PROPERTY AND EQUIPMENT - Summary of property and equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Public Utility, Property, Plant and Equipment [Line Items]
Total	$ 11,908	$ 11,753
Less accumulated depreciation and amortization	(7,823)	(7,449)
Property and equipment, net	4,085	4,304
Land
Public Utility, Property, Plant and Equipment [Line Items]
Total	1,056	1,056
Building and improvements
Public Utility, Property, Plant and Equipment [Line Items]
Total	9,060	9,060
Computer equipment
Public Utility, Property, Plant and Equipment [Line Items]
Total	795	638
Purchased software
Public Utility, Property, Plant and Equipment [Line Items]
Total	81	83
Furniture and fixtures
Public Utility, Property, Plant and Equipment [Line Items]
Total	778	778
Office equipment
Public Utility, Property, Plant and Equipment [Line Items]
Total	$ 138	$ 138