Segment Information - Additional Information (Detail)	3 Months Ended	6 Months Ended
Jun. 30, 2012 Customer	Jun. 25, 2011 Customer	Jun. 30, 2012 Customer	Jun. 25, 2011 Customer
Segment Reporting Information [Line Items]
Number of customers accounting for 10 percent or more of total revenue	0	0	0	0
No single customer accounted for benchmark percentage to be considered major customer	10.00%	10.00%	10.00%	10.00%

Percentage of revenue generated from a single external customer that accounts for 10 percent or more of an entity's revenues.

No definition available.

Name:	lstr_EntityWideRevenueNoMajorCustomerAccountedForBenchmarkPercentage
Namespace Prefix:	lstr_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration