v3.25.4
Insurance Contract Liabilities - Movements in insurance contracts issued (Details) - Property and Casualty Insurance and Reinsurance - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Jan. 01, 2025
Jan. 01, 2024
Insurance contracts liabilities        
Insurance Contract Liabilities        
Beginning Balance $ 42,909.0 $ 41,792.7    
Changes in the consolidated statement of comprehensive income:        
Insurance revenue (30,835.6) (29,589.0)    
Incurred claims and other insurance service expenses 20,472.4 19,577.6    
Amortization of acquisition costs 5,878.6 5,124.9    
Prior year reserve development and release of risk adjustment on prior year claims (1,253.1) (1,078.8)    
Insurance service expenses 25,097.9 23,623.7    
Insurance service result (5,737.7) (5,965.3)    
Net finance (income) expense from insurance contracts 2,317.6 1,634.0    
Foreign exchange effects 908.6 (806.8)    
Total changes in the consolidated statement of comprehensive income (2,511.5) (5,138.1)    
Cash flows:        
Premiums received 31,781.4 29,692.6    
Claims and other insurance service expenses paid, including investment components (18,450.2) (17,848.0)    
Insurance acquisition cash flows (5,926.5) (5,569.1)    
Changes in funds withheld (6.9) (41.1)    
Total changes from cash flows 7,397.8 6,234.4    
Investment components and other 429.7 20.0    
Ending Balance 48,225.0 42,909.0    
Liability for remaining coverage | Insurance contracts liabilities        
Insurance Contract Liabilities        
Beginning Balance 2,747.1 3,610.8    
Changes in the consolidated statement of comprehensive income:        
Insurance revenue (30,835.6) (29,589.0)    
Incurred claims and other insurance service expenses 1.0 119.5    
Amortization of acquisition costs 5,878.6 5,124.9    
Insurance service expenses 5,879.6 5,244.4    
Insurance service result (24,956.0) (24,344.6)    
Net finance (income) expense from insurance contracts 26.1 (0.6)    
Foreign exchange effects 70.6 (127.3)    
Total changes in the consolidated statement of comprehensive income (24,859.3) (24,472.5)    
Cash flows:        
Premiums received 31,781.4 29,692.6    
Insurance acquisition cash flows (5,926.5) (5,569.1)    
Changes in funds withheld 492.3 (78.3)    
Total changes from cash flows 26,347.2 24,045.2    
Investment components and other (614.3) (436.4)    
Ending Balance 3,620.7 2,747.1    
Loss component 68.3 184.6 $ 184.6 $ 64.7
Liability for incurred claims | Estimates of present value of future cash flows | Insurance contracts liabilities        
Insurance Contract Liabilities        
Beginning Balance 37,370.7 35,530.6    
Changes in the consolidated statement of comprehensive income:        
Incurred claims and other insurance service expenses 19,377.1 18,406.2    
Prior year reserve development and release of risk adjustment on prior year claims (388.8) (232.8)    
Insurance service expenses 18,988.3 18,173.4    
Insurance service result 18,988.3 18,173.4    
Net finance (income) expense from insurance contracts 2,291.5 1,634.6    
Foreign exchange effects 772.5 (625.6)    
Total changes in the consolidated statement of comprehensive income 22,052.3 19,182.4    
Cash flows:        
Claims and other insurance service expenses paid, including investment components (18,450.2) (17,848.0)    
Changes in funds withheld (499.2) 37.2    
Total changes from cash flows (18,949.4) (17,810.8)    
Investment components and other 989.1 468.5    
Ending Balance 41,462.7 37,370.7    
Liability for incurred claims | Risk adjustment for non-financial risk | Insurance contracts liabilities        
Insurance Contract Liabilities        
Beginning Balance 2,791.2 2,651.3    
Changes in the consolidated statement of comprehensive income:        
Incurred claims and other insurance service expenses 1,094.3 1,051.9    
Prior year reserve development and release of risk adjustment on prior year claims (864.3) (846.0)    
Insurance service expenses 230.0 205.9    
Insurance service result 230.0 205.9    
Foreign exchange effects 65.5 (53.9)    
Total changes in the consolidated statement of comprehensive income 295.5 152.0    
Cash flows:        
Investment components and other 54.9 (12.1)    
Ending Balance 3,141.6 2,791.2    
Gulf Insurance        
Cash flows:        
Effect of acquired contracts on net insurance results   (47.9)    
Effect of acquired contracts on net reinsurance results   54.1    
Gulf Insurance | Insurance contracts liabilities        
Changes in the consolidated statement of comprehensive income:        
Insurance revenue   3,239.0    
Insurance service expenses   2,920.6    
Cash flows:        
Effect of acquired contracts on insurance revenue   665.3    
Effect of insurance service expenses   713.2    
Global Insurers and Reinsurers | Insurance contracts liabilities        
Changes in the consolidated statement of comprehensive income:        
Foreign exchange effects 458.5 (254.0)    
Cash flows:        
Release of risk adjustment for non-financial risk as claims are paid (603.5) (630.2)    
Insurance contracts, favorable (adverse) prior year reserve development (58.4) 211.5    
North American Insurers | Insurance contracts liabilities        
Changes in the consolidated statement of comprehensive income:        
Foreign exchange effects 127.6 (220.7)    
Cash flows:        
Release of risk adjustment for non-financial risk as claims are paid (141.0) (156.5)    
Insurance contracts, favorable (adverse) prior year reserve development (5.3) (128.3)    
International Insurers and Reinsurers | Insurance contracts liabilities        
Changes in the consolidated statement of comprehensive income:        
Foreign exchange effects 186.4 (150.9)    
Cash flows:        
Release of risk adjustment for non-financial risk as claims are paid (119.8) (59.3)    
Insurance contracts, favorable (adverse) prior year reserve development $ 452.5 $ 149.6