XML 46 R84.htm IDEA: XBRL DOCUMENT v3.20.1
CAPITAL AND FINANCIAL RISK MANAGEMENT - Energy price risk (Details) - Price Risk
$ in Millions
12 Months Ended
Dec. 31, 2019
USD ($)
Capital and financial risk management  
Percentage of increase in price 10.00%
Percentage of decrease in price 10.00%
Increase in price Effect on OCI before taxes, gain (loss) $ 9.0
Decrease in price Effect on OCI before taxes, gain (loss) $ (8.9)