BASIS OF PRESENTATION (Details) $ in Millions	3 Months Ended
Mar. 31, 2022 USD ($)
BASIS OF PRESENTATION
Increase or (decrease) in depreciation expense from a change in the tractor fleet salvage	$ (0.9)

The increase or decrease in expense from a change in the tractor fleet salvage.

No definition available.

Name:	usak_IncreaseDecreaseInDepreciationExpenseFromChangeInTractorFleetSalvageValue
Namespace Prefix:	usak_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration