Revenue from Contracts with Customers by Geographic Region (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Concentration Risk [Line Items]
Total revenue	$ 44,830	$ 30,590
North America
Concentration Risk [Line Items]
Total revenue	20,239
Europe
Concentration Risk [Line Items]
Total revenue	19,401
Asia and Pacific
Concentration Risk [Line Items]
Total revenue	4,947
Other
Concentration Risk [Line Items]
Total revenue	$ 243