Property and Equipment (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment, Gross		$ 1,559	$ 1,430
Less accumulated depreciation and amortization		857	799
Total		702	631
Office and Computer Equipment [Member]
Property, Plant and Equipment, Gross		$ 244	235
Property, Plant and Equipment, Useful Life		3 years
Furniture and Fixtures [Member]
Property, Plant and Equipment, Gross		$ 23	17
Property, Plant and Equipment, Useful Life		7 years
Leasehold Improvements [Member]
Property, Plant and Equipment, Gross		$ 189	189
Property, Plant and Equipment, Useful Life	[1]	0 years
Research and Development Equipment [Member]
Property, Plant and Equipment, Gross		$ 1,103	$ 989
Property, Plant and Equipment, Useful Life		5 years

[1] Shorter of lease term or estimated useful life