v3.25.4
Employee Future Benefits - Re-measurement Gain/Loss Recorded in Other Comprehensive Income (Details) - CAD ($)
$ in Millions
12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Pension plans    
Disclosure of defined benefit plans [line items]    
Experience $ 17 $ (2)
Demographic assumption changes 24 0
Economic assumption changes (19) 101
Return on plan assets (excluding interest income) 27 (31)
Change in effect of asset limit (excluding interest) 0 (1)
Total re-measurement gains (losses) recorded in OCI, net of tax 49 67
Retiree welfare plans    
Disclosure of defined benefit plans [line items]    
Experience 10 16
Demographic assumption changes 6 0
Economic assumption changes 3 19
Return on plan assets (excluding interest income) 13 (19)
Change in effect of asset limit (excluding interest) 0 0
Total re-measurement gains (losses) recorded in OCI, net of tax $ 32 $ 16