Subsidiary Wind Down - Additional Information (Detail) $ in Thousands	6 Months Ended
Jun. 27, 2026 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Description and Timing of Disposal	During the second fiscal quarter of 2026, the Company stopped actively marketing Landstar Metro and initiated a wind-down of its operations and sales of certain assets. As such, the assets and liabilities of Landstar Metro are no longer presented as held for sale within the consolidated balance sheet at June 27, 2026.
Location, Statement of Income, Balance [Axis]: SellingGeneralAndAdministrativeExpense
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Impairment of Long-Lived Assets to be Disposed of	$ 679,000

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.

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+ Details