Industry Segments - Financial Information by Industry Segment (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 28, 2015	Mar. 29, 2014
Net sales by segment:
Consolidated net sales for reportable segments	$ 68,068us-gaap_SalesRevenueNet	$ 64,864us-gaap_SalesRevenueNet
Segment profit (loss):
Profit (loss) for reportable segments	310	(1,364)
Other unallocated amounts:
Corporate expenses	(2,015)	(2,059)
Interest and other, net	6us-gaap_InvestmentIncomeNet	15us-gaap_InvestmentIncomeNet
Loss from continuing operations before taxes	(1,699)	(3,408)
Semiconductor Equipment [Member]
Net sales by segment:
Consolidated net sales for reportable segments	63,447	60,170
Segment profit (loss):
Profit (loss) for reportable segments	1,236	(825)
Microwave Communications Equipment [Member]
Net sales by segment:
Consolidated net sales for reportable segments	4,621	4,694
Segment profit (loss):
Profit (loss) for reportable segments	$ (926)	$ (539)

Segment reporting information segment profit loss.

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- Definition

This element represents the income or loss from continuing operations attributable to the economic entity which may also be defined as revenue less expenses from ongoing operations, after income or loss from equity method investments, but before income taxes, extraordinary items, and noncontrolling interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 10

-Article 5

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Sum of operating profit and nonoperating income or expense before Income or Loss from equity method investments, income taxes, extraordinary items, and noncontrolling interest.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 235

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.4-08.(h)(1)(i))

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- Definition

Amount after accretion (amortization) of discount (premium), and investment expense, of interest income and dividend income on nonoperating securities.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.8)

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-Name Accounting Standards Codification

-Topic 225

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-Section S99

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- Definition

The sum of expenses not otherwise specified in the taxonomy for managing and administering the affairs of an entity, including affiliates of the reporting entity, which are not directly or indirectly associated with the manufacture, sale or creation of a product or product line.

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- Definition

Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

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