Segment Information - Information About Segments (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 30, 2014	Mar. 31, 2013
Segment Reporting Information [Line Items]
Product revenue	$ 83,569	$ 74,672
Service revenue	7,360	6,220
Operating income	22,443	17,981
Operating Segments | MVSD
Segment Reporting Information [Line Items]
Product revenue	77,618	68,319
Service revenue	3,698	2,092
Operating income	28,292	22,076
Operating Segments | SISD
Segment Reporting Information [Line Items]
Product revenue	5,951	6,353
Service revenue	3,662	4,128
Operating income	1,013	1,732
Reconciling Items
Segment Reporting Information [Line Items]
Operating income	$ (6,862)	$ (5,827)