Segment Information and Information about Geographic Areas - Net Revenues of Customer by Geographic Area (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Entity Wide Portfolio Carrying Amount, Major Customer [Line Items]
Net revenues, Total	$ 200,940	$ 157,437	$ 110,526
North America [Member]
Entity Wide Portfolio Carrying Amount, Major Customer [Line Items]
Net revenues, Total	170,667	134,988	96,416
Other [Member]
Entity Wide Portfolio Carrying Amount, Major Customer [Line Items]
Net revenues, Total	$ 30,273	$ 22,449	$ 14,110