Note 3 - Goodwill and Other Purchased Intangible Assets (Details Textual) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 26, 2015	Sep. 27, 2014	Sep. 26, 2015	Sep. 27, 2014	Dec. 27, 2014
Rasco Technology [Member] \| Trade Names [Member]
Indefinite-Lived Intangible Assets (Excluding Goodwill)	$ 1.9		$ 1.9		$ 2.1
Intangible Assets, Percentage of Fair Value in Excess of Carrying Amount	4.00%		4.00%
Ismeca Semiconductor Holding Sa [Member] \| Trade Names [Member]
Indefinite-Lived Intangible Assets (Excluding Goodwill)	$ 3.7		$ 3.7		$ 3.6
Intangible Assets, Percentage of Fair Value in Excess of Carrying Amount	17.00%		17.00%
Amortization of Intangible Assets	$ 1.7	$ 2.0	$ 5.3	$ 6.0

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6388964&loc=d3e16225-109274

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(2)

-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275

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