v3.26.1
accounting policy developments - Adjusted net income (Details) - CAD ($)
$ / shares in Units, $ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Reconciliation of net income (loss) with possible management-defined performance measure        
Net income (loss) $ (1,992) $ (198) $ (1,793) $ 210
Income taxes (162) 47 (107) 154
Common Shares $ (1,840) 7 $ (1,704) $ 328
Attributable to Common Shares, Per basic share $ (1.17)   $ (1.09) $ 0.22
Non-controlling interests $ 10 $ (252) $ 18 $ (272)
IFRS 18 | Proforma        
Reconciliation of net income (loss) with possible management-defined performance measure        
Net income (loss) (1,830)   (1,686)  
Common Shares $ (1,840)   $ (1,704)  
Attributable to Common Shares, Per basic share $ (1.17)   $ (1.09)  
Non-controlling interests $ 10   $ 18  
Long-term debt prepayment premium (Note 9)        
Reconciliation of net income (loss) with possible management-defined performance measure        
Net income (loss) 51   51  
Income taxes (14)   (14)  
Common Shares $ 51   $ 51  
Attributable to Common Shares, Per basic share $ 0.03   $ 0.03  
Adjusted net income | IFRS 18 | Proforma        
Reconciliation of net income (loss) with possible management-defined performance measure        
Net income (loss) $ 264   $ 628  
Common Shares $ 254   $ 610  
Attributable to Common Shares, Per basic share $ 0.16   $ 0.39  
Non-controlling interests $ 10   $ 18  
Adjusted net income | Restructuring and other costs (Note 16(a)) | IFRS 18 | Proforma        
Reconciliation of net income (loss) with possible management-defined performance measure        
Net income (loss) 189   504  
Income taxes (23)   (110)  
Common Shares $ 189   $ 504  
Attributable to Common Shares, Per basic share $ 0.12   $ 0.32  
Adjusted net income | Real estate rationalization-related restructuring impairments included in depreciation (Note 16(a)) | IFRS 18 | Proforma        
Reconciliation of net income (loss) with possible management-defined performance measure        
Net income (loss)     $ 4  
Income taxes     (1)  
Common Shares     4  
Adjusted net income | Impairment of intangible assets and goodwill (Note 18(b)) | IFRS 18 | Proforma        
Reconciliation of net income (loss) with possible management-defined performance measure        
Net income (loss) $ 2,135   2,135  
Income taxes (219)   (219)  
Common Shares $ 2,135   $ 2,135  
Attributable to Common Shares, Per basic share $ 1.36   $ 1.36  
Adjusted net income | Income-tax related adjustments | IFRS 18 | Proforma        
Reconciliation of net income (loss) with possible management-defined performance measure        
Net income (loss) $ (25)   $ (36)  
Common Shares $ (25)   $ (36)  
Attributable to Common Shares, Per basic share $ (0.01)   $ (0.02)  
Adjusted net income | Income tax on the above adjustments | IFRS 18 | Proforma        
Reconciliation of net income (loss) with possible management-defined performance measure        
Net income (loss) $ (256)   $ (344)  
Common Shares $ (256)   $ (344)  
Attributable to Common Shares, Per basic share $ (0.17)   $ (0.21)