Segment Information Segment Income or Loss Reconciliation (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended
	Sep. 28, 2018		Sep. 29, 2017	Sep. 28, 2018	Sep. 29, 2017
Segment Reporting Information [Line Items]
Operating Income (Loss)	$ (3,651)		$ (14,206)	$ (12,336)	$ (62,786)
Amortization of warrants	(790)			(1,185)
Unallocated Corporate Expenses	(53,753)		(61,231)	(161,224)	(184,034)
Stock-based compensation	(5,433)		(3,720)	(14,202)	(11,107)
Amortization of intangibles	(2,087)		(2,088)	(6,281)	(6,232)
Nonoperating Income (Expense)	(3,237)		(3,292)	(9,190)	(9,892)
Loss before income taxes	(6,888)		(17,498)	(21,526)	(72,678)
Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating Income (Loss)	5,653	[1]	1,652	12,914	(26,622)
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Unallocated Corporate Expenses	$ (994)		$ (10,050)	$ (3,582)	$ (18,825)

[1] The Company has historically employed an aggregate allocation methodology based on total revenues to attribute professional services revenue and sales expenses between its Video and Cable Access segments. Beginning in the fourth quarter of 2017, the Company prospectively changed to a more precise attribution methodology as the activities of selling and supporting the CableOS solution have become increasingly distinct from those of Video solutions. The impact of making this change in the three and nine months ended September 29, 2017 compared to the Company’s historical approach was a decrease in operating income of $2.7 million and an increase in operating loss of $5.9 million, respectively, from the Video segment and a corresponding decrease in operating loss of the Cable Access segment. The Company believes that the updated allocation methodology will provide greater clarity regarding the operating metrics of the Video and Cable Access business segments.