Property and Equipment (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Property, Plant and Equipment, Net, by Type [Abstract]
Property and equipment, gross	$ 13,638	$ 13,609
Accumulated depreciation and amortization	(11,930)	(11,271)
Property and equipment, net	1,708	2,338
Depreciation expense	1,238	892
Minimum
Property, Plant and Equipment, Net, by Type [Abstract]
Property and equipment, useful life	2 years
Maximum
Property, Plant and Equipment, Net, by Type [Abstract]
Property and equipment, useful life	10 years
Office furniture and equipment
Property, Plant and Equipment, Net, by Type [Abstract]
Property and equipment, gross	9,552	9,627
Office furniture and equipment | Minimum
Property, Plant and Equipment, Net, by Type [Abstract]
Property and equipment, useful life	3 years
Office furniture and equipment | Maximum
Property, Plant and Equipment, Net, by Type [Abstract]
Property and equipment, useful life	10 years
Leasehold improvements
Property, Plant and Equipment, Net, by Type [Abstract]
Property and equipment, gross	1,413	1,392
Leasehold improvements | Minimum
Property, Plant and Equipment, Net, by Type [Abstract]
Property and equipment, useful life	1 year
Leasehold improvements | Maximum
Property, Plant and Equipment, Net, by Type [Abstract]
Property and equipment, useful life	6 years
Manufacturing and test equipment
Property, Plant and Equipment, Net, by Type [Abstract]
Property and equipment, gross	$ 2,673	$ 2,590
Manufacturing and test equipment | Minimum
Property, Plant and Equipment, Net, by Type [Abstract]
Property and equipment, useful life	2 years
Manufacturing and test equipment | Maximum
Property, Plant and Equipment, Net, by Type [Abstract]
Property and equipment, useful life	10 years