v3.26.1
Investments (Fair Value and Losses by Investment Category and Length of Time in a Loss Position) (Details) - USD ($)
$ in Millions
Mar. 31, 2026
Dec. 31, 2025
Debt Securities [Line Items]    
Less than Twelve Months, Fair Value $ 84,519 $ 33,698
Less than Twelve Months, Unrealized Losses 1,955 976
Twelve Months or More, Fair Value 138,148 147,942
Twelve Months or More, Unrealized Losses 34,754 32,225
Fair Value 222,667 181,640
Gross Unrealized Losses 36,709 33,201
U.S. Treasury securities and obligations of U.S. government authorities and agencies    
Debt Securities [Line Items]    
Less than Twelve Months, Fair Value 7,022 3,644
Less than Twelve Months, Unrealized Losses 162 83
Twelve Months or More, Fair Value 11,075 12,075
Twelve Months or More, Unrealized Losses 4,585 4,740
Fair Value 18,097 15,719
Gross Unrealized Losses 4,747 4,823
Obligations of U.S. states and their political subdivisions    
Debt Securities [Line Items]    
Less than Twelve Months, Fair Value 669 399
Less than Twelve Months, Unrealized Losses 18 9
Twelve Months or More, Fair Value 3,310 3,631
Twelve Months or More, Unrealized Losses 566 545
Fair Value 3,979 4,030
Gross Unrealized Losses 584 554
Foreign government securities    
Debt Securities [Line Items]    
Less than Twelve Months, Fair Value 12,741 9,886
Less than Twelve Months, Unrealized Losses 489 510
Twelve Months or More, Fair Value 22,948 23,570
Twelve Months or More, Unrealized Losses 12,837 11,842
Fair Value 35,689 33,456
Gross Unrealized Losses 13,326 12,352
U.S. public corporate securities    
Debt Securities [Line Items]    
Less than Twelve Months, Fair Value 27,994 9,789
Less than Twelve Months, Unrealized Losses 672 218
Twelve Months or More, Fair Value 48,859 52,459
Twelve Months or More, Unrealized Losses 9,998 9,114
Fair Value 76,853 62,248
Gross Unrealized Losses 10,670 9,332
U.S. private corporate securities    
Debt Securities [Line Items]    
Less than Twelve Months, Fair Value 8,355 3,297
Less than Twelve Months, Unrealized Losses 157 68
Twelve Months or More, Fair Value 22,438 24,064
Twelve Months or More, Unrealized Losses 2,144 1,895
Fair Value 30,793 27,361
Gross Unrealized Losses 2,301 1,963
Foreign public corporate securities    
Debt Securities [Line Items]    
Less than Twelve Months, Fair Value 6,319 2,253
Less than Twelve Months, Unrealized Losses 132 35
Twelve Months or More, Fair Value 8,098 8,586
Twelve Months or More, Unrealized Losses 1,272 1,142
Fair Value 14,417 10,839
Gross Unrealized Losses 1,404 1,177
Foreign private corporate securities    
Debt Securities [Line Items]    
Less than Twelve Months, Fair Value 7,471 849
Less than Twelve Months, Unrealized Losses 267 44
Twelve Months or More, Fair Value 14,577 16,286
Twelve Months or More, Unrealized Losses 2,835 2,473
Fair Value 22,048 17,135
Gross Unrealized Losses 3,102 2,517
Asset-backed securities    
Debt Securities [Line Items]    
Less than Twelve Months, Fair Value 9,533 2,979
Less than Twelve Months, Unrealized Losses 30 6
Twelve Months or More, Fair Value 655 626
Twelve Months or More, Unrealized Losses 36 20
Fair Value 10,188 3,605
Gross Unrealized Losses 66 26
Commercial mortgage-backed securities    
Debt Securities [Line Items]    
Less than Twelve Months, Fair Value 1,323 249
Less than Twelve Months, Unrealized Losses 8 1
Twelve Months or More, Fair Value 5,014 5,435
Twelve Months or More, Unrealized Losses 320 301
Fair Value 6,337 5,684
Gross Unrealized Losses 328 302
Residential mortgage-backed securities    
Debt Securities [Line Items]    
Less than Twelve Months, Fair Value 3,092 353
Less than Twelve Months, Unrealized Losses 20 2
Twelve Months or More, Fair Value 1,174 1,210
Twelve Months or More, Unrealized Losses 161 153
Fair Value 4,266 1,563
Gross Unrealized Losses $ 181 $ 155