v3.26.1
Investments (Details) - Investment Information, Losses - USD ($)
$ in Millions
Jun. 30, 2026
Dec. 31, 2025
Investment disclosure details    
Continuous unrealized loss position, less than 12 months, fair value $ 24,720 $ 5,667
Continuous unrealized loss position, less than 12 months, gross unrealized losses 283 48
Continuous unrealized loss position, 12 months or longer, fair value 30,584 37,450
Continuous unrealized loss position, 12 months or longer, gross unrealized losses 2,794 2,801
Continuous unrealized loss position, total, fair value 55,304 43,117
Continuous unrealized loss position, total, gross unrealized losses 3,077 2,849
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, 3 months or less 4 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 205 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 3 14
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, greater than 12 months 337 550
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, total 549 583
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 1,636 611
Continuous unrealized loss position, less than 12 months, gross unrealized losses 21 5
Continuous unrealized loss position, 12 months or longer, fair value 1,136 1,684
Continuous unrealized loss position, 12 months or longer, gross unrealized losses 79 76
Continuous unrealized loss position, total, fair value 2,772 2,295
Continuous unrealized loss position, total, gross unrealized losses 100 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 5,578 2,234
Continuous unrealized loss position, less than 12 months, gross unrealized losses 58 28
Continuous unrealized loss position, 12 months or longer, fair value 13,281 16,428
Continuous unrealized loss position, 12 months or longer, gross unrealized losses 1,580 1,642
Continuous unrealized loss position, total, fair value 18,859 18,662
Continuous unrealized loss position, total, gross unrealized losses 1,638 1,670
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, 3 months or less 2 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 205 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 3 10
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, greater than 12 months 337 550
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, total 547 578
Debt securities issued by foreign governments [Member]    
Investment disclosure details    
Continuous unrealized loss position, less than 12 months, fair value 149 34
Continuous unrealized loss position, less than 12 months, gross unrealized losses 1 0
Continuous unrealized loss position, 12 months or longer, fair value 52 75
Continuous unrealized loss position, 12 months or longer, gross unrealized losses 2 3
Continuous unrealized loss position, total, fair value 201 109
Continuous unrealized loss position, total, gross unrealized losses 3 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 3,297 437
Continuous unrealized loss position, less than 12 months, gross unrealized losses 36 2
Continuous unrealized loss position, 12 months or longer, fair value 1,273 1,835
Continuous unrealized loss position, 12 months or longer, gross unrealized losses 137 128
Continuous unrealized loss position, total, fair value 4,570 2,272
Continuous unrealized loss position, total, gross unrealized losses 173 130
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
Corporate and all other bonds [Member]    
Investment disclosure details    
Continuous unrealized loss position, less than 12 months, fair value 14,060 2,351
Continuous unrealized loss position, less than 12 months, gross unrealized losses 167 13
Continuous unrealized loss position, 12 months or longer, fair value 14,842 17,428
Continuous unrealized loss position, 12 months or longer, gross unrealized losses 996 952
Continuous unrealized loss position, total, fair value 28,902 19,779
Continuous unrealized loss position, total, gross unrealized losses 1,163 965
Unrealized investment losses on fixed maturity investments for which fair value is less than 80% of amortized cost, 3 months or less 2 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 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 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 $ 2 $ 5