The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

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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).

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Note 17 - Business Segments (Details Textual)	3 Months Ended								12 Months Ended
Note 17 - Business Segments (Details Textual)	Dec. 31, 2015 USD ($)	Sep. 30, 2015 USD ($)	Jun. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Sep. 30, 2014 USD ($)	Jun. 30, 2014 USD ($)	Mar. 31, 2014 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($)
M W L [Member]
Equity Method Investment, Ownership Percentage	45.00%								45.00%
Logistics [Member] \| Intersegment Eliminations [Member]
Revenues											$ 2,100,000
Truckload [Member]
Revenues									$ 398,361,000	$ 448,273,000	464,959,000
Depreciation, Depletion and Amortization									53,700,000	53,000,000	54,600,000
Dedicated [Member]
Revenues									118,272,000	70,352,000	42,320,000
Depreciation, Depletion and Amortization									15,000,000	8,200,000	4,700,000
Intermodal [Member]
Revenues									76,958,000	97,092,000	92,513,000
Depreciation, Depletion and Amortization									5,400,000	6,000,000	4,300,000
Brokerage [Member]
Revenues									71,403,000	57,212,000	59,422,000
Depreciation, Depletion and Amortization									$ 1,300,000	$ 993,000	$ 845,000
Number of Operating Segments									6
Number of Reportable Segments									4	4	2
Revenues	$ 168,773,000	$ 171,346,000	$ 163,588,000	$ 161,287,000	$ 173,547,000	$ 171,550,000	$ 168,423,000	$ 159,409,000	$ 664,994,000	$ 672,929,000	$ 659,214,000