Goodwill and Intangible Assets - Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	Mar. 28, 2015	Dec. 27, 2014
Summary of Finite-lived intangible assets
Adjusted cost	$ 29,684	$ 30,670
Accumulated amortization	(26,358)	(26,376)
Net carrying amount	3,326us-gaap_FiniteLivedIntangibleAssetsNet	4,294us-gaap_FiniteLivedIntangibleAssetsNet
Developed technology [Member]
Summary of Finite-lived intangible assets
Adjusted cost	16,063	16,950
Accumulated amortization	(13,018)	(12,991)
Net carrying amount	3,045	3,959
Customer relationships [Member]
Summary of Finite-lived intangible assets
Adjusted cost	9,362	9,461
Accumulated amortization	(9,362)	(9,449)
Net carrying amount	0	12
Brand names [Member]
Summary of Finite-lived intangible assets
Adjusted cost	1,927	1,927
Accumulated amortization	(1,827)	(1,802)
Net carrying amount	100	125
Patented technology [Member]
Summary of Finite-lived intangible assets
Adjusted cost	2,252	2,252
Accumulated amortization	(2,071)	(2,054)
Net carrying amount	181	198
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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