XML 68 R46.htm IDEA: XBRL DOCUMENT
v3.3.1.900

Schedule of Unrealized Loss on Available for Sale Investments (Detail) - USD ($) $ in Thousands | Dec. 26, 2015 | Dec. 27, 2014
--- | --- | ---
Schedule of Available-for-sale Securities [Line Items] |  |
Available-for-sale investments with unrealized losses, Less than 12 months, Fair Value | $ 58,791 | $ 28,352
Available-for-sale investments with unrealized losses, Less than 12 months, Unrealized Loss | 288 | 149
Available-for-sale investments with unrealized losses, 12 months or longer, Fair Value | 562 | 14,580
Available-for-sale investments with unrealized losses, 12 months or longer, Unrealized Loss | 53 | 194
Available-for-sale investments with unrealized losses, Fair Value, Total | 59,353 | 42,932
Available-for-sale investments with unrealized losses, Unrealized Loss, Total | 341 | 343
Asset-backed securities |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Available-for-sale investments with unrealized losses, Less than 12 months, Fair Value | 4,422 | 2,006
Available-for-sale investments with unrealized losses, Less than 12 months, Unrealized Loss | 58 | 13
Available-for-sale investments with unrealized losses, 12 months or longer, Fair Value |  | 2,447
Available-for-sale investments with unrealized losses, 12 months or longer, Unrealized Loss |  | 37
Available-for-sale investments with unrealized losses, Fair Value, Total | 4,422 | 4,453
Available-for-sale investments with unrealized losses, Unrealized Loss, Total | 58 | 50
Corporate bonds and direct obligations of government agencies |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Available-for-sale investments with unrealized losses, Less than 12 months, Fair Value | 39,276 | 19,354
Available-for-sale investments with unrealized losses, Less than 12 months, Unrealized Loss | 217 | 135
Available-for-sale investments with unrealized losses, 12 months or longer, Fair Value | 562 | 11,373
Available-for-sale investments with unrealized losses, 12 months or longer, Unrealized Loss | 53 | 149
Available-for-sale investments with unrealized losses, Fair Value, Total | 39,838 | 30,727
Available-for-sale investments with unrealized losses, Unrealized Loss, Total | 270 | 284
U.S. Treasury Obligations |  |
Schedule of Available-for-sale Securities [Line Items] |  |
Available-for-sale investments with unrealized losses, Less than 12 months, Fair Value | 15,093 | 6,992
Available-for-sale investments with unrealized losses, Less than 12 months, Unrealized Loss | 13 | 1
Available-for-sale investments with unrealized losses, 12 months or longer, Fair Value |  | 760
Available-for-sale investments with unrealized losses, 12 months or longer, Unrealized Loss |  | 8
Available-for-sale investments with unrealized losses, Fair Value, Total | 15,093 | 7,752
Available-for-sale investments with unrealized losses, Unrealized Loss, Total | $ 13 | $ 9

X
- Definition Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale that have been in a continuous loss position for twelve months or longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27290-111563 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27337-111563 + Details
Name: | us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAccumulatedLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale in a continuous loss position. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27337-111563 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27290-111563 + Details
Name: | us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This item represents the aggregate fair value of investments in debt and equity securities in an unrealized loss position which are categorized neither as held-to-maturity nor trading securities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27290-111563 + Details
Name: | us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale that have been in a continuous loss position for less than twelve months. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27290-111563 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27337-111563 + Details
Name: | us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAccumulatedLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This item represents the aggregate fair value of investments in debt and equity securities categorized neither as held-to-maturity nor trading securities that have been in a continuous unrealized loss position for less than twelve months. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27337-111563 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27290-111563 + Details
Name: | us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This item represents the aggregate fair value of investments in debt and equity securities categorized neither as held-to-maturity nor trading securities that have been in a continuous unrealized loss position for twelve months or longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27290-111563 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27337-111563 + Details
Name: | us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_AssetBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=lstr_CorporateBondsAndDirectObligationsOfGovernmentAgenciesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_USTreasurySecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |