v3.26.1
Debt - Other Debt and Other Items (Details) - USD ($)
Jun. 30, 2026
Sep. 30, 2025
Debt Instrument [Line Items]    
Outstanding standby letters of credit $ 0  
Other Debt | Unsecured    
Debt Instrument [Line Items]    
Current borrowing capacity 411,800,000  
Standby Letters of Credit | Other Debt    
Debt Instrument [Line Items]    
Outstanding standby letters of credit $ 906,900,000 $ 899,400,000