v3.22.4
Pensions and Other Postretirement Benefits (Fair Value of Plan Assets by Asset Class) (Details) - Pension Plan [Member] - CAD ($)
$ in Millions
Dec. 31, 2022
Dec. 31, 2021
Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets $ 16,589 $ 20,416 $ 19,723
Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 1,090 949 783
Total Investment Assets [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 17,955 22,109  
Total Investment Assets [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 5,182 8,386  
Total Investment Assets [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 6,556 8,201  
Total Investment Assets [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 1,090 949  
Total Investment Assets [Member] | NAV [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 5,127 4,573  
Cash and short-term investments [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 536 410  
Cash and short-term investments [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 72 114  
Cash and short-term investments [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 464 296  
Cash and short-term investments [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Canada, U.S. and supranational [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 466 603  
Canada, U.S. and supranational [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Canada, U.S. and supranational [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 466 603  
Canada, U.S. and supranational [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Provinces of Canada and Municipalities [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 3,861 5,343  
Provinces of Canada and Municipalities [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Provinces of Canada and Municipalities [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 3,861 5,343  
Provinces of Canada and Municipalities [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Corporate [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 1,389 1,493  
Corporate [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Corporate [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 1,389 1,493  
Corporate [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Emerging market debt [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 363 365  
Emerging market debt [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Emerging market debt [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 363 365  
Emerging market debt [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Mortgages [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 16 19  
Mortgages [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Mortgages [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 16 19  
Mortgages [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Private debt [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 997 723  
Private debt [Member] | NAV [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 997 723  
Canadian Equities [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 361 571  
Canadian Equities [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 354 571  
Canadian Equities [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 7 0  
Canadian Equities [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
U.S. Equities [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 1,931 4,388  
U.S. Equities [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 2,011 4,383  
U.S. Equities [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets (80) 5  
U.S. Equities [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
International Equities [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 2,310 2,951  
International Equities [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 2,310 2,951  
International Equities [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
International Equities [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Private Equities [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 689 625  
Private Equities [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0    
Private Equities [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets (1)    
Private Equities [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0    
Private Equities [Member] | NAV [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 690 625  
Real estate [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 404 370  
Real estate [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Real estate [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Real estate [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 249 272 279
Real estate [Member] | NAV [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 155 98  
Resource and royalties [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 1,198 978  
Resource and royalties [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 365 293  
Resource and royalties [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets (8) 8  
Resource and royalties [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 841 677 $ 504
Infrastructure [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 720 654  
Infrastructure [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Infrastructure [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 76 69  
Infrastructure [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Infrastructure [Member] | NAV [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 644 585  
Multi Strategy Funds [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 1,390 1,173  
Multi Strategy Funds [Member] | NAV [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 1,390 1,173  
Fixed Income Fund [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 8 50  
Fixed Income Fund [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0    
Fixed Income Fund [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 3    
Fixed Income Fund [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0    
Fixed Income Fund [Member] | NAV [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 5 50  
Commodity Fund [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 71 77  
Commodity Fund [Member] | NAV [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 71 77  
Equity Funds [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 247 295  
Equity Funds [Member] | NAV [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 247 295  
Global Macro Funds [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 773 708  
Global Macro Funds [Member] | NAV [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 773 708  
Downside Protection [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 70 74  
Downside Protection [Member] | Level 1 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 70 74  
Downside Protection [Member] | Level 2 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Downside Protection [Member] | Level 3 [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 0 0  
Alternative Risk Premia [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 155 239  
Alternative Risk Premia [Member] | NAV [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets 155 239  
Investment-related liabilities [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets (1,479) (1,780)  
Other [Member]      
Defined Benefit Plan Disclosure [Line Items]      
Total plan assets $ 113 $ 87