PROPERTY, PLANT, AND EQUIPMENT - Schedule of Estimated Useful Lives (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2020	Dec. 31, 2019
Property, plant and equipment
Property, plant and equipment, at cost		$ 558,861	$ 532,956
Accumulated depreciation		(93,385)	(77,631)
Property, plant and equipment, net		465,476	455,325
Land
Property, plant and equipment
Property, plant and equipment, at cost		4,466	4,466
Leasehold and building improvements
Property, plant and equipment
Property, plant and equipment, at cost		109,737	80,352
Land improvements
Property, plant and equipment
Estimated Useful Life	15 years
Property, plant and equipment, at cost		1,766	1,766
Buildings
Property, plant and equipment
Estimated Useful Life	30 years
Property, plant and equipment, at cost		165,509	112,815
Computer equipment and computer software
Property, plant and equipment
Estimated Useful Life	3 years
Property, plant and equipment, at cost		68,830	65,323
Laboratory equipment
Property, plant and equipment
Property, plant and equipment, at cost		120,362	104,008
Furniture and fixtures
Property, plant and equipment
Property, plant and equipment, at cost		20,886	14,539
Assets under construction
Property, plant and equipment
Property, plant and equipment, at cost		$ 67,305	$ 149,687
Minimum | Laboratory equipment
Property, plant and equipment
Estimated Useful Life	3 years
Minimum | Furniture and fixtures
Property, plant and equipment
Estimated Useful Life	3 years
Maximum | Laboratory equipment
Property, plant and equipment
Estimated Useful Life	10 years
Maximum | Furniture and fixtures
Property, plant and equipment
Estimated Useful Life	10 years