Segment Information - Company's Revenue by Geographic Region, Based on Customer's Location (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 84,244	$ 72,308
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	36,404	37,645
EMEA [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	17,124	13,780
APAC [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	21,238	13,706
Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	9,478	7,177
Americas [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 45,882	$ 44,822