v3.26.1
OTHER COMPREHENSIVE INCOME (LOSS) - Schedule of Amount Reclassified from Accumulated Other Comprehensive Income (Details) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]    
Net gains (losses) on investments $ (10) $ (7)
Income tax expense (benefit) (83) (39)
Other underwriting expenses (216) (238)
Net income (loss) 653 210
URA(D) of securities | Reclassification From Accumulated Other Comprehensive Income    
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]    
Net gains (losses) on investments 3 5
Income tax expense (benefit) (2) (1)
Net income (loss) 1 4
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) 0 0
Other underwriting expenses 0 0
Net income (loss) $ 0 $ 0