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Note 10 - Derivative Instruments and Hedging Activities - Interest Swap Contracts (Details) - Cash Flow Hedging [Member] $ in Millions | 12 Months Ended
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Sep. 30, 2023 USD ($)
Interest Rate Swap Agreement One [Member] |
Derivative, hedge term (Year) | 10 years
Derivative, notional amount | $ 50.0
Derivative, fixed interest rate | 1.4918%
Derivative, mark-to-market gain | $ 2.7
Interest Rate Swap Agreement Two [Member] |
Derivative, hedge term (Year) | 10 years
Derivative, notional amount | $ 75.0
Derivative, fixed interest rate | 1.6475%
Derivative, mark-to-market gain | $ 4.0
Interest Rate Swap Agreement Three [Member] |
Derivative, hedge term (Year) | 10 years
Derivative, notional amount | $ 25.0
Derivative, fixed interest rate | 1.746%
Derivative, mark-to-market gain | $ 1.5
Interest Rate Swap Agreement Four [Member] |
Derivative, hedge term (Year) | 10 years
Derivative, notional amount | $ 50.0
Derivative, fixed interest rate | 3.448%
Derivative, mark-to-market gain | $ 2.4
Interest Rate Swap Agreement Five [Member] |
Derivative, hedge term (Year) | 10 years
Derivative, notional amount | $ 50.0
Derivative, fixed interest rate | 3.685%
Derivative, mark-to-market gain | $ 0.9
Interest Rate Swap Agreement Six [Member] |
Derivative, hedge term (Year) | 10 years
Derivative, notional amount | $ 25.0
Derivative, fixed interest rate | 3.535%
Derivative, mark-to-market gain | $ 0.5
Interest Rate Swap Agreement Seven [Member] |
Derivative, hedge term (Year) | 10 years
Derivative, notional amount | $ 25.0
Derivative, fixed interest rate | 3.385%
Derivative, mark-to-market gain | $ 0.6
Interest Rate Swap Agreement Eight [Member] |
Derivative, hedge term (Year) | 30 years
Derivative, notional amount | $ 50.0
Derivative, fixed interest rate | 2.747%
Derivative, mark-to-market gain | $ 7.8
Interest Rate Swap Agreement Nine [Member] |
Derivative, hedge term (Year) | 10 years
Derivative, notional amount | $ 25.0
Derivative, fixed interest rate | 2.902%
Derivative, mark-to-market gain | $ 2.2
Interest Rate Swap Agreement Ten [Member] |
Derivative, hedge term (Year) | 10 years
Derivative, notional amount | $ 25.0
Derivative, fixed interest rate | 3.018%
Derivative, mark-to-market gain | $ 2.0
Interest Rate Swap [Member] |
Derivative, notional amount | 400.0
Derivative, mark-to-market gain | $ 24.6

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- Definition Fixed interest rate related to the interest rate derivative. + References No definition available. + Details
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- Definition Amount of increase (decrease) in the fair value of derivatives recognized in the income statement. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 4A -Subparagraph (b)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480434/815-10-50-4A + Details
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- Definition Nominal or face amount used to calculate payment on derivative. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1B -Publisher FASB -URI https://asc.fasb.org//1943274/2147480434/815-10-50-1B Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Topic 815 -SubTopic 10 -Name Accounting Standards Codification -Section 50 -Paragraph 1A -Subparagraph (d) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480434/815-10-50-1A + Details
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- Definition Period the derivative contract is outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
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