Segment, Customer Concentration and Geographical Information - Company Revenue in Different Geographic Locations (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Revenue from External Customer [Line Items]
Total revenues	$ 10,544	$ 9,448	$ 8,528	$ 8,449	$ 11,843	$ 8,746	$ 10,484	$ 11,602	$ 36,979	$ 42,675	$ 43,329
Americas [Member]
Revenue from External Customer [Line Items]
Total revenues									35,689	38,532	37,724
Asia Pacific [Member]
Revenue from External Customer [Line Items]
Total revenues									326	928	2,871
EMEA [Member]
Revenue from External Customer [Line Items]
Total revenues									$ 964	$ 3,215	$ 2,734