OTHER ITEMS AND CHANGES - Summary of Environmental Exit Costs by Cost (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Site Contingency [Line Items]
Southbridge Landfill closure charge (settlement), net	$ 625	$ (9,498)	$ 2,097	$ (7,740)
Southbridge Landfill
Site Contingency [Line Items]
Charlton settlement charge	0	0	0	1,216
Legal and other costs	625	502	2,097	1,044
Litigation Settlement, Amount Awarded from Other Party	0	(10,000)	0	(10,000)
Southbridge Landfill closure charge (settlement), net	$ 625	$ (9,498)	$ 2,097	$ (7,740)