Segment, Customer Concentration and Geographical Information - Revenues Generated by Each Business Unit (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Revenue from External Customer [Line Items]
Total revenues	$ 7,459	$ 9,386	$ 14,673	$ 19,915
Wireless [Member]
Revenue from External Customer [Line Items]
Total revenues	6,303	7,887	12,276	17,106
Graphics [Member]
Revenue from External Customer [Line Items]
Total revenues	$ 1,156	$ 1,499	$ 2,397	$ 2,809