Revenue (Schedule of Net Revenue Disaggregated by Geographical Region and Sales Channel) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jul. 01, 2018	Jun. 30, 2019	Jul. 01, 2018
Disaggregation of Revenue [Line Items]
Total net revenue	$ 230,852	$ 255,276	$ 479,934	$ 500,477
Service provider
Disaggregation of Revenue [Line Items]
Total net revenue	27,823	47,033	66,117	89,893
Non-service provider
Disaggregation of Revenue [Line Items]
Total net revenue	203,029	208,243	413,817	410,584
Americas
Disaggregation of Revenue [Line Items]
Total net revenue	157,170	174,414	305,199	334,426
EMEA
Disaggregation of Revenue [Line Items]
Total net revenue	43,091	48,209	100,054	95,643
APAC
Disaggregation of Revenue [Line Items]
Total net revenue	30,591	32,653	74,681	70,408
Connected Home
Disaggregation of Revenue [Line Items]
Total net revenue	167,495	186,424	336,860	360,739
Connected Home | Service provider
Disaggregation of Revenue [Line Items]
Total net revenue	26,901	46,333	63,719	88,130
Connected Home | Non-service provider
Disaggregation of Revenue [Line Items]
Total net revenue	140,594	140,091	273,141	272,609
Connected Home | Americas
Disaggregation of Revenue [Line Items]
Total net revenue	131,669	145,570	245,356	274,608
Connected Home | EMEA
Disaggregation of Revenue [Line Items]
Total net revenue	17,526	20,505	43,216	41,515
Connected Home | APAC
Disaggregation of Revenue [Line Items]
Total net revenue	18,300	20,349	48,288	44,616
SMB
Disaggregation of Revenue [Line Items]
Total net revenue	63,357	68,852	143,074	139,738
SMB | Service provider
Disaggregation of Revenue [Line Items]
Total net revenue	922	700	2,398	1,763
SMB | Non-service provider
Disaggregation of Revenue [Line Items]
Total net revenue	62,435	68,152	140,676	137,975
SMB | Americas
Disaggregation of Revenue [Line Items]
Total net revenue	25,501	28,844	59,843	59,818
SMB | EMEA
Disaggregation of Revenue [Line Items]
Total net revenue	25,565	27,704	56,838	54,128
SMB | APAC
Disaggregation of Revenue [Line Items]
Total net revenue	$ 12,291	$ 12,304	$ 26,393	$ 25,792