Note 12 - Business Segments (Details Textual)	3 Months Ended		9 Months Ended
	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)	Sep. 30, 2015 USD ($)	Sep. 30, 2014 USD ($)
Truckload [Member]
Depreciation, Depletion and Amortization	$ 13,300,000	$ 13,200,000	$ 40,000,000	$ 39,700,000
Dedicated [Member]
Depreciation, Depletion and Amortization	4,300,000	2,300,000	10,400,000	5,600,000
Intermodal [Member]
Depreciation, Depletion and Amortization	1,400,000	1,600,000	4,300,000	4,500,000
Brokerage [Member]
Depreciation, Depletion and Amortization	$ 295,000	$ 247,000	$ 854,000	$ 711,000
Number of Operating Segments			6
Number of Reportable Segments			4	2