Details of Finite-lived Intangible Assets by Segment (Detail) - USD ($) $ in Thousands	Sep. 29, 2018	Dec. 30, 2017
Finite-Lived Intangible Assets [Line Items]
Finite Lived, Gross Carrying Amount	$ 8,387
Accumulated Amortization	(7,345)	$ (6,884)
Finite Lived, Net Carrying Amount	1,042	$ 1,503
TFE
Finite-Lived Intangible Assets [Line Items]
Finite Lived, Gross Carrying Amount	7,172
Accumulated Amortization	(6,220)
Finite Lived, Net Carrying Amount	952
Photonics
Finite-Lived Intangible Assets [Line Items]
Finite Lived, Gross Carrying Amount	1,215
Accumulated Amortization	(1,125)
Finite Lived, Net Carrying Amount	$ 90

Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

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- Definition

Amount before amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 928
-SubTopic 340
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6473545&loc=d3e61844-108004

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 30
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275

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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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- Definition

Amount after amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life.

+ References

+ Details

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