ACCRUED AND OTHER LIABILITIES - Environmental Reserves (Details) $ in Thousands		3 Months Ended		12 Months Ended				24 Months Ended
	Jun. 30, 2016 USD ($)	Dec. 31, 2017 USD ($)	Jun. 30, 2016 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($) a	Dec. 31, 2014 USD ($) a	Dec. 31, 2015 USD ($) a
Environmental Reserve for Monitoring Environmental Remediation Work Previously Performed
Environmental reserves
Additional environmental reserve accrued		$ 51				$ 500	$ 110	$ 661
Environmental costs funded				$ 570
Environmental reserve accrued				91
Wetlands restoration
Environmental reserves
Acres | a						148.4		148.4
Estimated cost	$ 2,000		$ 2,000	2,000
Environmental costs funded				1,600
Accrued restoration cost				$ 430		$ 1,700		$ 1,700
Area of previously disposed land subject to remediation | a						148.4		148.4
Increase in accrual of remediation costs			$ 300
Minimum | Environmental Reserve for Monitoring Environmental Remediation Work Previously Performed
Environmental reserves
Estimated cost						$ 500
Minimum | Wetlands restoration
Environmental reserves
Estimated cost					$ 1,700
Maximum | Environmental Reserve for Monitoring Environmental Remediation Work Previously Performed
Environmental reserves
Acres | a							1
Estimated cost						$ 1,000
Maximum | Wetlands restoration
Environmental reserves
Estimated cost					$ 1,900