Property, Plant, and Equipment (Summary of Property, Plant, and Equipment) (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Capitalized manufacturing equipment for specific use	$ 259,677	$ 254,419
Less accumulated depreciation and amortization	(114,993)	(112,258)
Total property, plant, and equipment, net	144,684	142,161
Buildings
Property, Plant and Equipment [Line Items]
Capitalized manufacturing equipment for specific use	82,580	82,309
Leasehold improvement
Property, Plant and Equipment [Line Items]
Capitalized manufacturing equipment for specific use	23,392	23,392
Land
Property, Plant and Equipment [Line Items]
Capitalized manufacturing equipment for specific use	6,940	6,895
Machinery and equipment
Property, Plant and Equipment [Line Items]
Capitalized manufacturing equipment for specific use	109,689	108,442
Furniture, fixtures, and automobiles
Property, Plant and Equipment [Line Items]
Capitalized manufacturing equipment for specific use	14,209	13,439
Construction in progress
Property, Plant and Equipment [Line Items]
Capitalized manufacturing equipment for specific use	$ 22,867	$ 19,942