Note 15 - Segment Information - Segment Information (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenue	$ 225,229	$ 210,830	$ 191,689	$ 210,813	$ 230,555	$ 220,459	$ 217,040	$ 217,333	$ 838,561	$ 885,387	$ 880,417
Operating (loss) income	$ 9,566	$ 6,811	$ (28,950)	$ (1,454)	$ 1,663	$ (3,870)	$ 7,030	$ 3,946	(14,027)	8,769	55,416
Dedicated [Member]
Revenue									288,652	342,473	257,739
Managed Freight [Member]
Revenue									177,579	138,616	129,790
Operating Segments [Member]
Revenue									838,561	885,387	880,417
Operating (loss) income									(14,027)	8,769	55,416
Depreciation and amortization									65,472	80,502	75,843
Operating Segments [Member] | Highway Services [Member]
Revenue									320,202	356,521	469,308
Operating (loss) income									(7,038)	(1,260)	32,693
Depreciation and amortization									31,969	39,371	44,564
Operating Segments [Member] | Dedicated [Member]
Revenue									288,652	342,473	257,739
Operating (loss) income									(15,534)	1,188	12,699
Depreciation and amortization									29,610	38,716	30,604
Operating Segments [Member] | Managed Freight [Member]
Revenue									177,579	138,616	129,790
Operating (loss) income									4,482	3,323	7,150
Depreciation and amortization									829	418	286
Operating Segments [Member] | Factoring [Member]
Revenue									52,128	47,777	23,580
Operating (loss) income									4,063	5,518	2,874
Depreciation and amortization									3,064	1,997	389
Intersegment Eliminations [Member]
Revenue									11,630	10,302	7,298
Intersegment Eliminations [Member] | Highway Services [Member]
Revenue									11,630	10,302	7,298
Intersegment Eliminations [Member] | Dedicated [Member]
Revenue									0	0	0
Intersegment Eliminations [Member] | Managed Freight [Member]
Revenue									0	0	0
Intersegment Eliminations [Member] | Factoring [Member]
Revenue									0	0	0
Consolidation, Eliminations [Member]
Revenue									$ (11,630)	$ (10,302)	$ (7,298)