Note 10 - Revenue and Business Segments (Details Textual)	3 Months Ended
	Mar. 31, 2024 USD ($)	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($)
Number of Operating Segments	5
Number of Reportable Segments		4
Customer Contract Term (Year)	1 year
Capitalized Contract Cost, Impairment Loss	$ 0	$ 0
Prepaid Expenses and Other Current Assets [Member]
Contract with Customer, Asset, after Allowance for Credit Loss, Total	2,900,000		$ 2,100,000
Dedicated [Member]
Depreciation, Depletion and Amortization, Total	$ 10,300,000	11,800,000
Dedicated [Member] | Minimum [Member]
Customer Contract Term (Year)	3 years
Dedicated [Member] | Maximum [Member]
Customer Contract Term (Year)	5 years
Truckload [Member]
Depreciation, Depletion and Amortization, Total	$ 16,100,000	15,300,000
Intermodal [Member]
Depreciation, Depletion and Amortization, Total	1,600,000	1,900,000
Brokerage [Member]
Depreciation, Depletion and Amortization, Total	$ 521,000	$ 449,000