Summary of Significant Accounting Policies (Details 2) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Summary Of Significant Accounting Policies [Line Items]
Total cost	$ 6,425	$ 6,400
Accumulated depreciation and amortization	(3,716)	(3,672)
Property and equipment, net	2,709	2,728
Machinery, equipment and tooling [Member]
Summary Of Significant Accounting Policies [Line Items]
Total cost	3,293	3,293
Buildings [Member]
Summary Of Significant Accounting Policies [Line Items]
Total cost	1,711	1,686
Information Systems [Member]
Summary Of Significant Accounting Policies [Line Items]
Total cost	819	819
Land and land improvements [Member]
Summary Of Significant Accounting Policies [Line Items]
Total cost	594	594
Furniture and Fixtures [Member]
Summary Of Significant Accounting Policies [Line Items]
Total cost	$ 8	$ 8