Property and Equipment and Intangible Assets - Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Total property and equipment, at cost	$ 17,582	$ 18,032
Less — accumulated depreciation and amortization	(14,452)	(13,982)
Total property and equipment	3,130	4,050
Machinery and equipment
Property, Plant and Equipment [Line Items]
Total property and equipment, at cost	9,026	8,557
Computer hardware and software
Property, Plant and Equipment [Line Items]
Total property and equipment, at cost	6,080	6,512
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment, at cost	2,041	2,406
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Total property and equipment, at cost	382	438
Construction in progress
Property, Plant and Equipment [Line Items]
Total property and equipment, at cost	$ 53	$ 119