Segment Information (Schedule of Reportable Segments and Reconciliation of Segment Contribution Income to Income Before Income Taxes) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2019	Sep. 30, 2018	Sep. 29, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Total net revenue	$ 265,858	$ 269,411	$ 745,792	$ 769,888
Total segment contribution income	37,684	50,664	105,112	118,972
Corporate and unallocated costs	(16,901)	(22,391)	(51,609)	(69,727)
Amortization of intangibles	(1,520)	(1,922)	(5,212)	(5,967)
Stock-based compensation expense	(6,986)	(6,118)	(20,183)	(20,228)
Separation expense	0	(379)	(264)	(379)
Change in fair value of contingent consideration	(199)	0	(199)	0
Restructuring and other charges	77	(1)	(1,146)	(1,368)
Litigation reserves, net	(90)	0	(100)	(5)
Interest income, net	639	985	2,122	2,806
Other income (expense), net	(403)	955	425	425
Income before income taxes	12,301	21,793	28,946	24,529
Connected Home
Segment Reporting Information [Line Items]
Total net revenue	190,672	194,683	527,532	555,422
Total segment contribution income	$ 18,934	$ 30,071	$ 52,257	$ 67,222
Segment contribution margin	9.90%	15.40%	9.90%	12.10%
SMB
Segment Reporting Information [Line Items]
Total net revenue	$ 75,186	$ 74,728	$ 218,260	$ 214,466
Total segment contribution income	$ 18,750	$ 20,593	$ 52,855	$ 51,750
Segment contribution margin	24.90%	27.60%	24.20%	24.10%