ACCRUED AND OTHER LIABILITIES - Environmental Reserves (Details) $ in Thousands		3 Months Ended		12 Months Ended				60 Months Ended
	Jun. 30, 2016 USD ($)	Mar. 31, 2019 USD ($)	Jun. 30, 2016 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2015 USD ($) a	Dec. 31, 2014 USD ($) a	Dec. 31, 2018 USD ($)	Mar. 31, 2017 USD ($)
Environmental Reserve for Monitoring Environmental Remediation Work Previously Performed
Environmental reserves
Additional environmental reserve accrued					$ 51	$ 500	$ 110	$ 661
Environmental costs funded				$ 577
Environmental reserve accrued				84
Wetlands restoration
Environmental reserves
Area of land (in acres) | a						148.4
Estimated cost	$ 2,000	$ 2,400	$ 2,000	2,400
Environmental costs funded				2,300
Accrued restoration cost				$ 121		$ 1,700			$ 430
Increase in accrual of remediation costs		$ 361	$ 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
Area of land (in acres) | a							1
Estimated cost						1,000
Maximum | Wetlands restoration
Environmental reserves
Estimated cost						$ 1,900