Property, Plant, and Equipment - Property, Plant, and Equipment (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 181,494	$ 194,115
Less: accumulated depreciation	(102,321)	(104,672)
Property, plant and equipment, net, total	79,173	89,443
Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	3,951	3,951
Building [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	24,533	24,533
Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	45,978	49,289
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	12,682	10,790
Computer Hardware And Software [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	58,162	67,474
Manufacturing Test Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	29,816	31,278
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 6,372	$ 6,800