Annual report pursuant to Section 13 and 15(d)

Information Concerning Industry Segments And Major Customers (Narrative) (Details)

v3.7.0.1
Information Concerning Industry Segments And Major Customers (Narrative) (Details)
$ in Thousands
12 Months Ended
Dec. 31, 2016
USD ($)
segment
customer
Dec. 31, 2015
USD ($)
customer
Dec. 31, 2014
customer
Segment Reporting Information [Line Items]      
Number of segments | segment 4    
Foreign Countries [Member] | Suttle [Member]      
Segment Reporting Information [Line Items]      
Long-lived assets | $ $ 2,914 $ 2,932  
United States [Member] | Sales [Member]      
Segment Reporting Information [Line Items]      
Concentration risk percentage 85.00% 81.00% 86.00%
One Customer [Member] | Sales [Member] | JDL Technologies [Member]      
Segment Reporting Information [Line Items]      
Concentration risk percentage 11.30% 10.90%  
Number of customers 1 1  
One Customer [Member] | Sales [Member] | Suttle [Member]      
Segment Reporting Information [Line Items]      
Concentration risk percentage 12.00% 16.20% 33.60%
Number of customers 1 1 1
One Customer [Member] | Accounts Receivable [Member] | Suttle [Member]      
Segment Reporting Information [Line Items]      
Concentration risk percentage 25.00% 29.00%  
Number of customers 1 1  
One Customer [Member] | Accounts Receivable [Member] | Transition Networks [Member]      
Segment Reporting Information [Line Items]      
Concentration risk percentage 17.00% 15.00%  
Number of customers 1 1