XML 104 R76.htm IDEA: XBRL DOCUMENT v3.21.1
Other Long-Term Liabilities - Segmented Asset Retirement Obligations (Details) - CAD ($)
$ in Millions
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Disclosure of operating segments [line items]        
Asset retirement obligations $ 5,861 $ 5,771 $ 3,886 $ 4,327
North America        
Disclosure of operating segments [line items]        
Asset retirement obligations 2,899 2,792    
North Sea        
Disclosure of operating segments [line items]        
Asset retirement obligations 787 816    
Offshore Africa        
Disclosure of operating segments [line items]        
Asset retirement obligations 174 161    
Oil Sands Mining and Upgrading        
Disclosure of operating segments [line items]        
Asset retirement obligations 1,999 2,000    
Midstream and Refining        
Disclosure of operating segments [line items]        
Asset retirement obligations $ 2 $ 2