v3.25.2
OTHER COMPREHENSIVE INCOME (LOSS) - Schedule of Reclassification from Accumulated Other Comprehensive Income (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Jun. 30, 2024
Jun. 30, 2025
Jun. 30, 2024
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]        
Other net gains (losses) on investments $ 2 $ 30 $ (93) $ 37
Income tax expense (benefit) 65 100 89 198
Other underwriting expenses (146) (146) (296) (292)
NET INCOME (LOSS) (324) (387) (424) (795)
URA(D) of securities | Reclassification from Accumulated Other Comprehensive Income        
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]        
Other net gains (losses) on investments 2 11 5 16
Income tax expense (benefit) 0 (2) (1) (3)
NET INCOME (LOSS) 2 9 4 12
Benefit plan net gain (loss) | Reclassification from Accumulated Other Comprehensive Income        
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]        
Income tax expense (benefit) 2 (6) 2 (7)
Other underwriting expenses (10) 31 (10) 31
NET INCOME (LOSS) $ (8) $ 24 $ (8) $ 25