Schedule Of Reportable Segment And Reconciliation Of Segment Contribution Income To Income Before Income Taxes (Details) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2017	Oct. 01, 2017	Jul. 02, 2017	Apr. 02, 2017	Dec. 31, 2016	Oct. 02, 2016	Jul. 03, 2016	Apr. 03, 2016	Dec. 31, 2017	Dec. 31, 2016		Dec. 31, 2015
Segment Reporting Information [Line Items]
Total net revenue		$ 397,057	$ 355,483	$ 330,723	$ 323,657	$ 367,929	$ 338,458	$ 311,655	$ 310,256	$ 1,406,920	$ 1,328,298		$ 1,300,695
Total segment contribution income										196,976	222,803		177,775
Corporate and unallocated costs										(75,382)	(69,140)		(54,501)
Amortization of intangible assets	[1]									(12,597)	(16,733)		(16,969)
Stock-based compensation expense										(22,147)	(18,949)		(16,825)
Restructuring and other charges										(97)	(3,881)		(6,398)
Losses on inventory commitments due to restructuring										0	0		(407)
Litigation reserves, net										(176)	(73)		2,682
Interest income										2,113	1,163		295
Other income (expense), net										2,024	(121)		(88)
Income before income taxes										90,714	115,069		85,564
Arlo [Member]
Segment Reporting Information [Line Items]
Total net revenue										378,413	188,469	[2]	91,636	[2]
Total segment contribution income										$ 29,591	$ (5,218)	[2]	$ (126)	[2]
Segment contribution margin (in percentage)										7.80%	(2.80%)	[2]	(0.10%)	[2]
Connected Home [Member]
Segment Reporting Information [Line Items]
Total net revenue										$ 762,069	$ 844,818	[2]	$ 937,215	[2]
Total segment contribution income										$ 101,993	$ 152,560	[2]	$ 121,745	[2]
Segment contribution margin (in percentage)										13.40%	18.10%	[2]	13.00%	[2]
SMB [Member]
Segment Reporting Information [Line Items]
Total net revenue										$ 266,438	$ 295,011	[2]	$ 271,844	[2]
Total segment contribution income										$ 65,392	$ 75,461	[2]	$ 56,156	[2]
Segment contribution margin (in percentage)										24.50%	25.60%	[2]	20.70%	[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.