Property, Plant and Equipment - Property, Plant and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Depreciable property and equipment at cost	$ 164,270	$ 161,153
Less: accumulated depreciation	(120,507)	(115,090)
Depreciable property, plant and equipment, net	43,763	46,063
Construction-in-progress	5,088	1,400
Property plant and equipment, net	48,851	47,463
Building and Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Depreciable property and equipment at cost	77,771	81,444
Manufacturing Equipment [Member]
Property, Plant and Equipment [Line Items]
Depreciable property and equipment at cost	21,339	20,695
Laboratory Equipment [Member]
Property, Plant and Equipment [Line Items]
Depreciable property and equipment at cost	33,806	31,214
Computers Furniture and Other [Member]
Property, Plant and Equipment [Line Items]
Depreciable property and equipment at cost	$ 31,354	$ 27,800