| Goodwill and Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified | 3 Months Ended | 
|---|---|
| Mar. 28, 2015 | |
| Summary of changes in goodwill | |
| Goodwill, Beginning Balance | $ 5,141us-gaap_Goodwill | 
| Acquisitions | 0us-gaap_GoodwillAcquiredDuringPeriod | 
| Currency translation | (80)us-gaap_GoodwillTranslationAdjustments | 
| Goodwill, Ending Balance | $ 5,061us-gaap_Goodwill | 
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- Definition Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Details 
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- Definition Amount of increase (decrease) from foreign currency translation adjustments of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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