Segment Information - Long-Lived Assets by Location (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues from External Customers and Long-Lived Assets [Line Items]
Total long-lived assets	$ 29,889	$ 20,155	$ 17,017
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total long-lived assets	20,525	9,913	6,761
Israel [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total long-lived assets	9,344	10,224	10,221
Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total long-lived assets	$ 20	$ 18	$ 35