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

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.

No definition available.

Name:	wern_LeaseholdImprovementstoLandTotalCostLessAccumulatedDepreciation
Namespace Prefix:	wern_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant