Quarterly report pursuant to Section 13 or 15(d)

DERIVATIVE INSTRUMENTS - Estimated Losses in Future Periods (Details)

v3.20.2
DERIVATIVE INSTRUMENTS - Estimated Losses in Future Periods (Details) - Designated as Hedging Instrument [Member]
$ in Millions
 6 Months Ended
Jun. 30, 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 $ (4.6)
Zinc [Member]  
Derivative Instruments, Gain (Loss) [Line Items]  
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred 0.6
Electricity [Member]  
Derivative Instruments, Gain (Loss) [Line Items]  
Derivative Instruments, Gain (Loss) Reclassification from Accumulated OCI to Income, Estimated Net Amount to be Transferred $ (1.0)