Note 4 - Segment Reporting (Details) - Segment Reporting Information, by Segment (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Base Revenue
Base revenue	$ 124,969	$ 111,462	$ 242,580	$ 216,350
Fuel Surcharge Revenue
Fuel surcharge revenue	28,329	28,276	56,207	55,416
Total revenue	153,298	139,738	298,787	271,766
Operating Income (Loss)
Operating loss	4,257	(945)	3,214	(3,771)
Depreciation and Amortization
Depreciation and amortization	11,148	10,852	22,603	21,767
Operating Segments [Member] | Trucking [Member]
Base Revenue
Base revenue	83,353	81,441	163,689	161,244
Fuel Surcharge Revenue
Fuel surcharge revenue	22,957	23,392	45,535	45,615
Operating Income (Loss)
Operating loss	(1,734)	(3,108)	(7,855)	(7,086)
Depreciation and Amortization
Depreciation and amortization	10,567	10,198	21,432	20,452
Operating Segments [Member] | SCS [Member]
Base Revenue
Base revenue	43,918	31,434	83,323	58,222
Fuel Surcharge Revenue
Fuel surcharge revenue	5,978	5,260	11,825	10,638
Operating Income (Loss)
Operating loss	5,991	2,163	11,069	3,315
Depreciation and Amortization
Depreciation and amortization	44	62	92	141
Intersegment Eliminations [Member]
Base Revenue
Base revenue	(2,302)	(1,413)	(4,432)	(3,116)
Fuel Surcharge Revenue
Fuel surcharge revenue	(606)	(376)	(1,153)	(837)
Corporate, Non-Segment [Member]
Depreciation and Amortization
Depreciation and amortization	$ 537	$ 592	$ 1,079	$ 1,174