Property, Plant, and Equipment - Components of Property, Plant, and Equipment (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Property, Plant and equipment, gross	$ 91,203	$ 84,006
Less: accumulated depreciation	(54,067)	(49,186)
Property, Plant and Equipment, Net, Total	37,136	34,820
Land [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and equipment, gross	3,951	3,951
Buildings [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and equipment, gross	18,371	18,371
Building Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and equipment, gross	15,711	13,186
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and equipment, gross	5,185	4,925
Computer Hardware and Software [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and equipment, gross	29,353	26,907
Manufacturing Test Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and equipment, gross	14,715	12,876
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and equipment, gross	$ 3,917	$ 3,790