XML 204 R176.htm IDEA: XBRL DOCUMENT v3.10.0.1
Employee Future Benefits - Contributions (Details)
$ in Millions
12 Months Ended
Dec. 31, 2018
CAD ($)
Disclosure of defined benefit plans [line items]  
Expected employer contributions $ 11
Registered  
Disclosure of defined benefit plans [line items]  
Expected employer contributions 5
Supplemental  
Disclosure of defined benefit plans [line items]  
Expected employer contributions 4
Other  
Disclosure of defined benefit plans [line items]  
Expected employer contributions $ 2