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Summary of Significant Accounting Policies - Fair Value Hierarchy for Financial Assets (Detail) (Recurring [Member], USD $)
In Thousands, unless otherwise specified |
Jun. 29, 2013
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Dec. 29, 2012
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|---|---|---|
| Fair value hierarchy for financial assets | ||
| Total | $ 36,797 | $ 33,622 |
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U.S. Treasuries [Member]
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| Fair value hierarchy for financial assets | ||
| Total | 34,999 | 31,999 |
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Money Market funds [Member]
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| Fair value hierarchy for financial assets | ||
| Total | 1,798 | 1,623 |
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Level 1 [Member]
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| Fair value hierarchy for financial assets | ||
| Total | 36,797 | 33,622 |
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Level 1 [Member] | U.S. Treasuries [Member]
|
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| Fair value hierarchy for financial assets | ||
| Total | 34,999 | 31,999 |
|
Level 1 [Member] | Money Market funds [Member]
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| Fair value hierarchy for financial assets | ||
| Total | 1,798 | 1,623 |
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Level 2 [Member]
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| Fair value hierarchy for financial assets | ||
| Total | ||
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Level 2 [Member] | U.S. Treasuries [Member]
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| Fair value hierarchy for financial assets | ||
| Total | ||
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Level 2 [Member] | Money Market funds [Member]
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| Fair value hierarchy for financial assets | ||
| Total | ||
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Level 3 [Member]
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| Fair value hierarchy for financial assets | ||
| Total | ||
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Level 3 [Member] | U.S. Treasuries [Member]
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| Fair value hierarchy for financial assets | ||
| Total | ||
|
Level 3 [Member] | Money Market funds [Member]
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| Fair value hierarchy for financial assets | ||
| Total |