PROPERTY AND EQUIPMENT - Details of property and equipment (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 190,226	$ 186,255
Less: Accumulated depreciation	(82,672)	(78,146)
Property and equipment, net	107,554	108,109
Buildings and Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	1,610	1,693
Machinery and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	107,275	108,945
Computer and Communication Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	28,790	29,106
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	4,246	4,119
Vehicles [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	260	262
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	37,594	33,041
Construction in Process [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 10,451	$ 9,089