Goodwill and Identified Intangible Assets - Changes in Carrying Amount of Goodwill (Detail) $ in Thousands	6 Months Ended
	Jun. 26, 2020 USD ($)
Goodwill [Line Items]
Balance at beginning of period	$ 239,780
Foreign currency translation adjustment, net	36
Balance at end of period	239,816
Video [Member]
Goodwill [Line Items]
Balance at beginning of period	178,982
Foreign currency translation adjustment, net	67
Balance at end of period	179,049
Cable Access [Member]
Goodwill [Line Items]
Balance at beginning of period	60,798
Foreign currency translation adjustment, net	(31)
Balance at end of period	$ 60,767