PROPERTY AND EQUIPMENT (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 92,818	$ 59,370
Less: Accumulated depreciation	(36,368)	(32,167)
Property and equipment, net	56,450	27,203
Land [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	1,006	820
Building and improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	24,101	20,384
Office and lab equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	33,269	30,728
Furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	4,431	3,097
Construction-in-progress [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 30,011	$ 4,341