Income Taxes (Effective Tax Rate) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Income Tax Disclosure [Abstract]
Income tax expense (benefit)	$ (515.4)	$ 159.6	$ (197.3)	$ (205.5)
Income (Loss) from continuing operations before taxes	$ (1,937.7)	$ 890.8	$ (203.4)	$ (562.0)
Effective tax rate	26.60%	17.90%	97.00%	36.60%