v3.26.1
Financial Instruments and Fair Value Measurements (Narrative) (Details) - Measurement Input, Discount Rate [Member]
Jun. 30, 2026
Sep. 30, 2025
Long-Term Debt [Member] | Weighted Average [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Interest rate used to measure long-term debt 4.5 4.2
Long Term Notes Receivable from Municipalities [Member]    
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis Valuation Techniques [Line Items]    
Interest rate used to measure municipal notes 3.1 3