Note 5 - Segment Reporting - Segment Reporting Information, by Segment (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Trucking [Member] | Operating Segments [Member]
Revenues	[1]	$ 85,369	$ 108,440	$ 275,617	$ 317,664
Operating income (loss)		2,460	2,176	6,565	(6,338)
Depreciation and amortization		8,608	10,746	29,733	33,257
Trucking [Member] | Intersegment Eliminations [Member]
Revenues		(387)	(122)	(1,421)	(434)
Trucking [Member]
Revenues		84,982	108,318	274,196	317,230
S C S [Member] | Operating Segments [Member]
Revenues		39,505	49,359	119,781	144,507
Operating income (loss)		2,999	5,336	9,234	16,405
Depreciation and amortization		94	46	218	138
S C S [Member] | Intersegment Eliminations [Member]
Revenues		(997)	(4,059)	(4,027)	(9,332)
S C S [Member]
Revenues		38,508	45,300	115,754	135,175
Revenues		123,490	153,618	389,950	452,405
Operating income (loss)		5,459	7,512	15,799	10,067
Depreciation and amortization		$ 8,702	$ 10,792	$ 29,951	$ 33,395

[1] Includes foreign revenue of $10.7 million and $32.5 million for the three and nine months ended September 30, 2015, respectively, and $14.6 million and $45.0 million for the three and nine months ended September 30, 2014, respectively. All foreign revenue is paid in US dollars.