Revenue, Gross Profit and Gross Profit Margin by Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended
Apr. 01, 2016	Apr. 03, 2015
Segment Reporting Information [Line Items]
Revenue	$ 90,316	$ 94,614
Gross Profit	$ 36,892	$ 40,006
Gross profit margin percentage	40.80%	42.30%
Laser Products
Segment Reporting Information [Line Items]
Revenue	$ 40,358	$ 44,955
Gross Profit	$ 17,997	$ 19,375
Gross profit margin percentage	44.60%	43.10%
Vision Technologies
Segment Reporting Information [Line Items]
Revenue	$ 28,862	$ 31,111
Gross Profit	$ 9,579	$ 12,513
Gross profit margin percentage	33.20%	40.20%
Precision Motion
Segment Reporting Information [Line Items]
Revenue	$ 21,096	$ 18,548
Gross Profit	$ 9,668	$ 8,465
Gross profit margin percentage	45.80%	45.60%
Unallocated Corporate and Shared Services
Segment Reporting Information [Line Items]
Gross Profit	$ (352)	$ (347)

Percentage of aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity over amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process.

No definition available.

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- Definition

Aggregate revenue less cost of goods and services sold or operating expenses directly attributable to the revenue generation activity.

+ References

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 210.5-03.1,2)
-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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- Definition

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

+ References

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 210.5-03.1)
-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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