XML 78 R63.htm IDEA: XBRL DOCUMENT
v3.20.4

Related Party Transactions (Details) - Principal Stockholder [Member] | 12 Months Ended
--- | ---
Dec. 31, 2020 USD ($)
Related Party Transaction [Line Items] |
Lease annual rent payments | $ 1.00
Leasehold improvements to land, total cost | 7,000,000.0
Leasehold improvements to land, total cost less accumulated depreciation | $ 2,400,000

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_RelatedPartyTransactionLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of annual payment for rental of land from related party. + References No definition available. + Details
Name: | wern_LeaseAnnualRentPayments
Namespace Prefix: | wern_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Gross amount, at the balance sheet date, of long-lived, depreciable assets that are an addition or improvement to assets held under lease arrangement with related party. + References No definition available. + Details
Name: | wern_LeaseholdImprovementstoLandTotalCost
Namespace Prefix: | wern_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Cost, less accumulated depreciation amount, at the balance sheet date, of long-lived, depreciable assets that are an addition or improvement to assets held under lease arrangement with related party. + References No definition available. + Details
Name: | wern_LeaseholdImprovementstoLandTotalCostLessAccumulatedDepreciation
Namespace Prefix: | wern_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=us-gaap_PrincipalOwnerMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |