Furniture and Equipment - Furniture and Equipment Component (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 14,414	$ 14,932
Less accumulated depreciation and amortization	(14,108)	(14,349)
Furniture and equipment, net	306	583
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	600	596
Office Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	1,266	1,486
Laboratory Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	5,721	6,050
Leased Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	63	63
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	5,316	5,316
Software [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 1,448	$ 1,421