Leverage Ratio Required

No definition available.

Name:	lstr_LeverageRatioRequired
Namespace Prefix:	lstr_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

- Definition

Line of Credit Facility Outstanding Stock Percentage that Should be Acquired to Trigger Event of Default

+ References

No definition available.

+ Details

Name:	lstr_LineOfCreditFacilityOutstandingStockPercentageThatShouldBeAcquiredToTriggerEventOfDefault
Namespace Prefix:	lstr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Reflects the calculation as of the balance sheet date of the average interest rate weighted by the amount of debt outstanding by type or by instrument at that time.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtWeightedAverageInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Amount borrowed under the credit facility as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

Name:	us-gaap_LineOfCreditFacilityAmountOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Identification of whether the entity has been in compliance with any credit facility debt covenants during the period.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityCovenantCompliance
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Date the credit facility terminates, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

Name:	us-gaap_LineOfCreditFacilityExpirationDate1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Date the credit facility first became available, in CCYY-MM-DD format.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityInitiationDate1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 129

-Paragraph 2, 4

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

Debt - Additional Information (Detail) (USD $)	3 Months Ended	9 Months Ended
Debt - Additional Information (Detail) (USD $)	Sep. 29, 2012	Sep. 29, 2012	Jun. 29, 2012
Revolving Credit Facilities
Debt Instrument [Line Items]
Credit facility, initiation date		Jun. 29, 2012
Credit facility, expiration date		Jun. 29, 2017
Credit facility, borrowing capacity	225,000,000	225,000,000	225,000,000
Credit Facility, borrowing			60,000,000
Weighed average Interest rate on borrowing	1.48%	1.48%
Revolving Credit Facilities \| Minimum
Debt Instrument [Line Items]
Credit facility, unused credit commitment fee	0.15%
Credit facility event of default, minimum percentage that a person or group should acquire outstanding capital stock	25.00%	25.00%	25.00%
Credit facility, debt covenants compliance		The Company is currently in compliance with all of the debt covenants under the Credit Agreement
Revolving Credit Facilities \| Maximum
Debt Instrument [Line Items]
Credit facility, unused credit commitment fee	0.35%
Revolving Credit Facilities \| Maximum \| Maximum Leverage ration beyond which amount of cash dividends and other distributions to stockholders is limited
Debt Instrument [Line Items]
Leverage Ratio		2.5
Letter of Credit
Debt Instrument [Line Items]
Credit facility, borrowing capacity	75,000,000	75,000,000	75,000,000
Prior Credit Agreement
Debt Instrument [Line Items]
Credit Facility, borrowing			60,000,000