v3.25.4
Insurance and Reinsurance Contract Assets and Liabilities - Potential Impact Arising from Changes to Non-Economic Assumptions (Detail) - CAD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
2% adverse change in future mortality rates for portfolios where an increase in rates increases insurance contract liabilities, gross    
Disclosure of sensitivity analysis to changes in risk variables that arise from contracts within scope of IFRS 17 [line items]    
CSM net of NCI, increase $ (700) $ (700)
Net income attributed to shareholders, increase (700) (700)
Other comprehensive income attributed to shareholders, increase 100 200
Total comprehensive income attributed to shareholders, increase (600) (500)
2% adverse change in future mortality rates for portfolios where an increase in rates increases insurance contract liabilities, net    
Disclosure of sensitivity analysis to changes in risk variables that arise from contracts within scope of IFRS 17 [line items]    
CSM net of NCI, increase (200) (200)
Net income attributed to shareholders, increase (200) (300)
Other comprehensive income attributed to shareholders, increase 0 100
Total comprehensive income attributed to shareholders, increase (200) (200)
2% adverse change in future mortality rates for portfolios where a decrease in rates increases insurance contract liabilities, gross    
Disclosure of sensitivity analysis to changes in risk variables that arise from contracts within scope of IFRS 17 [line items]    
CSM net of NCI, decrease (300) (100)
Net income attributed to shareholders, decrease 200 0
Other comprehensive income attributed to shareholders, decrease 100 100
Total comprehensive income attributed to shareholders, decrease 300 100
2% adverse change in future mortality rates for portfolios where a decrease in rates increases insurance contract liabilities, net    
Disclosure of sensitivity analysis to changes in risk variables that arise from contracts within scope of IFRS 17 [line items]    
CSM net of NCI, decrease (400) (600)
Net income attributed to shareholders, decrease (100) 0
Other comprehensive income attributed to shareholders, decrease 100 200
Total comprehensive income attributed to shareholders, decrease 0 200
5% adverse change in future morbidity rates (incidence and termination), gross    
Disclosure of sensitivity analysis to changes in risk variables that arise from contracts within scope of IFRS 17 [line items]    
CSM net of NCI, increase (2,200) (2,200)
Net income attributed to shareholders, increase (3,000) (3,000)
Other comprehensive income attributed to shareholders, increase 600 700
Total comprehensive income attributed to shareholders, increase (2,400) (2,300)
5% adverse change in future morbidity rates (incidence and termination), net    
Disclosure of sensitivity analysis to changes in risk variables that arise from contracts within scope of IFRS 17 [line items]    
CSM net of NCI, increase (1,800) (1,800)
Net income attributed to shareholders, increase (2,500) (2,700)
Other comprehensive income attributed to shareholders, increase 500 600
Total comprehensive income attributed to shareholders, increase (2,000) (2,100)
10% change in future policy termination rates for portfolios where an increase in rates increases insurance contract liabilities, gross    
Disclosure of sensitivity analysis to changes in risk variables that arise from contracts within scope of IFRS 17 [line items]    
CSM net of NCI, increase (900) (700)
Net income attributed to shareholders, increase (100) (100)
Other comprehensive income attributed to shareholders, increase (200) (200)
Total comprehensive income attributed to shareholders, increase (300) (300)
10% change in future policy termination rates for portfolios where an increase in rates increases insurance contract liabilities, net    
Disclosure of sensitivity analysis to changes in risk variables that arise from contracts within scope of IFRS 17 [line items]    
CSM net of NCI, increase (800) (600)
Net income attributed to shareholders, increase (100) (100)
Other comprehensive income attributed to shareholders, increase (200) (200)
Total comprehensive income attributed to shareholders, increase (300) (300)
10% change in future policy termination rates for portfolios where a decrease in rates increases insurance contract liabilities, gross    
Disclosure of sensitivity analysis to changes in risk variables that arise from contracts within scope of IFRS 17 [line items]    
CSM net of NCI, decrease (800) (900)
Net income attributed to shareholders, decrease (700) (700)
Other comprehensive income attributed to shareholders, decrease 500 400
Total comprehensive income attributed to shareholders, decrease (200) (300)
10% change in future policy termination rates for portfolios where a decrease in rates increases insurance contract liabilities, net    
Disclosure of sensitivity analysis to changes in risk variables that arise from contracts within scope of IFRS 17 [line items]    
CSM net of NCI, decrease (600) (700)
Net income attributed to shareholders, decrease (400) (400)
Other comprehensive income attributed to shareholders, decrease 300 300
Total comprehensive income attributed to shareholders, decrease (100) (100)
5% increase in future expense levels, gross    
Disclosure of sensitivity analysis to changes in risk variables that arise from contracts within scope of IFRS 17 [line items]    
CSM net of NCI, increase (600) (600)
Net income attributed to shareholders, increase (100) (100)
Other comprehensive income attributed to shareholders, increase 100 100
Total comprehensive income attributed to shareholders, increase 0 0
5% increase in future expense levels, net    
Disclosure of sensitivity analysis to changes in risk variables that arise from contracts within scope of IFRS 17 [line items]    
CSM net of NCI, increase (600) (600)
Net income attributed to shareholders, increase (100) (100)
Other comprehensive income attributed to shareholders, increase 100 100
Total comprehensive income attributed to shareholders, increase $ 0 $ 0
5% deterioration in incidence rates    
Disclosure of sensitivity analysis to changes in risk variables that arise from contracts within scope of IFRS 17 [line items]    
Risk variable percentage 5.00%  
5% deterioration in claim termination rates    
Disclosure of sensitivity analysis to changes in risk variables that arise from contracts within scope of IFRS 17 [line items]    
Risk variable percentage 5.00%