v3.25.4
STOCK-BASED COMPENSATION - Narrative (Details)
$ / shares in Units, $ in Millions
12 Months Ended
Dec. 31, 2025
CAD ($)
shares
$ / shares
Dec. 31, 2024
CAD ($)
shares
$ / shares
Dec. 31, 2025
USD ($)
shares
Dec. 31, 2024
USD ($)
shares
Dec. 31, 2023
shares
Disclosure of terms and conditions of share-based payment arrangement [line items]          
Liabilities from share-based payment transactions $ 189,000,000 $ 103,000,000      
Current liabilities from share-based payment transactions 114,000,000 72,000,000      
Non-current liabilities from share-based payment transactions 75,000,000 31,000,000      
Intrinsic value of liabilities from share-based payment transactions 31,000,000 32,000,000      
Expense from cash-settled share-based payment transactions $ 40,000,000 $ 70,000,000      
Weighted average exercise price of share options exercised in share-based payment arrangement (in dollars per share) | $ / shares $ 0 $ 53.04      
Unrecognized stock-based compensation expense, stock options $ 12,000,000 $ 1,000,000      
Stock-based compensation expense (recovery) $ 98,000,000 $ 54,000,000      
Performance Options          
Disclosure of terms and conditions of share-based payment arrangement [line items]          
Award vesting term (in years) 4 years        
Granted and reinvested dividends (in shares) | shares 0 0      
Other equity instruments outstanding in share-based payment arrangement (in shares) | shares 2,583,435 2,583,435 2,583,435 2,583,435  
Cash-settled stock options          
Disclosure of terms and conditions of share-based payment arrangement [line items]          
Weighted average exercise price of share options exercised in share-based payment arrangement (in dollars per share) | $ / shares $ 42.00 $ 56.88      
Stock options          
Disclosure of terms and conditions of share-based payment arrangement [line items]          
Share conversion ratio 1        
Awards authorized (in shares) | shares 65,000,000   65,000,000    
Award vesting term (in years) 4 years        
Grant exercise price determination term 5 days        
Unrecognized stock-based compensation expense, period of recognition 4 years        
Stock-based compensation expense (recovery) $ 37,000,000 $ (58,000,000)      
Stock options | Minimum          
Disclosure of terms and conditions of share-based payment arrangement [line items]          
Award term 7 years        
Stock options | Maximum          
Disclosure of terms and conditions of share-based payment arrangement [line items]          
Award term 10 years        
Restricted share units          
Disclosure of terms and conditions of share-based payment arrangement [line items]          
Share conversion ratio 1        
Award vesting term (in years) 3 years        
Granted and reinvested dividends (in shares) | shares 1,966,136 1,246,949      
Other equity instruments outstanding in share-based payment arrangement (in shares) | shares 3,329,552 2,448,224 3,329,552 2,448,224 2,551,728
Unrecognized stock-based compensation expense, period of recognition 3 years        
Shares reserved for issue (in shares) | shares 4,000,000   4,000,000    
Unrecognized stock-based compensation expense, other than options     $ 54 $ 35  
Stock-based compensation expense (recovery) $ 68,000,000 $ 20,000,000      
Performance-based RSUs          
Disclosure of terms and conditions of share-based payment arrangement [line items]          
Award vesting term (in years) 3 years        
Granted and reinvested dividends (in shares) | shares 319,896 378,296      
Performance-based RSUs | Minimum          
Disclosure of terms and conditions of share-based payment arrangement [line items]          
Performance vesting rights 0.00%        
Performance-based RSUs | Maximum          
Disclosure of terms and conditions of share-based payment arrangement [line items]          
Performance vesting rights 100.00%        
Deferred share units          
Disclosure of terms and conditions of share-based payment arrangement [line items]          
Award vesting term (in years) 3 years        
Granted and reinvested dividends (in shares) | shares 243,438 231,590      
Other equity instruments outstanding in share-based payment arrangement (in shares) | shares 983,782 908,678 983,782 908,678 956,410
Unrecognized stock-based compensation expense, period of recognition 3 years        
Unrecognized stock-based compensation expense, other than options     $ 10 $ 5  
Stock-based compensation expense (recovery) $ 15,000,000 $ (10,000,000)      
Performance-based DSUs          
Disclosure of terms and conditions of share-based payment arrangement [line items]          
Granted and reinvested dividends (in shares) | shares 5,332 6,157      
Employee Share Accumulation Plan          
Disclosure of terms and conditions of share-based payment arrangement [line items]          
Maximum employee contribution percentage 15.00%   15.00%    
Amount of maximum annual employee contribution $ 25,000        
Stock-based compensation expense (recovery) $ 57,000,000 $ 61,000,000      
Employee Share Accumulation Plan | Minimum          
Disclosure of terms and conditions of share-based payment arrangement [line items]          
Employer percentage, matching contribution 25.00%        
Employee Share Accumulation Plan | Maximum          
Disclosure of terms and conditions of share-based payment arrangement [line items]          
Employer percentage, matching contribution 50.00%        
Equity derivative instruments          
Disclosure of terms and conditions of share-based payment arrangement [line items]          
Stock-based compensation expense (recovery) $ (22,000,000) $ 102,000,000