XML 70 R36.htm IDEA: XBRL DOCUMENT v3.20.4
Property, plant and equipment - Summary of Right of Use Assets (Detail) - CAD ($)
$ in Millions
 9 Months Ended 12 Months Ended
Sep. 30, 2020
Dec. 31, 2019
Disclosure of detailed information about property, plant and equipment [line items]    
Beginning balance $ 26  
Ending balance 11 $ 26
Accumulated depletion, depreciation and impairment [member]    
Disclosure of detailed information about property, plant and equipment [line items]    
Beginning balance (10)  
Amortization 5 10
Additions (Terminations) (3)  
Ending balance (12) (10)
Cost [member]    
Disclosure of detailed information about property, plant and equipment [line items]    
Beginning balance 36 37
Additions (Terminations) (13) (1)
Ending balance 23 36
Office equipment | Accumulated depletion, depreciation and impairment [member]    
Disclosure of detailed information about property, plant and equipment [line items]    
Beginning balance (3)  
Amortization   3
Additions (Terminations) (3)  
Ending balance   (3)
Office equipment | Cost [member]    
Disclosure of detailed information about property, plant and equipment [line items]    
Beginning balance 13 15
Additions (Terminations) (13) (2)
Ending balance   13
Transportation [member] | Accumulated depletion, depreciation and impairment [member]    
Disclosure of detailed information about property, plant and equipment [line items]    
Beginning balance (6)  
Amortization 4 6
Ending balance (10) (6)
Transportation [member] | Cost [member]    
Disclosure of detailed information about property, plant and equipment [line items]    
Beginning balance 17 17
Additions (Terminations) (2)  
Ending balance 15 17
Vehicles | Accumulated depletion, depreciation and impairment [member]    
Disclosure of detailed information about property, plant and equipment [line items]    
Beginning balance (1)  
Amortization 1 1
Ending balance (2) (1)
Vehicles | Cost [member]    
Disclosure of detailed information about property, plant and equipment [line items]    
Beginning balance 4 3
Additions (Terminations) 2 1
Ending balance 6 4
Surface [member] | Cost [member]    
Disclosure of detailed information about property, plant and equipment [line items]    
Beginning balance 2 2
Ending balance $ 2 $ 2