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Derivative Instruments and Hedging Activities - Interest Swap Contracts (Details) - Cash Flow Hedging [Member] $ in Millions	12 Months Ended
	Sep. 30, 2025 USD ($)
Interest Rate Swap Agreement One [Member]
Derivative [Line Items]
Derivative, hedge term (Year)	10 years
Derivative, notional amount	$ 25.0
Derivative, fixed interest rate	3.018%
Derivative, mark-to-market gain	$ 0.8
Interest Rate Swap Agreement Two [Member]
Derivative [Line Items]
Derivative, hedge term (Year)	10 years
Derivative, notional amount	$ 25.0
Derivative, fixed interest rate	3.40%
Derivative, mark-to-market gain	$ 0.8
Interest Rate Swap Agreement Three [Member]
Derivative [Line Items]
Derivative, hedge term (Year)	10 years
Derivative, notional amount	$ 25.0
Derivative, fixed interest rate	3.525%
Derivative, mark-to-market gain	$ 0.8
Interest Rate Swap Agreement Four [Member]
Derivative [Line Items]
Derivative, hedge term (Year)	10 years
Derivative, notional amount	$ 25.0
Derivative, fixed interest rate	3.535%
Derivative, mark-to-market gain	$ 0.8
Interest Rate Swap Agreement Five [Member]
Derivative [Line Items]
Derivative, hedge term (Year)	10 years
Derivative, notional amount	$ 25.0
Derivative, fixed interest rate	3.45%
Derivative, mark-to-market gain	$ 0.8
Interest Rate Swap Agreement Six [Member]
Derivative [Line Items]
Derivative, hedge term (Year)	10 years
Derivative, notional amount	$ 25.0
Derivative, fixed interest rate	3.541%
Derivative, mark-to-market gain	$ 0.7
Interest Rate Swap Agreement Seven [Member]
Derivative [Line Items]
Derivative, hedge term (Year)	10 years
Derivative, notional amount	$ 25.0
Derivative, fixed interest rate	3.552%
Derivative, mark-to-market gain	$ 0.8
Interest Rate Swap Agreement Eight [Member]
Derivative [Line Items]
Derivative, hedge term (Year)	10 years
Derivative, notional amount	$ 25.0
Derivative, fixed interest rate	3.426%
Derivative, mark-to-market gain	$ 0.8
Interest Rate Swap Agreement Nine [Member]
Derivative [Line Items]
Derivative, hedge term (Year)	10 years
Derivative, notional amount	$ 25.0
Derivative, fixed interest rate	3.577%
Derivative, mark-to-market gain	$ 0.8
Interest Rate Swap Agreement Ten [Member]
Derivative [Line Items]
Derivative, hedge term (Year)	10 years
Derivative, notional amount	$ 25.0
Derivative, fixed interest rate	3.45%
Derivative, mark-to-market gain	$ 0.8
Interest Rate Swap Agreement Eleven [Member]
Derivative [Line Items]
Derivative, hedge term (Year)	10 years
Derivative, notional amount	$ 25.0
Derivative, fixed interest rate	3.35%
Derivative, mark-to-market gain	$ 0.8
Interest Rate Swap Agreement Twelve [Member]
Derivative [Line Items]
Derivative, hedge term (Year)	1 year 6 months
Derivative, notional amount	$ 125.0
Derivative, fixed interest rate	3.567%
Derivative, mark-to-market gain	$ 0.2
Interest Rate Swap Agreement Thirteen [Member]
Derivative [Line Items]
Derivative, hedge term (Year)	1 year 6 months
Derivative, notional amount	$ 225.0
Derivative, fixed interest rate	3.567%
Derivative, mark-to-market gain	$ 0.4
Interest Rate Swap Agreement Fourteen [Member]
Derivative [Line Items]
Derivative, hedge term (Year)	10 years
Derivative, notional amount	$ 25.0
Derivative, fixed interest rate	3.58%
Derivative, mark-to-market gain	$ 0.3
Interest Rate Swap Agreement Fifteen [Member]
Derivative [Line Items]
Derivative, hedge term (Year)	10 years
Derivative, notional amount	$ 25.0
Derivative, fixed interest rate	3.611%
Derivative, mark-to-market gain	$ 0.3
Interest Rate Swap Agreement Sixteen [Member]
Derivative [Line Items]
Derivative, hedge term (Year)	10 years
Derivative, notional amount	$ 25.0
Derivative, fixed interest rate	3.657%
Derivative, mark-to-market gain	$ 0.3
Interest Rate Swap Agreement Seventeen [Member]
Derivative [Line Items]
Derivative, hedge term (Year)	10 years
Derivative, notional amount	$ 25.0
Derivative, fixed interest rate	3.763%
Derivative, mark-to-market gain	$ 0.5
Interest Rate Swap [Member]
Derivative [Line Items]
Derivative, notional amount	725.0
Derivative, mark-to-market gain	$ 10.7

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+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4A
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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 815
-SubTopic 20
-Name Accounting Standards Codification
-Section 25
-Paragraph 6A
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480682/815-20-25-6A

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 1: http://www.xbrl.org/2003/role/exampleRef
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