Segment Reporting - Revenues by Geographic Area, Based on Billing Location of Customer and Long-Lived Assets, by Geographical Areas (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues, net	$ 99,878	$ 108,530	$ 99,354
Total long-lived assets, net	20,581	21,817
United States of America [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues, net	69,220	72,942	65,745
Total long-lived assets, net	19,861	20,825
International [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Total revenues, net	30,658	35,588	$ 33,609
Total long-lived assets, net	$ 720	$ 992