Industry Segments - Financial Information by Industry Segment (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 29, 2014	Mar. 30, 2013
Net sales by segment:
Total consolidated net sales and net sales for reportable segments	$ 68,417	$ 56,016
Segment profit (loss):
Loss for reportable segments	(1,243)	(11,026)
Other unallocated amounts:
Corporate expenses	(2,175)	(1,903)
Interest and other, net	15	10
Loss before taxes	(3,403)	(12,919)
Semiconductor Equipment [Member]
Net sales by segment:
Total consolidated net sales and net sales for reportable segments	60,170	48,584
Segment profit (loss):
Loss for reportable segments	(825)	(8,861)
Microwave Communications [Member]
Net sales by segment:
Total consolidated net sales and net sales for reportable segments	4,694	3,643
Segment profit (loss):
Loss for reportable segments	(539)	(2,372)
Video Cameras [Member]
Net sales by segment:
Total consolidated net sales and net sales for reportable segments	3,553	3,789
Segment profit (loss):
Loss for reportable segments	$ 121	$ 207