Industry Segments - Financial Information by Industry Segment (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 30, 2013	Mar. 31, 2012
Net sales by segment:
Total consolidated net sales and net sales for reportable segments	$ 56,016	$ 53,296
Segment profit (loss):
Profit (loss) for reportable segments	(11,026)	(2,218)
Other unallocated amounts:
Corporate expenses	(1,903)	(1,489)
Interest and other, net	10	92
Loss before income taxes	(12,919)	(3,615)
Semiconductor equipment [Member]
Net sales by segment:
Total consolidated net sales and net sales for reportable segments	48,584	43,673
Segment profit (loss):
Profit (loss) for reportable segments	(8,861)	(1,707)
Microwave communications [Member]
Net sales by segment:
Total consolidated net sales and net sales for reportable segments	3,643	6,778
Segment profit (loss):
Profit (loss) for reportable segments	(2,372)	125
Video cameras [Member]
Net sales by segment:
Total consolidated net sales and net sales for reportable segments	3,789	2,845
Segment profit (loss):
Profit (loss) for reportable segments	$ 207	$ (636)