PROPERTY AND EQUIPMENT, NET (Tables)

12 Months Ended

Dec. 31, 2018

Property Plant And Equipment [Abstract]

Summarizes Components of Property and Equipment, Net

Property and equipment are recorded at historical cost, net of accumulated depreciation. The following table summarizes components of property and equipment, net for each of the periods indicated:

	As of December 31,
	2018			2017
	(in thousands)
Land	$	4,158		$	4,158
Building and improvements		22,972			14,543
Software and computer equipment		15,774			8,965
Lab equipment		17,659			9,860
Office equipment		3,663			2,211
Leasehold improvements		20,937			13,633
Construction in progress		40,010			7,808
Property and equipment, gross		125,173			61,178
Less: accumulated depreciation		(28,149	)		(18,022	)
Property and equipment, net	$	97,024		$	43,156