COMMITMENTS AND CONTINGENCIES (Details) - USD ($) $ in Thousands		12 Months Ended
	May 27, 2016	Dec. 31, 2017	Dec. 31, 2016	Mar. 31, 2016	Aug. 31, 2015
Commitments And Contingencies [Line Items]
Loss Contingency Accrual		$ 120	$ 105
Asset retirement obligation:
Asset Retirement Obligation, Current		77	78
Asset Retirement Obligations, Noncurrent		1,942	1,693
Total asset retirement obligations		$ 2,019	1,771
Management [Member]
Commitments And Contingencies [Line Items]
Length Of Agreements With Consultants, Key Management, And Others		one year
Chief Executive Officer [Member]
Commitments And Contingencies [Line Items]
Supplemental Unemployment Benefits, Severance Benefits				$ 747
Loss Contingency, Estimate of Possible Loss					$ 2,000
Increase (Decrease) in Postemployment Obligations	$ 1,800
Legal Fees	$ 700
Postemployment Benefits, Period Expense			$ 3,025