DEBT (Standby Letters of Credit) (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Line of Credit Facility [Line Items]
Risk management insurance	$ 146.7	$ 137.7
Reclamation/restoration requirements	311.3	$ 315.2	$ 283.2
Standby Letters of Credit [Member]
Line of Credit Facility [Line Items]
Risk management insurance	71.5
Reclamation/restoration requirements	7.1
Total	$ 78.6