unrealized loss position, total, gross unrealized losses 2,607 965
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, 3 months or less 7 1
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 4
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 $ 9 $ 5