ACCRUED ENVIRONMENTAL REMEDIATION COSTS (Narrative) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
ACCRUED ENVIRONMENTAL REMEDIATION COSTS [Abstract]
Long-term portion of accrued environmental remediation costs	$ 12,943	$ 13,567

Carrying value of the obligation (known or estimated) arising from requirements to perform activities to remediate one or more sites, payable after twelve months or beyond the next operating cycle if longer.

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Period Type:	instant