Annual report pursuant to Section 13 and 15(d)

Revenue Recognition (Schedule of Disaggregation of Revenues) (Details)

v3.10.0.1
Revenue Recognition (Schedule of Disaggregation of Revenues) (Details) - USD ($)
 3 Months Ended 12 Months Ended
Dec. 31, 2018
Sep. 30, 2018
Jun. 30, 2018
Mar. 31, 2018
Dec. 31, 2017
Sep. 30, 2017
Jun. 30, 2017
Mar. 31, 2017
Dec. 31, 2018
Dec. 31, 2017
Disaggregation of Revenue [Line Items]                    
Revenues $ 18,659,000 $ 15,292,000 $ 15,038,000 $ 16,774,000 $ 19,043,000 $ 20,412,000 $ 22,068,000 $ 20,800,000 $ 65,762,946 $ 82,322,618
Transition Networks [Member]                    
Disaggregation of Revenue [Line Items]                    
Revenues                 36,470,000 38,541,000
Transition Networks [Member] | North America [Member]                    
Disaggregation of Revenue [Line Items]                    
Revenues                 31,059,000 31,261,000
Transition Networks [Member] | Rest of World [Member]                    
Disaggregation of Revenue [Line Items]                    
Revenues                 2,017,000 2,314,000
Transition Networks [Member] | Europe, Middle East, Africa ("EMEA") [Member]                    
Disaggregation of Revenue [Line Items]                    
Revenues                 3,394,000 4,966,000
Transition Networks [Member] | Media Converters [Member]                    
Disaggregation of Revenue [Line Items]                    
Revenues                 20,226,000 21,670,000
Transition Networks [Member] | Ethernet Switches and Adapters [Member]                    
Disaggregation of Revenue [Line Items]                    
Revenues                 9,694,000 8,699,000
Transition Networks [Member] | Other Products [Member]                    
Disaggregation of Revenue [Line Items]                    
Revenues                 6,550,000 8,172,000
Suttle [Member]                    
Disaggregation of Revenue [Line Items]                    
Revenues                 23,410,000 32,384,000
Suttle [Member] | Communication Service Providers [Member]                    
Disaggregation of Revenue [Line Items]                    
Revenues                 19,370,000 29,071,000
Suttle [Member] | International [Member]                    
Disaggregation of Revenue [Line Items]                    
Revenues                 2,095,000 2,557,000
Suttle [Member] | Distributors [Member]                    
Disaggregation of Revenue [Line Items]                    
Revenues                 1,945,000 756,000
Suttle [Member] | Structured Cabling and Connecting System Products [Member]                    
Disaggregation of Revenue [Line Items]                    
Revenues                 21,753,000 29,932,000
Suttle [Member] | DSL and Other Products [Member]                    
Disaggregation of Revenue [Line Items]                    
Revenues                 1,657,000 2,452,000
JDL Technologies [Member]                    
Disaggregation of Revenue [Line Items]                    
Revenues                 5,134,000 11,210,000
JDL Technologies [Member] | Education [Member]                    
Disaggregation of Revenue [Line Items]                    
Revenues                 2,651,000 8,160,000
JDL Technologies [Member] | Healthcare and Commercial Clients [Member]                    
Disaggregation of Revenue [Line Items]                    
Revenues                 $ 2,483,000 $ 3,050,000