REMEDIAL LIABILITIES - Changes in Remedial Liabilities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Changes to remedial liabilities
Balance at the beginning of the period	$ 114,813	$ 114,173
Accretion	4,388	4,398
Changes in estimates recorded to consolidated statement of operations	296	4,130
Expenditures	(8,904)	(8,203)
Currency translation and other	64	315
Liabilities assumed in acquisitions	1,216
Balance at the end of the period	111,873	114,813
Remedial Liabilities for Landfill Sites
Changes to remedial liabilities
Balance at the beginning of the period	1,865	1,851
Accretion	90	90
Changes in estimates recorded to consolidated statement of operations	(126)	(15)
Expenditures	(49)	(61)
Currency translation and other	0	0
Liabilities assumed in acquisitions	0
Balance at the end of the period	1,780	1,865
Remedial Liabilities for Inactive Sites
Changes to remedial liabilities
Balance at the beginning of the period	63,060	61,991
Accretion	2,614	2,607
Changes in estimates recorded to consolidated statement of operations	(178)	2,873
Expenditures	(4,889)	(4,332)
Currency translation and other	(820)	(79)
Liabilities assumed in acquisitions	0
Balance at the end of the period	59,787	63,060
Remedial Liabilities (Including Superfund) for Non-Landfill Operations
Changes to remedial liabilities
Balance at the beginning of the period	49,888	50,331
Accretion	1,684	1,701
Changes in estimates recorded to consolidated statement of operations	600	1,272
Expenditures	(3,966)	(3,810)
Currency translation and other	884	394
Liabilities assumed in acquisitions	1,216
Balance at the end of the period	$ 50,306	$ 49,888