Note 10 - Commitments and Contingencies (Details Textual)	Mar. 31, 2016 USD ($)
Revenue Equipment Expenditure [Member]
Contractual Obligation, Due in Next Fiscal Year	$ 122,100,000
Building Construction and Acquisition Expenditures [Member]
Contractual Obligation, Due in Next Fiscal Year	1,200,000
Operating Leases, Future Minimum Payments Due	$ 369,000

Amount of required minimum rental payments for leases having an initial or remaining non-cancelable letter-terms in excess of one year.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 10
-Section 55
-Paragraph 40
-Subparagraph (Note 3)
-URI http://asc.fasb.org/extlink&oid=6584154&loc=d3e38371-112697

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 20
-Section 50
-Paragraph 2
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6453985&loc=d3e41502-112717

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant