v3.25.4
Insurance and Reinsurance Contract Assets and Liabilities - Significant Judgements and Estimates (Detail) - CAD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Future changes in financial variables amount $ 0  
Canada | CAD | Illiquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Observable years 30 years 30 years
Ultimate year 70 years 70 years
Canada | CAD | Somewhat liquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Observable years 30 years 30 years
Ultimate year 70 years 70 years
U.S. | USD | Illiquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Observable years 30 years 30 years
Ultimate year 70 years 70 years
U.S. | USD | Somewhat liquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Observable years 30 years 30 years
Ultimate year 70 years 70 years
Japan | JPY | Somewhat liquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Observable years 30 years 30 years
Ultimate year 70 years 70 years
Hong Kong | HKD | Illiquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Observable years 15 years 15 years
Ultimate year 55 years 55 years
Less than 1 year | Canada | CAD | Illiquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Years 2.89% 3.46%
Less than 1 year | Canada | CAD | Somewhat liquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Years 2.87% 3.44%
Less than 1 year | U.S. | USD | Illiquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Years 3.74% 4.48%
Less than 1 year | U.S. | USD | Somewhat liquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Years 3.85% 4.56%
Less than 1 year | Japan | JPY | Somewhat liquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Years 1.18% 0.82%
Less than 1 year | Hong Kong | HKD | Illiquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Years 2.39% 3.73%
5 years | Canada | CAD | Illiquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Years 3.85% 3.93%
5 years | Canada | CAD | Somewhat liquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Years 3.82% 3.89%
5 years | U.S. | USD | Illiquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Years 4.37% 5.05%
5 years | U.S. | USD | Somewhat liquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Years 4.42% 5.09%
5 years | Japan | JPY | Somewhat liquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Years 1.93% 1.17%
5 years | Hong Kong | HKD | Illiquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Years 3.48% 4.36%
10 years | Canada | CAD | Illiquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Years 4.94% 4.86%
10 years | Canada | CAD | Somewhat liquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Years 4.85% 4.76%
10 years | U.S. | USD | Illiquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Years 5.65% 6.01%
10 years | U.S. | USD | Somewhat liquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Years 5.55% 5.91%
10 years | Japan | JPY | Somewhat liquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Years 2.60% 1.55%
10 years | Hong Kong | HKD | Illiquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Years 4.57% 5.23%
20 years | Canada | CAD | Illiquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Years 5.36% 5.00%
20 years | Canada | CAD | Somewhat liquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Years 5.39% 4.98%
20 years | U.S. | USD | Illiquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Years 6.47% 6.33%
20 years | U.S. | USD | Somewhat liquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Years 6.47% 6.33%
20 years | Japan | JPY | Somewhat liquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Years 3.59% 2.33%
20 years | Hong Kong | HKD | Illiquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Years 4.38% 4.70%
30 years | Canada | CAD | Illiquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Years 6.10% 5.32%
30 years | Canada | CAD | Somewhat liquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Years 6.05% 5.21%
30 years | U.S. | USD | Illiquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Years 6.41% 6.15%
30 years | U.S. | USD | Somewhat liquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Years 6.40% 6.14%
30 years | Japan | JPY | Somewhat liquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Years 4.38% 2.97%
30 years | Hong Kong | HKD | Illiquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Years 4.02% 4.17%
Ultimate | Canada | CAD | Illiquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Years 4.40% 4.40%
Ultimate | Canada | CAD | Somewhat liquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Years 4.40% 4.40%
Ultimate | U.S. | USD | Illiquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Years 5.15% 5.15%
Ultimate | U.S. | USD | Somewhat liquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Years 5.03% 5.03%
Ultimate | Japan | JPY | Somewhat liquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Years 1.60% 1.60%
Ultimate | Hong Kong | HKD | Illiquid    
Disclosure of yield curve used to discount cash flows that do not vary based on returns on underlying items [line items]    
Years 3.70% 3.70%