Income Taxes (Components of the Income Taxes Provision) (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Current Tax Provision
Federal	$ 38.0	$ 550.3	$ 167.6
State	5.6	109.2	41.0
Foreign	416.9	354.7	367.3
Total Current Tax Provision	460.5	1,014.2	575.9
Deferred Tax (Benefit) Provision
Federal	(497.4)	(97.8)	(12.5)
State	(95.0)	(15.0)	(5.8)
Foreign	37.6	43.5	(6.4)
Total Deferred Tax (Benefit) Provision	(554.8)	(69.3)	(24.7)
Total Income Tax (Benefit) Provision	$ (94.3)	$ 944.9	$ 551.2