v3.25.4
Pensions and other postretirement benefits (Fair Value of Plan Assets by Asset Class) (Details) - Pensions - CAD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets $ 18,589 $ 18,435 $ 17,533
Level 3      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 1,201 1,185 1,167
Total Investment Assets      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 22,105 21,302  
Total Investment Assets | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 6,259 5,544  
Total Investment Assets | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 9,503 9,154  
Total Investment Assets | Level 3      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 1,201 1,185  
Total Investment Assets | NAV      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 5,142 5,419  
Cash and short-term investments      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 158 186  
Cash and short-term investments | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 46 61  
Cash and short-term investments | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 112 125  
Cash and short-term investments | Level 3      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Cash and short-term investments | NAV      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Canada, U.S. and supranational      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 266 76  
Canada, U.S. and supranational | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Canada, U.S. and supranational | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 266 76  
Canada, U.S. and supranational | Level 3      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Canada, U.S. and supranational | NAV      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Provinces of Canada and municipalities      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 6,384 6,337  
Provinces of Canada and municipalities | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Provinces of Canada and municipalities | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 6,384 6,337  
Provinces of Canada and municipalities | Level 3      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Provinces of Canada and municipalities | NAV      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Corporate      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 2,308 2,278  
Corporate | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Corporate | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 2,308 2,278  
Corporate | Level 3      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Corporate | NAV      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Emerging Market Debt      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 380 380  
Emerging Market Debt | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Emerging Market Debt | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 380 380  
Emerging Market Debt | Level 3      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Emerging Market Debt | NAV      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Private Debt      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 799 950  
Private Debt | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Private Debt | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Private Debt | Level 3      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Private Debt | NAV      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 799 950  
Canadian      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 287 245  
Canadian | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 287 245  
Canadian | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Canadian | Level 3      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Canadian | NAV      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
U.S.      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 3,325 2,581  
U.S. | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 3,325 2,581  
U.S. | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
U.S. | Level 3      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
U.S. | NAV      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
International      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 2,180 2,334  
International | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 2,180 2,334  
International | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
International | Level 3      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
International | NAV      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Private equities      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 766 738  
Private equities | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Private equities | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Private equities | Level 3      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Private equities | NAV      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 766 738  
Employee Benefit Plan, Real Estate      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 494 519  
Employee Benefit Plan, Real Estate | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Employee Benefit Plan, Real Estate | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Employee Benefit Plan, Real Estate | Level 3      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 213 238 252
Employee Benefit Plan, Real Estate | NAV      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 281 281  
Resource and royalties      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 1,399 1,324  
Resource and royalties | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 411 311  
Resource and royalties | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 66  
Resource and royalties | Level 3      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 988 947 $ 915
Resource and royalties | NAV      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Private Debt and Infrastructure      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 521 653  
Private Debt and Infrastructure | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Private Debt and Infrastructure | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Private Debt and Infrastructure | Level 3      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Private Debt and Infrastructure | NAV      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 521 653  
Multi-strategy      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 1,391 1,357  
Multi-strategy | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Multi-strategy | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Multi-strategy | Level 3      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Multi-strategy | NAV      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 1,391 1,357  
Fixed income      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 65 71  
Fixed income | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Fixed income | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Fixed income | Level 3      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Fixed income | NAV      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 65 71  
Equity      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 460 511  
Equity | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Equity | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Equity | Level 3      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Equity | NAV      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 460 511  
Global macro      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 859 858  
Global macro | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Global macro | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Global macro | Level 3      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Global macro | NAV      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 859 858  
Derivative assets      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 102 87  
Derivative assets | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 10 12  
Derivative assets | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 92 75  
Derivative assets | Level 3      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Derivative assets | NAV      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Derivative liabilities      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets (39) (183)  
Derivative liabilities | Level 1      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Derivative liabilities | Level 2      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets (39) (183)  
Derivative liabilities | Level 3      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Derivative liabilities | NAV      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Investment-related liabilities      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets (3,619) (2,960)  
Other      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets $ 103 $ 93