Segment Information - Summary Financial Infomation by reportable segments (Details) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 28, 2019 USD ($)	Jun. 29, 2018 USD ($)	Jun. 28, 2019 USD ($) segment	Jun. 29, 2018 USD ($)
Segment Reporting Information [Line Items]
Total Net Revenue	[1]	$ 84,865	$ 99,160	$ 164,971	$ 189,287
Gross Profit		43,928	51,603	85,777	98,786
Operating Income (Loss)		(7,764)	642	$ (16,172)	(8,685)
Number of Reportable Segments | segment				2
Operating Segments [Member]
Segment Reporting Information [Line Items]
Total Net Revenue		84,865	99,160	$ 164,971	189,287
Gross Profit		45,507	53,461	89,177	103,216
Operating Income (Loss)		(2,807)	6,495	(6,661)	6,866
Operating Segments [Member] | Video [Member]
Segment Reporting Information [Line Items]
Total Net Revenue		71,625	79,208	138,801	150,956
Gross Profit		41,444	43,558	80,046	84,784
Operating Income (Loss)		4,459	6,239	6,427	8,234
Operating Segments [Member] | Cable Access [Member]
Segment Reporting Information [Line Items]
Total Net Revenue		13,240	19,952	26,170	38,331
Gross Profit		4,063	9,903	9,131	18,432
Operating Income (Loss)		$ (7,266)	$ 256	$ (13,088)	$ (1,368)

[1] Revenue is attributed to countries based on the location of the customer.