Revenue (Schedule of Net Revenue Disaggregated by Geographical Region and Sales Channel) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Apr. 01, 2018
Disaggregation of Revenue [Line Items]
Total net revenue	$ 249,082	$ 245,201
Service provider
Disaggregation of Revenue [Line Items]
Total net revenue	38,294	42,860
Non-service provider
Disaggregation of Revenue [Line Items]
Total net revenue	210,788	202,341
Americas
Disaggregation of Revenue [Line Items]
Total net revenue	148,029	160,012
EMEA
Disaggregation of Revenue [Line Items]
Total net revenue	56,963	47,434
APAC
Disaggregation of Revenue [Line Items]
Total net revenue	44,090	37,755
Connected Home
Disaggregation of Revenue [Line Items]
Total net revenue	169,365	174,315
Connected Home | Service provider
Disaggregation of Revenue [Line Items]
Total net revenue	36,818	41,797
Connected Home | Non-service provider
Disaggregation of Revenue [Line Items]
Total net revenue	132,547	132,518
Connected Home | Americas
Disaggregation of Revenue [Line Items]
Total net revenue	113,687	129,038
Connected Home | EMEA
Disaggregation of Revenue [Line Items]
Total net revenue	25,690	21,010
Connected Home | APAC
Disaggregation of Revenue [Line Items]
Total net revenue	29,988	24,267
SMB
Disaggregation of Revenue [Line Items]
Total net revenue	79,717	70,886
SMB | Service provider
Disaggregation of Revenue [Line Items]
Total net revenue	1,476	1,063
SMB | Non-service provider
Disaggregation of Revenue [Line Items]
Total net revenue	78,241	69,823
SMB | Americas
Disaggregation of Revenue [Line Items]
Total net revenue	34,342	30,974
SMB | EMEA
Disaggregation of Revenue [Line Items]
Total net revenue	31,273	26,424
SMB | APAC
Disaggregation of Revenue [Line Items]
Total net revenue	$ 14,102	$ 13,488