Segment Information - Significant Segment Financial Data (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Segment Reporting Information [Line Items]
Net revenues	$ 53,361	$ 46,865	$ 106,594	$ 88,811
Income (loss) from operations	(5,014)	(6,982)	(10,453)	(15,478)
Total assets	158,274	177,268	158,274	177,268	165,640
Depreciation and amortization	2,411	2,534	4,854	5,028
Operating Segments [Member] | BBU [Member]
Segment Reporting Information [Line Items]
Net revenues	47,885	40,211	91,574	78,413
Income (loss) from operations	5,349	2,441	7,661	4,590
Total assets	144,592	112,117	144,592	112,117
Depreciation and amortization	1,158	1,283	2,351	2,477
Operating Segments [Member] | VI Chip [Member]
Segment Reporting Information [Line Items]
Net revenues	4,634	6,639	13,975	10,046
Income (loss) from operations	(9,406)	(8,349)	(16,253)	(17,587)
Total assets	16,942	17,667	16,942	17,667
Depreciation and amortization	788	807	1,579	1,708
Operating Segments [Member] | Picor [Member]
Segment Reporting Information [Line Items]
Net revenues	2,667	2,808	5,617	4,590
Income (loss) from operations	(785)	(811)	(1,527)	(2,015)
Total assets	4,560	4,790	4,560	4,790
Depreciation and amortization	105	111	206	219
Operating Segments [Member] | Corporate [Member]
Segment Reporting Information [Line Items]
Income (loss) from operations	(172)	(263)	(334)	(466)
Total assets	75,182	96,795	75,182	96,795
Depreciation and amortization	360	333	718	624
Eliminations [Member]
Segment Reporting Information [Line Items]
Net revenues	(1,825)	(2,793)	(4,572)	(4,238)
Total assets	$ (83,002)	$ (54,101)	$ (83,002)	$ (54,101)