v3.19.2
financial instruments - Contract assets (Details) - CAD ($)
$ in Millions
Jun. 30, 2019
Mar. 31, 2019
Dec. 31, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2017
Credit risk            
Contract assets $ 1,441 $ 0 $ 1,475 $ 1,272 $ 1,279 $ 0
Cost/Gross amount            
Credit risk            
Contract assets 1,519   1,549      
Allowance for doubtful accounts            
Credit risk            
Contract assets (78)   (74)      
The twelve month period ending one year hence            
Credit risk            
Contract assets 1,019   1,017 907    
The twelve month period ending one year hence | Cost/Gross amount            
Credit risk            
Contract assets 1,073   1,068      
The twelve month period ending one year hence | Allowance for doubtful accounts            
Credit risk            
Contract assets (54)   (51)      
The twelve month period ending two years hence            
Credit risk            
Contract assets 407   444 354    
The twelve month period ending two years hence | Cost/Gross amount            
Credit risk            
Contract assets 430   466      
The twelve month period ending two years hence | Allowance for doubtful accounts            
Credit risk            
Contract assets (23)   (22)      
Thereafter            
Credit risk            
Contract assets 15   14 $ 11    
Thereafter | Cost/Gross amount            
Credit risk            
Contract assets 16   15      
Thereafter | Allowance for doubtful accounts            
Credit risk            
Contract assets $ (1)   $ (1)