Segment Information - Significant Segment Financial Data (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Segment Reporting Information [Line Items]
Net revenues	$ 58,402	$ 55,091	$ 164,996	$ 143,902
Income (loss) from operations	(4,132)	(1,355)	(14,585)	(16,833)
Total assets	158,719	180,878	158,719	180,878	165,640
Depreciation and amortization	2,459	2,527	7,313	7,555
Operating Segments [Member] | BBU [Member]
Segment Reporting Information [Line Items]
Net revenues	45,972	42,331	137,546	120,743
Income (loss) from operations	2,369	5,162	10,030	9,752
Total assets	149,125	119,739	149,125	119,739
Depreciation and amortization	1,155	1,296	3,506	3,773
Operating Segments [Member] | VI Chip [Member]
Segment Reporting Information [Line Items]
Net revenues	10,321	12,457	24,296	22,503
Income (loss) from operations	(6,429)	(5,555)	(22,682)	(23,142)
Total assets	18,876	19,898	18,876	19,898
Depreciation and amortization	850	760	2,429	2,468
Operating Segments [Member] | Picor [Member]
Segment Reporting Information [Line Items]
Net revenues	4,081	2,836	9,698	7,426
Income (loss) from operations	156	(696)	(1,371)	(2,711)
Total assets	4,945	4,345	4,945	4,345
Depreciation and amortization	103	96	309	315
Operating Segments [Member] | Corporate [Member]
Segment Reporting Information [Line Items]
Income (loss) from operations	(228)	(266)	(562)	(732)
Total assets	77,397	98,614	77,397	98,614
Depreciation and amortization	351	375	1,069	999
Eliminations [Member]
Segment Reporting Information [Line Items]
Net revenues	(1,972)	(2,533)	(6,544)	(6,770)
Total assets	$ (91,624)	$ (61,718)	$ (91,624)	$ (61,718)