v3.26.1
Investments - Schedule of Debt Securities in Continuous Unrealized Loss Position (Details)
$ in Millions
Mar. 31, 2026
USD ($)
security
Dec. 31, 2025
USD ($)
security
Summary of Investment Holdings [Line Items]    
Less than 12 months, gross unrealized losses $ 231 $ 74
Less than 12 months, fair value $ 13,235 $ 3,714
Less than 12 months, # of securities | security 1,480 427
12 months or longer, gross unrealized losses $ 3,848 $ 3,677
12 months or longer, fair value $ 19,604 $ 20,885
12 months or longer, # of securities | security 2,367 2,474
Total, gross unrealized losses $ 4,079 $ 3,751
Total, fair value $ 32,839 $ 24,599
Total, # of securities | security 3,695 2,848
U.S. government securities    
Summary of Investment Holdings [Line Items]    
Less than 12 months, gross unrealized losses $ 2 $ 2
Less than 12 months, fair value $ 335 $ 68
Less than 12 months, # of securities | security 23 16
12 months or longer, gross unrealized losses $ 863 $ 849
12 months or longer, fair value $ 2,238 $ 2,263
12 months or longer, # of securities | security 20 20
Total, gross unrealized losses $ 865 $ 851
Total, fair value $ 2,573 $ 2,331
Total, # of securities | security 38 31
Other government securities    
Summary of Investment Holdings [Line Items]    
Less than 12 months, gross unrealized losses $ 3 $ 1
Less than 12 months, fair value $ 116 $ 48
Less than 12 months, # of securities | security 26 7
12 months or longer, gross unrealized losses $ 199 $ 192
12 months or longer, fair value $ 856 $ 887
12 months or longer, # of securities | security 100 107
Total, gross unrealized losses $ 202 $ 193
Total, fair value $ 972 $ 935
Total, # of securities | security 124 113
Public utilities    
Summary of Investment Holdings [Line Items]    
Less than 12 months, gross unrealized losses $ 22 $ 7
Less than 12 months, fair value $ 1,083 $ 419
Less than 12 months, # of securities | security 137 44
12 months or longer, gross unrealized losses $ 508 $ 451
12 months or longer, fair value $ 3,293 $ 3,383
12 months or longer, # of securities | security 402 415
Total, gross unrealized losses $ 530 $ 458
Total, fair value $ 4,376 $ 3,802
Total, # of securities | security 522 454
Corporate securities    
Summary of Investment Holdings [Line Items]    
Less than 12 months, gross unrealized losses $ 160 $ 44
Less than 12 months, fair value $ 8,160 $ 2,300
Less than 12 months, # of securities | security 906 240
12 months or longer, gross unrealized losses $ 2,095 $ 1,998
12 months or longer, fair value $ 11,164 $ 12,130
12 months or longer, # of securities | security 1,431 1,502
Total, gross unrealized losses $ 2,255 $ 2,042
Total, fair value $ 19,324 $ 14,430
Total, # of securities | security 2,224 1,706
Residential mortgage-backed    
Summary of Investment Holdings [Line Items]    
Less than 12 months, gross unrealized losses $ 5 $ 2
Less than 12 months, fair value $ 162 $ 43
Less than 12 months, # of securities | security 63 21
12 months or longer, gross unrealized losses $ 21 $ 21
12 months or longer, fair value $ 144 $ 172
12 months or longer, # of securities | security 161 166
Total, gross unrealized losses $ 26 $ 23
Total, fair value $ 306 $ 215
Total, # of securities | security 223 187
Commercial mortgage-backed    
Summary of Investment Holdings [Line Items]    
Less than 12 months, gross unrealized losses $ 5 $ 2
Less than 12 months, fair value $ 632 $ 163
Less than 12 months, # of securities | security 85 30
12 months or longer, gross unrealized losses $ 56 $ 52
12 months or longer, fair value $ 778 $ 801
12 months or longer, # of securities | security 116 117
Total, gross unrealized losses $ 61 $ 54
Total, fair value $ 1,410 $ 964
Total, # of securities | security 194 146
Other asset-backed securities    
Summary of Investment Holdings [Line Items]    
Less than 12 months, gross unrealized losses $ 34 $ 16
Less than 12 months, fair value $ 2,747 $ 673
Less than 12 months, # of securities | security 240 69
12 months or longer, gross unrealized losses $ 106 $ 114
12 months or longer, fair value $ 1,131 $ 1,249
12 months or longer, # of securities | security 137 147
Total, gross unrealized losses $ 140 $ 130
Total, fair value $ 3,878 $ 1,922
Total, # of securities | security 370 211