Segment Information - Company's Revenue by Geographic Region, Based on Customer's Location (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net revenue	$ 321,716	$ 264,455	$ 234,298
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net revenue	146,215	143,607	141,225
EMEA [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net revenue	63,884	50,838	47,429
APAC [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net revenue	63,959	48,391	30,180
Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total net revenue	$ 47,658	$ 21,619	$ 15,464