Note 11 - Business Segments - Operating Revenue and Operating Income by Segment (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Truckload [Member] \| Revenue, Net of Fuel Surcharge [Member]
Operating revenue	$ 85,469	$ 86,594	$ 253,514	$ 262,227
Truckload [Member] \| Fuel Surcharge Revenue [Member]
Operating revenue	9,726	11,777	25,771	40,296
Truckload [Member]
Operating revenue	95,195	98,371	279,285	302,523
Operating Income	6,509	8,204	20,400	27,614
Dedicated [Member] \| Revenue, Net of Fuel Surcharge [Member]
Operating revenue	37,669	31,477	109,833	73,941
Dedicated [Member] \| Fuel Surcharge Revenue [Member]
Operating revenue	2,967	2,937	7,175	8,331
Dedicated [Member]
Operating revenue	40,636	34,414	117,008	82,272
Operating Income	5,505	3,929	14,963	8,496
Intermodal [Member] \| Revenue, Net of Fuel Surcharge [Member]
Operating revenue	16,381	17,158	48,353	50,278
Intermodal [Member] \| Fuel Surcharge Revenue [Member]
Operating revenue	1,979	2,673	4,990	8,991
Intermodal [Member]
Operating revenue	18,360	19,831	53,343	59,269
Operating Income	1,645	1,152	5,396	3,372
Brokerage [Member]
Operating revenue	16,273	18,730	48,847	52,157
Operating Income	1,210	1,069	3,011	2,632
Facility [Member]
Gain on disposition of facility				3,712
Operating revenue	170,464	171,346	498,483	496,221
Operating Income	14,869	14,354	43,770	45,826
Total operating income before gain on disposition of facility	$ 14,869	$ 14,354	$ 43,770	$ 42,114

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=68055307&loc=d3e2443-110228

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- Definition

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=63488584&loc=d3e20235-122688

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