Financial Instruments (Carrying Amount and Cumulative Hedging Adjustment) (Details) - USD ($) $ in Millions |
Sep. 30, 2023 |
Sep. 30, 2022 |
---|---|---|
Derivative Instruments and Hedging Activities Disclosures [Line Items] | ||
Cumulative hedging adjustment, included in carrying amount | $ 80.5 | $ 77.1 |
Long-term debt | ||
Derivative Instruments and Hedging Activities Disclosures [Line Items] | ||
Carrying amounts of hedged item | 2,011.4 | 2,012.9 |
Cumulative hedging adjustment, included in carrying amount | $ (80.5) | $ (77.1) |