Note 10 - Commitments and Contingencies (Details Textual)	Mar. 31, 2022 USD ($)
Lessee, Operating Lease, Liability, to be Paid, Total	$ 583,000
Capital Addition Purchase Commitments [Member] \| Revenue Equipment [Member]
Purchase Obligation, to be Paid, Remainder of Fiscal Year	38,600,000
Purchase Obligation, to be Paid, Year One	23,100,000
Capital Addition Purchase Commitments [Member] \| Building Construction [Member]
Purchase Obligation, to be Paid, Remainder of Fiscal Year	$ 5,800,000

Amount of purchase arrangement to be paid in next fiscal year following current fiscal year. Includes, but is not limited to, recorded and unrecorded purchase obligations, long-term purchase commitment, and short-term purchase commitment. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

No definition available.

Name:	us-gaap_PurchaseObligationDueInNextTwelveMonths
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant