Segment, Customer Concentration and Geographical Information - Company Revenue in Different Geographic Locations (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Revenue from External Customer [Line Items]
Total revenues	$ 6,478	$ 9,586	$ 21,151	$ 29,501
Americas [Member]
Revenue from External Customer [Line Items]
Total revenues	6,218	9,514	20,662	29,079
EMEA [Member]
Revenue from External Customer [Line Items]
Total revenues	203	46	367	171
Asia Pacific [Member]
Revenue from External Customer [Line Items]
Total revenues	$ 57	$ 26	$ 122	$ 251