Note 10 - Commitments and Contingencies (Details Textual)	Sep. 30, 2021 USD ($)
Lessee, Operating Lease, Liability, to be Paid, Total	$ 670,000
Capital Addition Purchase Commitments [Member] | Revenue Equipment [Member]
Purchase Obligation, to be Paid, Remainder of Fiscal Year	16,500,000
Capital Addition Purchase Commitments [Member] | Building Construction [Member]
Purchase Obligation, to be Paid, Remainder of Fiscal Year	$ 2,900,000