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           Intangible Assets (Details 1) (USD $) 
        In Thousands, unless otherwise specified  | 
        3 Months Ended | |
|---|---|---|
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           Mar. 30, 2013 
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           Mar. 31, 2012 
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| Summary of amortization expense for acquired intangibles | ||
| Amortization Expense | $ 468 | $ 350 | 
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- Definition 
          The aggregate expense charged against earnings to allocate the cost of acquired intangible assets. As a noncash expense, this element is added back to net income when calculating cash provided by (used in) operations using the indirect method. No definition available. 
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- Details 
          
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