4. PROPERTY, PLANT AND EQUIPMENT (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 20,094	$ 20,033
Less: Accumulated depreciation and amortization	(12,360)	(12,069)
Property, plant and equipment, net	7,734	7,964
Building and improvements [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 285	285
Range of Asset Lives	7 to 36 years
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 896	896
Range of Asset Lives	2 to 5 years
Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 17,896	17,887
Range of Asset Lives	2 to 30 years
Furniture, computers and office equipment [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 901	901
Range of Asset Lives	2 to 8 years
Construction in Progess [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 116	$ 64