Segment Information - Long-Lived Assets by Location (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]
Total long-lived assets	$ 26,046	$ 29,889
United States [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total long-lived assets	21,404	20,525
Israel [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total long-lived assets	4,487	9,344
Other [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Total long-lived assets	$ 155	$ 20