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Investments - Additional Information (Detail) - USD ($) | 6 Months Ended |
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Jun. 26, 2021 | Dec. 26, 2020
Debt Securities, Available-for-sale [Line Items] |  |
Investments maximum maturity period | 5 years |
Unrealized gain (loss), net of unrealized gains/losses, on the investments in the bond portfolio | $ 2,452,000 | $ 3,578,000

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- Definition Amount before tax of unrealized gain (loss) in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale. + References No definition available. + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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