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Cash and Investments - Additional Information (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 29, 2018 | Dec. 30, 2017 | Dec. 31, 2016
Investments Debt And Equity Securities [Abstract] |  |  |
Net realized gains on sale of securities | $ 1.4 | $ 1.3 | $ 0.5
Investment effective maturity period, less than | 3 years | 3 years |

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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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- Definition Amount of realized gain (loss) on investment in marketable security, including other-than-temporary impairment (OTTI). + References No definition available. + Details
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