XML 73 R62.htm IDEA: XBRL DOCUMENT v3.10.0.1
Segmented and geographic information, and major customers (Geographic Information) (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Sep. 30, 2018
Sep. 30, 2017
Sep. 30, 2018
Sep. 30, 2017
Mexican Operations [Member]        
Disclosure of operating segments [line items]        
Derivative pricing adjustments $ 29.0 $ 5.0 $ 30.0 $ 13.0
U.S. Operations [Member]        
Disclosure of operating segments [line items]        
Derivative pricing adjustments $ 4.0 $ 2.0 $ 5.0 $ 10.0