Segment Information - Summary Financial Infomation by reportable segments (Details) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 25, 2020 USD ($)	Sep. 27, 2019 USD ($)	Sep. 25, 2020 USD ($) segment	Sep. 27, 2019 USD ($)
Segment Reporting Information [Line Items]
Total net revenue	[1]	$ 94,892	$ 115,725	$ 247,303	$ 280,696
Gross Profit		48,924	75,540	123,435	161,317
Operating income (loss)		(1,621)	22,549	$ (29,224)	6,377
Number of Reportable Segments | segment				2
Operating Segments [Member]
Segment Reporting Information [Line Items]
Total net revenue		94,892	115,725	$ 247,303	280,696
Gross Profit		49,507	77,571	125,980	166,748
Operating income (loss)		4,177	29,915	(10,470)	23,254
Operating Segments [Member] | Video [Member]
Segment Reporting Information [Line Items]
Total net revenue		54,641	60,055	156,466	198,856
Gross Profit		29,825	34,646	83,756	114,692
Operating income (loss)		(1,699)	(1,696)	(12,203)	4,731
Operating Segments [Member] | Cable Access [Member]
Segment Reporting Information [Line Items]
Total net revenue		40,251	55,670	90,837	81,840
Gross Profit		19,682	42,925	42,224	52,056
Operating income (loss)		$ 5,876	$ 31,611	$ 1,733	$ 18,523

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