XML 1070 R52.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Retirement Plan - Additional Information (Detail) - USD ($) $ in Thousands | 12 Months Ended
--- | ---
Dec. 30, 2017 | Dec. 31, 2016 | Dec. 26, 2015
Retirement Plans [Line Items] |  |  |
Defined contribution plan maximum employee contribution as a percentage of base salary | 75.00% |  |
Expense for the Company-sponsored defined contribution plan | $ 2,056 | $ 2,074 | $ 1,901
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% |  |
Threshold to determine company matching percentage | 3.00% |  |
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% |  |
Threshold to determine company matching percentage | 2.00% |  |

X
- 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

X
- Definition Retirement Plans [Line Items] + References No definition available. + Details
Name: | lstr_RetirementPlansLineItems
Namespace Prefix: | lstr_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- 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

X
- Definition Amount of cost for defined contribution plan. + 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=49170846&loc=d3e28014-114942 + Details
Name: | us-gaap_DefinedContributionPlanCostRecognized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- 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

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=lstr_FirstThreePercentOfContributionsOnDefinedContributionPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanTypeAxis=lstr_NextTwoPercentOfContributionsOnDefinedContributionPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |