v3.26.1
Equity - Schedule of Effect of the Reclassification of Significant Items out of Accumulated Other Comprehensive Income on the Respective Line Items in the Consolidated Statements of Income (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Reclassification of significant items out of Accumulated Other Comprehensive Income        
Investments $ (265) $ (258) $ (400) $ (361)
Amount Reclassified from AOCI        
Reclassification of significant items out of Accumulated Other Comprehensive Income        
Total reclassifications for the period (70) (158) (208) (428)
Unrealized Appreciation (Depreciation) of All Other Investments | Amount Reclassified from AOCI        
Reclassification of significant items out of Accumulated Other Comprehensive Income        
Investments (63) (151) (193) (413)
Total reclassifications for the period (63) (151) (193) (413)
Retirement Plan Liabilities Adjustment | Amount Reclassified from AOCI        
Reclassification of significant items out of Accumulated Other Comprehensive Income        
Total reclassifications for the period (7) (7) (15) (15)
Prior-service credit | Amount Reclassified from AOCI        
Reclassification of significant items out of Accumulated Other Comprehensive Income        
Total reclassifications for the period (1) 0 (2) (1)
Actuarial losses | Amount Reclassified from AOCI        
Reclassification of significant items out of Accumulated Other Comprehensive Income        
Total reclassifications for the period $ (6) $ (7) $ (13) $ (14)