Segment Information (Schedule Of Reportable Segment And Reconciliation Of Segment Contribution Income To Income Before Income Taxes) (Details) - USD ($) $ in Thousands		3 Months Ended
		Apr. 02, 2017	Apr. 03, 2016
Segment Reporting Information [Line Items]
Total net revenues		$ 323,657	$ 310,256
Total segment contribution income		50,537	53,594
Corporate and unallocated costs		(18,201)	(16,716)
Amortization of intangible assets	[1]	(4,382)	(4,165)
Stock-based compensation expense		(5,128)	(4,411)
Restructuring and other charges		(37)	(2,678)
Litigation reserves, net		0	(10)
Interest income		405	234
Other income (expense), net		335	(366)
Income before income taxes		23,529	25,482
Arlo [Member]
Segment Reporting Information [Line Items]
Total net revenues		60,712	24,265	[2]
Total segment contribution income		$ 321	$ (3,830)	[2]
Segment contribution margin (in percentage)		0.50%	(15.80%)	[2]
Connected Home [Member]
Segment Reporting Information [Line Items]
Total net revenues		$ 194,361	$ 216,110	[2]
Total segment contribution income		$ 31,712	$ 42,029	[2]
Segment contribution margin (in percentage)		16.30%	19.40%	[2]
SMB [Member]
Segment Reporting Information [Line Items]
Total net revenues		$ 68,584	$ 69,881	[2]
Total segment contribution income		$ 18,504	$ 15,395	[2]
Segment contribution margin (in percentage)		27.00%	22.00%	[2]

[1] Amount excludes amortization expense related to patents within purchased intangibles in cost of revenue.

[2] * Prior year financial information for each reportable segment has been recast to conform to the current reportable segment structure effective on January 1, 2017.