v3.25.4
Financial and capital management - Financial Instruments Measured at Fair Value (Details) - CAD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Disclosure of financial assets [line items]    
Assets $ 80,165 $ 73,485
Publicly-traded and privately-held investments    
Disclosure of financial assets [line items]    
Assets 1,198 877
Publicly-traded and privately-held investments | Quoted prices in active markets for identical assets (level 1)    
Disclosure of financial assets [line items]    
Assets 105 35
Publicly-traded and privately-held investments | Observable market data (level 2)    
Disclosure of financial assets [line items]    
Assets 0 0
Publicly-traded and privately-held investments | Non-observable market inputs (level 3)    
Disclosure of financial assets [line items]    
Assets 1,093 842
Derivative financial instruments | Derivative financial instruments    
Disclosure of financial assets [line items]    
Assets (liabilities) (513) (368)
Derivative financial instruments | Derivative financial instruments | Quoted prices in active markets for identical assets (level 1)    
Disclosure of financial assets [line items]    
Assets (liabilities) 0 0
Derivative financial instruments | Derivative financial instruments | Observable market data (level 2)    
Disclosure of financial assets [line items]    
Assets (liabilities) (513) (368)
Derivative financial instruments | Derivative financial instruments | Non-observable market inputs (level 3)    
Disclosure of financial assets [line items]    
Assets (liabilities) 0 0
Investments    
Disclosure of financial assets [line items]    
Assets 246 225
Investments | Quoted prices in active markets for identical assets (level 1)    
Disclosure of financial assets [line items]    
Assets 0 0
Investments | Observable market data (level 2)    
Disclosure of financial assets [line items]    
Assets 246 225
Investments | Non-observable market inputs (level 3)    
Disclosure of financial assets [line items]    
Assets $ 0 $ 0