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

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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Revenue, Gross Profit by Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Oct. 02, 2015	Jul. 03, 2015	Apr. 03, 2015	Dec. 31, 2014	Sep. 26, 2014	Jun. 27, 2014	Mar. 28, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Revenue	$ 90,219	$ 92,271	$ 96,494	$ 94,614	$ 94,012	$ 94,656	$ 96,905	$ 79,133	$ 373,598	$ 364,706	$ 316,910
Gross Profit	$ 36,629	$ 39,910	$ 41,345	$ 40,006	$ 39,728	$ 39,683	$ 38,651	$ 32,105	157,890	150,167	132,227
Laser Products
Segment Reporting Information [Line Items]
Revenue									168,331	177,726	166,598
Gross Profit									73,602	74,224	68,819
Vision Technologies
Segment Reporting Information [Line Items]
Revenue									124,725	122,187	90,276
Gross Profit									48,966	48,678	35,824
Precision Motion
Segment Reporting Information [Line Items]
Revenue									80,542	64,793	60,036
Gross Profit									36,709	28,333	27,778
Unallocated Corporate and Shared Services
Segment Reporting Information [Line Items]
Gross Profit									$ (1,387)	$ (1,068)	$ (194)