REMEDIAL LIABILITIES (Changes in Remedial Liabilities) (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021 USD ($)
Accrual for Environmental Loss Contingencies [Roll Forward]
Balance at January 1, 2021	$ 114,813
Accretion	1,090
Changes in estimates recorded to consolidated statement of operations	246
Expenditures	(2,082)
Currency translation and other	181
Balance at March 31, 2021	114,248
Remedial Liabilities for Landfill Sites
Accrual for Environmental Loss Contingencies [Roll Forward]
Balance at January 1, 2021	1,865
Accretion	22
Changes in estimates recorded to consolidated statement of operations	17
Expenditures	(12)
Currency translation and other	0
Balance at March 31, 2021	1,892
Remedial Liabilities for Inactive Sites
Accrual for Environmental Loss Contingencies [Roll Forward]
Balance at January 1, 2021	63,060
Accretion	654
Changes in estimates recorded to consolidated statement of operations	180
Expenditures	(950)
Currency translation and other	(812)
Balance at March 31, 2021	62,132
Remedial Liabilities (Including Superfund) for Non-Landfill Operations
Accrual for Environmental Loss Contingencies [Roll Forward]
Balance at January 1, 2021	49,888
Accretion	414
Changes in estimates recorded to consolidated statement of operations	49
Expenditures	(1,120)
Currency translation and other	993
Balance at March 31, 2021	$ 50,224