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v2.4.1.9

Retirement Plan - Additional Information (Detail) (USD $) | 12 Months Ended
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Dec. 27, 2014 | Dec. 28, 2013 | Dec. 29, 2012
Retirement Plans [Line Items] |  |  |
Defined contribution plan maximum employee contribution as a percentage of base salary | 75.00%us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent |  |
Expense from continuing operations for the Company-sponsored defined contribution plan | $ 1,718,000 us-gaap_DefinedContributionPlanCostRecognized | $ 1,693,000 us-gaap_DefinedContributionPlanCostRecognized | $ 1,660,000 us-gaap_DefinedContributionPlanCostRecognized
First 3% of Contributions on Defined Contribution Plan |  |  |
Retirement Plans [Line Items] |  |  |
Defined contribution plan employer contribution as a percentage of base salary | 100.00%lstr_DefinedContributionPlanEmployerContributionAsPercentageOfBaseSalary / lstr_DefinedContributionPlansDisclosureAxis = lstr_FirstThreePercentOfContributionsOnDefinedContributionPlanMember |  |
Threshold to determine company matching percentage | 3.00%lstr_ThresholdToDetermineCompanyMatchingPercentage / lstr_DefinedContributionPlansDisclosureAxis = lstr_FirstThreePercentOfContributionsOnDefinedContributionPlanMember |  |
Next 2% of Contributions on Defined Contribution Plan |  |  |
Retirement Plans [Line Items] |  |  |
Defined contribution plan employer contribution as a percentage of base salary | 50.00%lstr_DefinedContributionPlanEmployerContributionAsPercentageOfBaseSalary / lstr_DefinedContributionPlansDisclosureAxis = lstr_NextTwoPercentOfContributionsOnDefinedContributionPlanMember |  |
Threshold to determine company matching percentage | 2.00%lstr_ThresholdToDetermineCompanyMatchingPercentage / lstr_DefinedContributionPlansDisclosureAxis = lstr_NextTwoPercentOfContributionsOnDefinedContributionPlanMember |  |

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- Definition Defined contribution plan employer contribution as a percentage of base salary + References No definition available. + Details
Name: | lstr_DefinedContributionPlanEmployerContributionAsPercentageOfBaseSalary
Namespace Prefix: | lstr_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

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- Details
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Namespace Prefix: | lstr_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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- Definition Threshold to determine company matching percentage. + References No definition available. + Details
Name: | lstr_ThresholdToDetermineCompanyMatchingPercentage
Namespace Prefix: | lstr_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

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- Definition The amount of the cost recognized during the period for defined contribution plans. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 70 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6414718&loc=d3e28014-114942 + Details
Name: | us-gaap_DefinedContributionPlanCostRecognized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

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- Definition Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan. + References No definition available. + Details
Name: | us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeePercent
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

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- Details
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Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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- Details
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Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |