v3.25.4
Leases - Disclosure of Right-Of-Use Assets (Details) - CAD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Reconciliation of changes in property, plant and equipment [abstract]    
Beginning balance $ 30,001 $ 30,352
Ending balance 33,541 30,001
Right-of-use assets    
Reconciliation of changes in property, plant and equipment [abstract]    
Beginning balance 4,553 4,726
Ending balance   4,553
Right-of-use assets    
Reconciliation of changes in property, plant and equipment [abstract]    
Beginning balance 4,553  
Ending balance 4,341 4,553
Cost    
Reconciliation of changes in property, plant and equipment [abstract]    
Beginning balance 88,537 86,836
Additions 4,578 4,629
Reclassified to assets held for sale (3) (11)
Ending balance 93,041 88,537
Cost | Right-of-use assets    
Reconciliation of changes in property, plant and equipment [abstract]    
Beginning balance 9,420 9,045
Additions   771
Transfers   (250)
Business acquisitions   140
Lease terminations   (190)
Impairment (losses) reversals recognized in earnings   86
Ending balance   9,420
Cost | Right-of-use assets    
Reconciliation of changes in property, plant and equipment [abstract]    
Beginning balance 9,420  
Additions 852  
Transfers (375)  
Business acquisitions 52  
Lease terminations (724)  
Impairment (losses) reversals recognized in earnings 9  
Reclassified to assets held for sale (2) (10)
Ending balance 9,232 9,420
Accumulated depreciation    
Reconciliation of changes in property, plant and equipment [abstract]    
Beginning balance (58,536) (56,484)
Ending balance (59,500) (58,536)
Accumulated depreciation | Right-of-use assets    
Reconciliation of changes in property, plant and equipment [abstract]    
Beginning balance (4,867) (4,319)
Depreciation   848
Transfers   (133)
Lease terminations   (167)
Ending balance   (4,867)
Accumulated depreciation | Right-of-use assets    
Reconciliation of changes in property, plant and equipment [abstract]    
Beginning balance (4,867)  
Depreciation 874  
Transfers (161)  
Lease terminations (689)  
Ending balance (4,891) (4,867)
Network infrastructure and equipment | Right-of-use assets    
Reconciliation of changes in property, plant and equipment [abstract]    
Beginning balance 2,024 2,168
Ending balance   2,024
Network infrastructure and equipment | Right-of-use assets    
Reconciliation of changes in property, plant and equipment [abstract]    
Beginning balance 2,024  
Ending balance 1,785 2,024
Network infrastructure and equipment | Cost | Right-of-use assets    
Reconciliation of changes in property, plant and equipment [abstract]    
Beginning balance 4,421 4,271
Additions   444
Transfers   (245)
Business acquisitions   0
Lease terminations   (49)
Impairment (losses) reversals recognized in earnings   0
Ending balance   4,421
Network infrastructure and equipment | Cost | Right-of-use assets    
Reconciliation of changes in property, plant and equipment [abstract]    
Additions 379  
Transfers (282)  
Business acquisitions 0  
Lease terminations (668)  
Impairment (losses) reversals recognized in earnings (8)  
Reclassified to assets held for sale 0 0
Ending balance 3,842  
Network infrastructure and equipment | Accumulated depreciation | Right-of-use assets    
Reconciliation of changes in property, plant and equipment [abstract]    
Beginning balance (2,397) (2,103)
Depreciation   464
Transfers   (135)
Lease terminations   (35)
Ending balance   (2,397)
Network infrastructure and equipment | Accumulated depreciation | Right-of-use assets    
Reconciliation of changes in property, plant and equipment [abstract]    
Depreciation 461  
Transfers (141)  
Lease terminations (660)  
Ending balance (2,057)  
Land and buildings | Right-of-use assets    
Reconciliation of changes in property, plant and equipment [abstract]    
Beginning balance 2,529 2,558
Ending balance   2,529
Land and buildings | Right-of-use assets    
Reconciliation of changes in property, plant and equipment [abstract]    
Beginning balance 2,529  
Ending balance 2,556 2,529
Land and buildings | Cost | Right-of-use assets    
Reconciliation of changes in property, plant and equipment [abstract]    
Beginning balance 4,999 4,774
Additions   327
Transfers   (5)
Business acquisitions   140
Lease terminations   (141)
Impairment (losses) reversals recognized in earnings   86
Ending balance   4,999
Land and buildings | Cost | Right-of-use assets    
Reconciliation of changes in property, plant and equipment [abstract]    
Additions 473  
Transfers (93)  
Business acquisitions 52  
Lease terminations (56)  
Impairment (losses) reversals recognized in earnings 17  
Reclassified to assets held for sale (2) (10)
Ending balance 5,390  
Land and buildings | Accumulated depreciation | Right-of-use assets    
Reconciliation of changes in property, plant and equipment [abstract]    
Beginning balance (2,470) (2,216)
Depreciation   384
Transfers   2
Lease terminations   (132)
Ending balance   $ (2,470)
Land and buildings | Accumulated depreciation | Right-of-use assets    
Reconciliation of changes in property, plant and equipment [abstract]    
Depreciation 413  
Transfers (20)  
Lease terminations (29)  
Ending balance $ (2,834)