Segment Information - Summary of Revenue, Property and Equipment, Net by Geographic Region (Detail) - USD ($) $ in Thousands		3 Months Ended								12 Months Ended
		Dec. 31, 2018	Sep. 28, 2018	Jun. 29, 2018	Mar. 30, 2018	Dec. 31, 2017	Sep. 29, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016
Net revenues:
Revenue		$ 113,655	$ 100,616	$ 99,160	$ 90,127	$ 100,974	$ 92,014	$ 82,315	$ 82,943	$ 403,558	[1]	$ 358,246	[1]	$ 405,911	[1]
Property and equipment, net:
Property and equipment, net		22,321				29,265				22,321		29,265
United States
Net revenues:
Revenue	[1]									181,965		131,773		171,016
Property and equipment, net:
Property and equipment, net		10,376				13,786				10,376		13,786
Other countries
Net revenues:
Revenue	[1]									221,593		226,473		$ 234,895
Israel
Property and equipment, net:
Property and equipment, net		6,975				8,904				6,975		8,904
France
Property and equipment, net:
Property and equipment, net		3,519				4,573				3,519		4,573
All countries except United States, Israel and France [Member] [Member]
Property and equipment, net:
Property and equipment, net		$ 1,451				$ 2,002				$ 1,451		$ 2,002

[1] Revenue is attributed to countries based on the location of the customer.