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COMMITMENTS AND CONTINGENCIES - Schedule of Environmental Liability Associated with Southbridge Landfill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Accrual for Environmental Loss Contingencies [Roll Forward]
Ending balance	$ 10,787
Southbridge Landfill
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	5,936	$ 0
Accretion expense	152	82
Obligations incurred	0	6,379
Obligations settled	(915)	(525)
Ending balance	$ 5,173	$ 5,936

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 450
-SubTopic 20
-Section 50
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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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