Equipment and Leasehold Improvements - Components of Equipment and Leasehold Improvements (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Property, Plant, and Equipment, Gross	$ 19,393	$ 19,172
Less: Accumulated depreciation and amortization	(16,929)	(16,144)
Property, Plant, and Equipment, Net, Total	2,464	3,028
Machinery and equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant, and Equipment, Gross	13,737	13,559
Office equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant, and Equipment, Gross	752	731
Office furniture [Member]
Property, Plant and Equipment [Line Items]
Property, Plant, and Equipment, Gross	110	108
Leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant, and Equipment, Gross	4,749	4,749
Construction in progress [Member]
Property, Plant and Equipment [Line Items]
Property, Plant, and Equipment, Gross	$ 45	$ 25