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Cash and Investments - Textual (Details) | 9 Months Ended | 12 Months Ended
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Sep. 28, 2019 | Dec. 29, 2018
Investments Debt And Equity Securities [Abstract] |  |
Investment maturity period, less than | 34 months | 34 months

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- Definition Investment maturity period, maximum. + References No definition available. + Details
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- References No definition available. + Details
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