v3.26.1
Other Comprehensive Income (Loss) and Accumulated Other Comprehensive Income (Loss) (Details) - Reclassifications - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Mar. 31, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Reclassification Adjustment out of Accumulated Other Comprehensive Income (Loss)          
Reclassification adjustment impacting net realized investment gains (losses) on the consolidated statement of income $ (60)   $ (6) $ (109) $ 55
Reclassification adjustment impacting claims and claim adjustment expenses (benefit) on the consolidated statement of income 5,922   6,789 12,304 14,795
Reclassification adjustment impacting general and administrative expenses (benefit) on the consolidated statement of income 1,565   1,545 3,106 3,004
Total reclassifications (2,767)   (1,881) (4,886) (2,349)
Income tax (expense) benefit (559)   (372) (967) (445)
Amounts reclassified from accumulated other comprehensive income (loss), net of taxes (2,208)   (1,509) (3,919) (1,904)
Accumulated Other Comprehensive Income (Loss) [Member] | Reclassification out of Accumulated Other Comprehensive Income (Loss) [Member]          
Reclassification Adjustment out of Accumulated Other Comprehensive Income (Loss)          
Total reclassifications 29   17 386 48
Income tax (expense) benefit 5   4 10 10
Amounts reclassified from accumulated other comprehensive income (loss), net of taxes 24   13 376 38
Changes in Net Unrealized Gains (Losses) on Investment Securities Having No Credit Losses Recognized in the Consolidated Statement of Income [Member] | Reclassification out of Accumulated Other Comprehensive Income (Loss) [Member]          
Reclassification Adjustment out of Accumulated Other Comprehensive Income (Loss)          
Reclassification adjustment impacting net realized investment gains (losses) on the consolidated statement of income 31   17 38 48
Income tax (expense) benefit 6   4 11 10
Amounts reclassified from accumulated other comprehensive income (loss), net of taxes 25   13 27 38
Changes in Net Unrealized Gains (Losses) on Investment Securities Having No Credit Losses Recognized in the Consolidated Statement of Income [Member] | Reclassification out of Accumulated Other Comprehensive Income (Loss) [Member] | Canadian insurance business excluding surety business [Member] | Disposal group, disposed of by sale, not discontinued operations [Member]          
Reclassification Adjustment out of Accumulated Other Comprehensive Income (Loss)          
Reclassification adjustment impacting net realized investment gains (losses) on the consolidated statement of income   $ (16)      
Changes in Net Unrealized Gains (Losses) on Investment Securities Having Credit Losses Recognized in the Consolidated Statement of Income [Member] | Reclassification out of Accumulated Other Comprehensive Income (Loss) [Member]          
Reclassification Adjustment out of Accumulated Other Comprehensive Income (Loss)          
Reclassification adjustment impacting net realized investment gains (losses) on the consolidated statement of income 0   0 0 0
Income tax (expense) benefit 0   0 0 0
Amounts reclassified from accumulated other comprehensive income (loss), net of taxes 0   0 0 0
Net Benefit Plan Assets and Obligations Recognized in Shareholders' Equity [Member] | Reclassification out of Accumulated Other Comprehensive Income (Loss) [Member]          
Reclassification Adjustment out of Accumulated Other Comprehensive Income (Loss)          
Reclassification adjustment impacting net realized investment gains (losses) on the consolidated statement of income 0   0 (4) 0
Reclassification adjustment impacting claims and claim adjustment expenses (benefit) on the consolidated statement of income (1)   0 (2) 0
Reclassification adjustment impacting general and administrative expenses (benefit) on the consolidated statement of income (1)   0 (2) 0
Total reclassifications (2)   0 (8) 0
Income tax (expense) benefit (1)   0 (1) 0
Amounts reclassified from accumulated other comprehensive income (loss), net of taxes (1)   0 (7) 0
Net Benefit Plan Assets and Obligations Recognized in Shareholders' Equity [Member] | Reclassification out of Accumulated Other Comprehensive Income (Loss) [Member] | Canadian insurance business excluding surety business [Member] | Disposal group, disposed of by sale, not discontinued operations [Member]          
Reclassification Adjustment out of Accumulated Other Comprehensive Income (Loss)          
Reclassification adjustment impacting net realized investment gains (losses) on the consolidated statement of income   (4)      
Net Unrealized Foreign Currency Translation [Member] | Reclassification out of Accumulated Other Comprehensive Income (Loss) [Member]          
Reclassification Adjustment out of Accumulated Other Comprehensive Income (Loss)          
Reclassification adjustment impacting net realized investment gains (losses) on the consolidated statement of income 0   0 356 0
Income tax (expense) benefit 0   0 0 0
Amounts reclassified from accumulated other comprehensive income (loss), net of taxes $ 0   $ 0 $ 356 $ 0
Net Unrealized Foreign Currency Translation [Member] | Reclassification out of Accumulated Other Comprehensive Income (Loss) [Member] | Canadian insurance business excluding surety business [Member] | Disposal group, disposed of by sale, not discontinued operations [Member]          
Reclassification Adjustment out of Accumulated Other Comprehensive Income (Loss)          
Reclassification adjustment impacting net realized investment gains (losses) on the consolidated statement of income   $ 356