Goodwill and Identified Intangible Assets - Changes in Carrying Amount of Goodwill (Detail) $ in Thousands	3 Months Ended
	Mar. 29, 2019 USD ($)
Goodwill [Line Items]
Balance at beginning of period	$ 240,618
Foreign currency translation adjustment	(770)
Balance at end of period	239,848
Video [Member]
Goodwill [Line Items]
Balance at beginning of period	179,839
Foreign currency translation adjustment	(786)
Balance at end of period	179,053
Cable Access [Member]
Goodwill [Line Items]
Balance at beginning of period	60,779
Foreign currency translation adjustment	16
Balance at end of period	$ 60,795