PROPERTY AND EQUIPMENT (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 184,571	$ 174,606
Less: Accumulated depreciation	(76,756)	(72,493)
Property and equipment, net	107,815	102,113
Land [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	2,642	2,642
Building and improvements [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	55,321	53,568
Office and lab equipment [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	91,857	85,881
Furniture and fixtures [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	11,948	8,921
Construction-in-progress [Member]
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 22,803	$ 23,594