Goodwill and Acquired Intangibles (Details 2) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Oct. 03, 2015	Sep. 27, 2014	Oct. 03, 2015	Sep. 27, 2014
Amortization of acquired intangibles
Cost of product and maintenance	$ 10,107	$ 10,071	$ 30,385	$ 26,260
Amortization of acquired intangibles	5,687	6,316	18,037	17,105
Total amortization of acquired intangibles	$ 15,794	$ 16,387	$ 48,422	$ 43,365

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

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-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

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-Section 45

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-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

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-Section 50

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

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