Segment, Customer Concentration and Geographical Information - Revenues Generated by Each Business Unit (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
Wireless [Member]
Revenue from External Customer [Line Items]
Total revenues	5,237	8,302	17,513	25,408
Graphics [Member]
Revenue from External Customer [Line Items]
Total revenues	$ 1,241	$ 1,284	$ 3,638	$ 4,093