Income Taxes (Deferred Tax Assets and Liabilities Included in Consolidated Financials) (Details) - USD ($) $ in Millions	Sep. 30, 2025	Sep. 30, 2024
Deferred Tax Assets
Other noncurrent assets	$ 127.9	$ 127.8
Deferred Tax Liabilities
Deferred income taxes	579.6	1,159.9
Net Deferred Income Tax Liability	$ 451.7	$ 1,032.1