LITIGATION (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Sep. 30, 2017	Dec. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Dec. 31, 2015
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Revision in Estimates			$ 1,050,000.00
Accrual for Environmental Loss Contingencies				$ 11.5
Legal Appeal Bond						$ 6,000,000.0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax, Portion Attributable to Parent	$ (26,665,000)	$ (32,004,000)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), after Tax	(873,000)	1,308,000
Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax	(220,816,000)	(224,511,000)		(194,151,000)	$ (192,507,000)
AOCI, Derivative Qualifying as Hedge, Excluded Component, after Tax	(373,000)	0		(413,000)	0
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax	21,817,000	(24,836,000)		22,690,000	(26,144,000)
Accumulated other comprehensive loss	$ (243,006,000)	$ (249,347,000)		$ (217,254,000)	$ (218,651,000)
Judicial Ruling [Member]
Loss Contingencies [Line Items]
Loss Contingency Accrual							$ 1,620,000
Unfavorable Regulatory Action [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Revision in Estimates			$ 5,450,000