Note 6 - Lease Commitments - Capital and Financing Lease Obligations (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Sep. 30, 2017
Total capital and financing lease obligations	$ 37,586	$ 33,428
Less current portion	(633)	(548)
Total capital and financing lease obligations, net of current portion	36,953	32,880
Due in Monthly Installments Through Fiscal Year 2033 [Member]
Capital lease finance obligations	28,902	26,930
Asset not under Construction, Due in Monthly Installments Through Fiscal Year 2041 [Member]
Capital lease finance obligations	4,884	4,999
Asset Under Construction Due in Monthly Installments Through Fiscal Year 2033 [Member]
Capital lease finance obligations	$ 3,800	$ 1,499

Amount equal to the present value (the principal) at the beginning of the lease term of minimum lease payments during the lease term (excluding that portion of the payments representing executory costs such as insurance, maintenance, and taxes to be paid by the lessor, together with any profit thereon) net of payments or other amounts applied to the principal through the balance sheet date.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84164817&loc=d3e45280-112737

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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