Income Taxes [Line Items]

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- Definition

Net unrecognized tax benefits.

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- Definition

Tax Cuts and Jobs Act of 2017, incomplete accounting, change in tax rate, deferred tax liability, provisional income tax benefit.

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- Definition

Tax cuts and jobs act of 2017 incomplete accounting deemed repatriation US federal taxes payable.

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Tax cuts and jobs act of 2017 incomplete accounting deemed repatriation US federal taxes payable period.

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Tax Cuts and Jobs Act of 2017, incomplete accounting, provisional undistributed accumulated earnings of foreign subsidiary.

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- Definition

Tax Cuts and Jobs Act of 2017, incomplete accounting, transition tax for accumulated foreign earnings, provisional income tax expense.

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- Definition

Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

+ References

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-Name Accounting Standards Codification
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- Definition

The amount of cash paid during the current period to foreign, federal, state, and local authorities as taxes on income.

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- Definition

The parent entity's interest in net assets of the subsidiary, expressed as a percentage.

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- Definition

Amount of the effect of a change in accounting principle on net income.

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- Definition

Amount accrued for interest on an underpayment of income taxes and penalties related to a tax position claimed or expected to be claimed in the tax return.

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Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 30, 2017	Dec. 31, 2016	Dec. 26, 2015
Income Taxes [Line Items]
Federal income tax rate		35.00%
Tax cuts and jobs act of 2017 incomplete accounting revaluation deferred tax liabilities provisional income tax expense (benefit)		$ 20,430
Tax cuts and jobs act of 2017 incomplete accounting deemed repatriation foreign earnings and profits provisional income tax expense (benefit)		17,981
Tax cuts and jobs act of 2017, incomplete accounting, provisional income tax expense (benefit)		900
Tax cuts and jobs act of 2017 incomplete accounting deemed repatriation US federal taxes payable		$ 500
Tax cuts and jobs act of 2017 incomplete accounting deemed repatriation US federal taxes payable period		8 years
Net unrecognized tax benefits		$ 3,670	$ 1,829
Accrued for estimated interest and penalties		627	547
Income taxes paid		$ 86,607	$ 69,067	$ 74,619
Scenario, Forecast
Income Taxes [Line Items]
Federal income tax rate	21.00%
Landstar Metro
Income Taxes [Line Items]
Ownership in subsidiaries, percentage		70.00%
Landstar Servicios
Income Taxes [Line Items]
Ownership in subsidiaries, percentage		70.00%
Accounting Standards Update 2016-09
Income Taxes [Line Items]
Excess tax benefit from stock-based awards		$ 1,299