Note 12 - Business Segments - Operating Revenue and Operating Income by Segment (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Revenue, Net of Fuel Surcharge [Member] \| Truckload [Member]
Operating revenue	$ 88,822	$ 90,316	$ 175,633	$ 177,118
Revenue, Net of Fuel Surcharge [Member] \| Dedicated [Member]
Operating revenue	22,601	11,845	42,464	22,573
Revenue, Net of Fuel Surcharge [Member] \| Intermodal [Member]
Operating revenue	2,945	5,800	6,318	11,136
Fuel Surcharge Revenue [Member] \| Truckload [Member]
Operating revenue	13,929	23,699	28,519	47,411
Fuel Surcharge Revenue [Member] \| Dedicated [Member]
Operating revenue	2,803	3,245	5,394	6,067
Fuel Surcharge Revenue [Member] \| Intermodal [Member]
Operating revenue	16,101	20,406	33,120	38,760
Intermodal [Member]
Operating revenue	19,046	26,206	39,438	49,896
Brokerage [Member]
Operating revenue	16,387	13,112	33,427	24,767
Truckload [Member]
Operating revenue	102,751	114,015	204,152	224,529
Operating income	9,808	10,410	19,410	16,588
Operating income	9,808	10,410	19,410	16,588
Dedicated [Member]
Operating revenue	25,404	15,090	47,858	28,640
Operating income	2,563	1,433	4,567	2,755
Operating income	2,563	1,433	4,567	2,755
Intermodal [Member]
Operating income	969	483	2,220	966
Operating income	969	483	2,220	966
Brokerage [Member]
Operating income	821	606	1,563	1,263
Operating income	$ 821	$ 606	1,563	$ 1,263
Facility [Member]
Gain on disposition of facility			3,712
Operating revenue	$ 163,588	$ 168,423	324,875	$ 327,832
Operating income	14,161	12,932	31,472	21,572
Total operating income before gain on disposition of facility	14,161	12,932	27,760	21,572
Operating income	$ 14,161	$ 12,932	$ 31,472	$ 21,572

Represents the operating income or loss before the gain or loss on the disposition of the facility.

No definition available.

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- Definition

Amount of gain (loss) on sale or disposal of assets, including but not limited to property plant and equipment, intangible assets and equity in securities of subsidiaries or equity method investee.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 360

-SubTopic 10

-Section 45

-Paragraph 5

-URI http://asc.fasb.org/extlink&oid=51824106&loc=d3e2443-110228

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The net result for the period of deducting operating expenses from operating revenues.

+ References

No definition available.

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- Definition

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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