Goodwill and Identified Intangible Assets - Changes in Carrying Amount of Goodwill (Detail) $ in Thousands	6 Months Ended
	Jun. 29, 2018 USD ($)
Goodwill [Line Items]
Balance at beginning of period	$ 242,827
Foreign currency translation adjustment	(1,651)
Balance at end of period	241,176
Video [Member]
Goodwill [Line Items]
Balance at beginning of period	182,012
Foreign currency translation adjustment	(1,633)
Balance at end of period	180,379
Cable Access [Member]
Goodwill [Line Items]
Balance at beginning of period	60,815
Foreign currency translation adjustment	(18)
Balance at end of period	$ 60,797