Note 3 - Derivative Financial Instruments - Schedule of Interest Rate Swaps (Details)	Sep. 30, 2020 USD ($)
May 5, 2020 to May 5, 2022 [Member]
Notional amount	$ 125,000,000
Fixed rate	0.286%
May 5, 2022 to May 5, 2023 [Member]
Notional amount	$ 100,000,000
Fixed rate	0.286%
May 5, 2023 to May 7, 2024 [Member]
Notional amount	$ 75,000,000
Fixed rate	0.286%

Nominal or face amount used to calculate payment on derivative.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5580258-113959

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 1A
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=121590274&loc=SL5579245-113959

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