Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Disaggregated revenues	$ 5,626	$ 5,576	$ 16,266	$ 17,713
Digital video headend products [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Disaggregated revenues	2,814	2,100	7,899	7,330
Data products [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Disaggregated revenues	1,112	1,782	3,566	5,168
HFC distribution products [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Disaggregated revenues	843	838	2,345	2,545
Analog video headend products [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Disaggregated revenues	411	324	1,234	1,360
Contract manufactured products [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Disaggregated revenues	227	244	606	599
Other [Member]
Revenue Recognition, Multiple-deliverable Arrangements [Line Items]
Disaggregated revenues	$ 219	$ 288	$ 616	$ 711