Segment and Related Information - Financial Information by Industry Segment (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 29, 2012	Sep. 29, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 24, 2011	Jun. 25, 2011	Mar. 26, 2011	Dec. 29, 2012	Dec. 31, 2011	Dec. 25, 2010
Net sales by segment:
Total consolidated net sales and net sales for reportable segments	$ 50,714	$ 57,748	$ 59,404	$ 53,296	$ 66,559	$ 71,813	$ 80,896	$ 89,700	$ 221,162	$ 308,968	$ 322,667
Segment profit (loss):
Profit (loss) for reportable segments									(6,299)	22,357	33,894
Corporate expenses									(7,785)	(5,021)	(4,217)
Interest and other income									967	442	561
Income (loss) before income taxes									(13,117)	17,778	30,238
Total Depreciation expense									5,346	5,422	4,929
Intangible amortization									4,057	4,645	6,059
Total depreciation and amortization for reportable segments									9,403	10,067	10,988
Total consolidated capital expenditures									3,267	1,413	4,579
Semiconductor equipment [Member]
Net sales by segment:
Total consolidated net sales and net sales for reportable segments									179,449	260,648	273,566
Segment profit (loss):
Profit (loss) for reportable segments									(5,331)	20,040	29,654
Total Depreciation expense									4,506	4,313	3,596
Total consolidated capital expenditures									2,759	991	3,973
Microwave communications [Member]
Net sales by segment:
Total consolidated net sales and net sales for reportable segments									26,863	29,967	31,705
Segment profit (loss):
Profit (loss) for reportable segments									(847)	1,510	3,679
Total Depreciation expense									652	893	1,096
Total consolidated capital expenditures									481	313	440
Video cameras [Member]
Net sales by segment:
Total consolidated net sales and net sales for reportable segments									14,850	18,353	17,396
Segment profit (loss):
Profit (loss) for reportable segments									(121)	807	561
Total Depreciation expense									188	216	237
Total consolidated capital expenditures									$ 27	$ 109	$ 166