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COMMITMENTS AND CONTINGENCIES - Schedule of Environmental Liability Associated with Southbridge Landfill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Accrual for Environmental Loss Contingencies [Roll Forward]
Ending balance	$ 5,747
Southbridge Landfill
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	5,173	$ 5,936
Accretion expense	124	0
Obligations incurred	0	152
Obligations settled	(701)	(915)
Ending balance	$ 4,596	$ 5,173

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Total costs accrued as of the balance sheet date for environmental loss contingencies.

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Amount of expense for newly incurred environmental loss contingencies. Includes, but is not limited to, remediation expense and interest accretion.

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Amount of cash outflow to settle environmental loss contingencies.

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