Goodwill and Intangible Assets - Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	Dec. 27, 2014	Dec. 28, 2013
Summary of Finite-lived intangible assets
Adjusted cost	$ 30,670	$ 31,927
Accumulated amortization	(26,376)	(24,063)
Net carrying amount	4,294us-gaap_FiniteLivedIntangibleAssetsNet	7,864us-gaap_FiniteLivedIntangibleAssetsNet
Developed technology [Member]
Summary of Finite-lived intangible assets
Adjusted cost	16,950	18,095
Accumulated amortization	(12,991)	(11,032)
Net carrying amount	3,959	7,063
Customer relationships [Member]
Summary of Finite-lived intangible assets
Adjusted cost	9,461	9,573
Accumulated amortization	(9,449)	(9,263)
Net carrying amount	12	310
Brand names [Member]
Summary of Finite-lived intangible assets
Adjusted cost	1,927	1,927
Accumulated amortization	(1,802)	(1,700)
Net carrying amount	125	227
Patented technology [Member]
Summary of Finite-lived intangible assets
Adjusted cost	2,252	2,252
Accumulated amortization	(2,054)	(1,988)
Net carrying amount	198	264
Trademark [Member]
Summary of Finite-lived intangible assets
Adjusted cost	80	80
Accumulated amortization	(80)	(80)
Net carrying amount	$ 0	$ 0

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

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

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

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

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