v3.25.4
Stock-Based Compensation - Additional Information (Details)
$ / shares in Units, number in Millions, $ in Millions
12 Months Ended
Dec. 31, 2025
CAD ($)
shares
$ / shares
Dec. 31, 2024
CAD ($)
shares
$ / shares
Dec. 31, 2023
shares
Disclosure of terms and conditions of share-based payment arrangement [line items]      
Option vesting period 4 years    
Expiration period 10 years    
Number of options granted (in shares) 0 0  
Executive stock option plan      
Disclosure of terms and conditions of share-based payment arrangement [line items]      
Number of shares reserved for issue under ESOP (in shares) 73,600,000    
Stock options      
Disclosure of terms and conditions of share-based payment arrangement [line items]      
Compensation expense related to stock options | $ $ 0 $ 0  
Deferred share units plans under ESOP      
Disclosure of terms and conditions of share-based payment arrangement [line items]      
Vesting period 3 years    
Number of common shares to be received on retirement or termination (in shares) 1    
Number of deferred share units outstanding allowing holders to receive common shares (in shares) 45,000 149,000  
Deferred share units plans      
Disclosure of terms and conditions of share-based payment arrangement [line items]      
Compensation expense related to stock options | $ $ 10 $ 10  
Vesting period 36 months    
Number of common shares to be received on retirement or termination (in shares) 1,000,000    
Number of deferred share units outstanding (in shares) 45,000 149,000  
Number of deferred share units granted (in shares) 22,000 45,000  
Number of deferred share units granted under ESOP (in shares) 72,000 85,000  
Number of deferred share units outstanding allowing holders to receive payment in cash (in shares) 957,000 867,000  
Number of deferred share units outstanding allowing holders to receive payment in cash or common shares, at the option of the holder (in shares) 669,000 1,034,000  
Carrying and fair value of the DSUs liability | $ $ 83 $ 84  
Deferred share units plans | Board of director      
Disclosure of terms and conditions of share-based payment arrangement [line items]      
Number of deferred share units issued (in shares) 187,000 193,000  
Issued deferred share units price per share (in dollars per share) | $ / shares $ 49.84 $ 44.16  
Number of deferred share units outstanding allowing holders to receive common shares (in shares) 1,671,000 2,050,000 1,963,000
Deferred share units plans | Defer Receipt Of All Or Part Of Annual Bonus      
Disclosure of terms and conditions of share-based payment arrangement [line items]      
Number of deferred share units granted (in shares) 77,000 44,000  
Deferred share units plans | Defer Payment Of All Or Part Of RSUs      
Disclosure of terms and conditions of share-based payment arrangement [line items]      
Number of deferred share units granted (in shares) 16,000 19,000  
Restricted share units      
Disclosure of terms and conditions of share-based payment arrangement [line items]      
Compensation expense related to stock options | $ $ 229 $ 215  
Vesting period 36 months    
Number of deferred share units granted (in shares) 5,700,000 6,700,000  
Fair value of the RSUs and PSUs granted (in dollars per share) | $ / shares $ 49.84 $ 44.16  
Performance share units (PSUs)      
Disclosure of terms and conditions of share-based payment arrangement [line items]      
Compensation expense related to stock options | $ $ 65 $ 96  
Vesting period 36 months    
Number of deferred share units granted (in shares) 1,200,000 1,500,000  
Restricted share units and performance share units      
Disclosure of terms and conditions of share-based payment arrangement [line items]      
Carrying and fair value of the DSUs liability | $ $ 932 $ 910