Accounting And Reporting Policies - Additional Information (Details)		12 Months Ended
	Jan. 01, 2018 USD ($)	Dec. 31, 2018 USD ($) Customer Segment shares	Dec. 31, 2017 USD ($) Customer shares
Accounting And Reporting Policies [Line Items]
Depreciation expense		$ 417,000	$ 567,000
Term of warranty		1 year
Accrued Warranty Expense		$ 28,000	10,000
Intangible assets carrying value		437,000	512,000
Goodwill		40,000	40,000
Research and development costs		1,947,000	1,827,000
Advertising costs		24,000	18,000
Deferred tax assets		127,000	173,000
Revenue concentration greater than 10%		$ 24,870,000	22,402,000
Number of identified reportable segments | Segment		2
Re-measurement gain (loss)		$ (74,000)	22,000
Revenues [Member] | Customer Concentration Risk [Member]
Accounting And Reporting Policies [Line Items]
Revenue concentration greater than 10%		$ 4,436,000	$ 3,744,000
Concentration risk, percentage		17.80%	16.70%
Accounts Receivable [Member] | Customer Concentration Risk [Member]
Accounting And Reporting Policies [Line Items]
Concentration risk, percentage		30.00%	32.00%
Accounts receivable		$ 1,043,000	$ 1,100,000
Number of large customers | Customer		4	4
Foreign NOLs [Member]
Accounting And Reporting Policies [Line Items]
Deferred tax assets		$ 127,000
Options [Member]
Accounting And Reporting Policies [Line Items]
Securities excluded from the diluted earnings per share computation (in shares) | shares		15,608	42,676
Warrant [Member]
Accounting And Reporting Policies [Line Items]
Securities excluded from the diluted earnings per share computation (in shares) | shares			519,241
ASU 2014-09 [Member]
Accounting And Reporting Policies [Line Items]
Cumulative effect of adoption	$ 0
Revenue, performance obligation, description of timing		The Company meets these conditions upon the Company’s satisfaction of the performance obligation, usually at the time of shipment to the customer, because control passes to the customer at that time. Our standard terms for customers are net due within 30 days, with a few exceptions, none regularly exceeding 60 days.
ASU 2016-01 [Member]
Accounting And Reporting Policies [Line Items]
Cumulative effect adjustment from adoption of Accounting Standards Update	$ 35,000
Minimum [Member] | ASU 2014-09 [Member]
Accounting And Reporting Policies [Line Items]
Customer due days		30 days
Maximum [Member]
Accounting And Reporting Policies [Line Items]
Estimated useful life of intangible assets			10 years
Maximum [Member] | ASU 2014-09 [Member]
Accounting And Reporting Policies [Line Items]
Customer due days		60 days
Buildings and Improvements [Member] | Minimum [Member]
Accounting And Reporting Policies [Line Items]
Property, Plant and Equipment, Useful Life		5 years
Buildings and Improvements [Member] | Maximum [Member]
Accounting And Reporting Policies [Line Items]
Property, Plant and Equipment, Useful Life		35 years
Other Fixed Assets [Member] | Minimum [Member]
Accounting And Reporting Policies [Line Items]
Property, Plant and Equipment, Useful Life		3 years
Other Fixed Assets [Member] | Maximum [Member]
Accounting And Reporting Policies [Line Items]
Property, Plant and Equipment, Useful Life		10 years