v3.22.4
Debt (US Dollar-denominated Debt) (Details) - US Dollar-Denominated [Member]
$ in Millions, $ in Millions
Dec. 31, 2022
USD ($)
Dec. 31, 2022
CAD ($)
Dec. 31, 2021
USD ($)
Dec. 31, 2021
CAD ($)
Debt Instrument [Line Items]        
Debt outstanding $ 8,975 $ 12,165 $ 7,275 $ 9,193
Notes and debentures [Member]        
Debt Instrument [Line Items]        
Debt outstanding 7,800   6,550  
Commercial paper [Member]        
Debt Instrument [Line Items]        
Debt outstanding 594   111  
Finance lease liability [Member]        
Debt Instrument [Line Items]        
Debt outstanding 7   8  
Equipment Loans And Other [Member]        
Debt Instrument [Line Items]        
Debt outstanding $ 574   $ 606