v3.26.3
Segment Information (Details) - Amortization and Depreciation - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Segment reporting information        
Amortization and depreciation     $ 537 $ 518
Reportable Segments [Member]        
Segment reporting information        
Amortization and depreciation $ 172 $ 164 531 513
Reportable Segments [Member] | Business Insurance [Member]        
Segment reporting information        
Amortization and depreciation 103 99 318 312
Reportable Segments [Member] | Bond & Specialty Insurance [Member]        
Segment reporting information        
Amortization and depreciation 24 21 75 62
Reportable Segments [Member] | Personal Insurance [Member]        
Segment reporting information        
Amortization and depreciation $ 45 $ 44 $ 138 $ 139