Segment, Customer Concentration and Geographical Information - Revenues Generated by Each Business Unit (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenue from External Customer [Line Items]
Total revenues	$ 10,006	$ 9,586	$ 9,386	$ 10,529	$ 10,554	$ 9,448	$ 8,528	$ 8,449	$ 39,507	$ 36,979	$ 42,675
Cost of revenues									8,152	9,317	9,707
Gross profit	$ 8,002	$ 7,627	$ 7,315	$ 8,411	$ 8,309	$ 7,247	$ 6,077	$ 6,029	31,355	27,662	32,968
Wireless [Member]
Revenue from External Customer [Line Items]
Total revenues									33,553	31,276	35,853
Graphics [Member]
Revenue from External Customer [Line Items]
Total revenues									$ 5,954	$ 5,703	$ 6,822