v3.25.4
Income Taxes - Movement of Deferred Tax Assets and Liabilities (Details) - CAD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Deferred Tax Assets And Liabilities [Roll Forward]    
Beginning balance $ 3,994 $ 5,042
Acquired in business combination 0 4
Disposals 0 0
Recognized in income 6 (311)
Deferred income tax expenses (recoveries) (183) (885)
Recognized in equity 4 5
Translation and other (98) 139
Ending balance 3,723 3,994
Loss carryforwards    
Deferred Tax Assets And Liabilities [Roll Forward]    
Beginning balance 851 670
Acquired in business combination 0 0
Disposals 0 0
Recognized in income 525 180
Deferred income tax expenses (recoveries) (1) 0
Recognized in equity (11) (13)
Translation and other (11) 14
Ending balance 1,353 851
Actuarial liabilities    
Deferred Tax Assets And Liabilities [Roll Forward]    
Beginning balance 4,164 5,813
Acquired in business combination 0 0
Disposals 0 0
Recognized in income (422) (972)
Deferred income tax expenses (recoveries) 229 (1,059)
Recognized in equity 0 (1)
Translation and other (194) 383
Ending balance 3,777 4,164
Pensions and post-employment benefits    
Deferred Tax Assets And Liabilities [Roll Forward]    
Beginning balance 153 171
Acquired in business combination 0 0
Disposals 0 0
Recognized in income 3 1
Deferred income tax expenses (recoveries) (5) (20)
Recognized in equity 0 0
Translation and other (1) 1
Ending balance 150 153
Tax credits    
Deferred Tax Assets And Liabilities [Roll Forward]    
Beginning balance 238 122
Acquired in business combination 0 0
Disposals 0 0
Recognized in income 80 109
Deferred income tax expenses (recoveries) 0 0
Recognized in equity 0 0
Translation and other (8) 7
Ending balance 310 238
Accrued interest    
Deferred Tax Assets And Liabilities [Roll Forward]    
Beginning balance 5 1
Acquired in business combination 0 0
Disposals 0 0
Recognized in income (15) 4
Deferred income tax expenses (recoveries) 0 0
Recognized in equity 0 0
Translation and other 0 0
Ending balance (10) 5
Real estate    
Deferred Tax Assets And Liabilities [Roll Forward]    
Beginning balance (970) (1,135)
Acquired in business combination 0 0
Disposals 0 0
Recognized in income (5) 214
Deferred income tax expenses (recoveries) 0 1
Recognized in equity 0 0
Translation and other 29 (50)
Ending balance (946) (970)
Lease liability    
Deferred Tax Assets And Liabilities [Roll Forward]    
Beginning balance 45 38
Acquired in business combination 0 0
Disposals 0 0
Recognized in income 0 7
Deferred income tax expenses (recoveries) 0 0
Recognized in equity 0 1
Translation and other 0 (1)
Ending balance 45 45
Right of use asset and sublease receivable    
Deferred Tax Assets And Liabilities [Roll Forward]    
Beginning balance (43) (34)
Acquired in business combination 0 0
Disposals 0 0
Recognized in income 0 (8)
Deferred income tax expenses (recoveries) 0 0
Recognized in equity 0 (1)
Translation and other 0 0
Ending balance (43) (43)
Securities and other investments    
Deferred Tax Assets And Liabilities [Roll Forward]    
Beginning balance 390 86
Acquired in business combination 0 0
Disposals 0 0
Recognized in income (150) 276
Deferred income tax expenses (recoveries) (397) 197
Recognized in equity 0 2
Translation and other 22 (171)
Ending balance (135) 390
Sale of investments    
Deferred Tax Assets And Liabilities [Roll Forward]    
Beginning balance (8) (18)
Acquired in business combination 0 0
Disposals 0 0
Recognized in income 6 10
Deferred income tax expenses (recoveries) 0 0
Recognized in equity 0 0
Translation and other 0 0
Ending balance (2) (8)
Goodwill and intangible assets    
Deferred Tax Assets And Liabilities [Roll Forward]    
Beginning balance (829) (822)
Acquired in business combination 0 0
Disposals 0 0
Recognized in income (5) 24
Deferred income tax expenses (recoveries) 0 0
Recognized in equity 0 0
Translation and other 21 (31)
Ending balance (813) (829)
Other    
Deferred Tax Assets And Liabilities [Roll Forward]    
Beginning balance (2) 150
Acquired in business combination 0 4
Disposals 0 0
Recognized in income (11) (156)
Deferred income tax expenses (recoveries) (9) (4)
Recognized in equity 15 17
Translation and other 44 (13)
Ending balance $ 37 $ (2)