Segment Information - Segment Financial Data (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Segment Reporting Information [Line Items]
Net revenues	$ 56,119	$ 53,361	$ 120,136	$ 106,594
Income (loss) from operations	793	(5,014)	4,403	(10,453)
Total assets	161,787	158,274	161,787	158,274	$ 155,542
Depreciation and amortization	2,320	2,411	4,723	4,854
Operating Segments [Member] | BBU [Member]
Segment Reporting Information [Line Items]
Net revenues	45,399	47,885	90,277	91,574
Income (loss) from operations	6,627	5,349	12,006	7,661
Total assets	157,170	144,592	157,170	144,592
Depreciation and amortization	1,152	1,158	2,305	2,351
Operating Segments [Member] | VI Chip [Member]
Segment Reporting Information [Line Items]
Net revenues	8,736	4,634	22,916	13,975
Income (loss) from operations	(5,284)	(9,406)	(8,772)	(16,253)
Total assets	16,138	16,942	16,138	16,942
Depreciation and amortization	717	788	1,516	1,579
Operating Segments [Member] | Picor [Member]
Segment Reporting Information [Line Items]
Net revenues	3,970	2,667	11,079	5,617
Income (loss) from operations	(374)	(785)	1,643	(1,527)
Total assets	5,658	4,560	5,658	4,560
Depreciation and amortization	98	105	195	206
Operating Segments [Member] | Corporate [Member]
Segment Reporting Information [Line Items]
Income (loss) from operations	(176)	(172)	(474)	(334)
Total assets	85,119	75,182	85,119	75,182
Depreciation and amortization	353	360	707	718
Eliminations [Member]
Segment Reporting Information [Line Items]
Net revenues	(1,986)	(1,825)	(4,136)	(4,572)
Total assets	$ (102,298)	$ (83,002)	$ (102,298)	$ (83,002)