Note 4 - Segment Reporting - Segment Reporting Information by Segment (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Revenues		$ 135,381	$ 107,358	$ 260,394	$ 209,028
Operating loss		4,311	(2,966)	6,703	(9,365)
Depreciation and amortization		7,477	6,879	14,657	14,523
Trucking [Member]
Revenues		85,569	71,545	164,302	141,825
USAT Logistics [Member]
Revenues		49,812	35,813	96,092	67,203
Operating Segments [Member] | Trucking [Member]
Revenues	[1]	85,685	71,731	164,531	142,202
Operating loss		2,153	(4,843)	1,689	(11,971)
Depreciation and amortization		7,299	6,759	14,325	14,323
Operating Segments [Member] | USAT Logistics [Member]
Revenues		50,616	36,878	97,391	69,528
Operating loss		2,158	1,877	5,014	2,606
Depreciation and amortization		178	120	332	200
Intersegment Eliminations [Member] | Trucking [Member]
Revenues		(116)	(186)	(229)	(377)
Intersegment Eliminations [Member] | USAT Logistics [Member]
Revenues		$ (804)	$ (1,065)	$ (1,299)	$ (2,325)

[1] Includes foreign revenue of $11.0 million and $20.9 million for the three and six months ended June 30, 2018, respectively, and $9.1 million and $17.9 million for the three and six months ended June 30, 2017, respectively. All foreign revenue is collected in U.S. dollars.