Property and Equipment, Net (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property and equipment, net
Total property and equipment, at cost	$ 7,254	$ 6,687
Less: Accumulated depreciation	(6,349)	(6,231)
Property and equipment, net	905	456	$ 793
Depreciation expense	265	507	$ 928
Equipment
Property and equipment, net
Total property and equipment, at cost	5,055	4,723
Furniture and fixtures
Property and equipment, net
Total property and equipment, at cost	220	227
Leasehold improvements
Property and equipment, net
Total property and equipment, at cost	1,593	1,356
Software
Property and equipment, net
Total property and equipment, at cost	$ 386	$ 381