Quarterly report pursuant to Section 13 or 15(d)

DERIVATIVE INSTRUMENTS (Estimated Losses in Future Periods) (Details)

v3.20.1
DERIVATIVE INSTRUMENTS (Estimated Losses in Future Periods) (Details) - Designated as Hedging Instrument [Member]
$ in Millions
 3 Months Ended
Mar. 31, 2020
USD ($)
Natural Gas [Member]  
Derivative Instruments, Gain (Loss) [Line Items]  
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred $ (7.0)
Energy Related Derivative [Member]  
Derivative Instruments, Gain (Loss) [Line Items]  
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred (0.2)
Electricity [Member]  
Derivative Instruments, Gain (Loss) [Line Items]  
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred (1.5)
Canada, Dollars | Foreign Exchange Contract [Member]  
Derivative Instruments, Gain (Loss) [Line Items]  
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred $ (0.2)