Business and Asset Actions (Global Cost Reduction Plan) (Details) $ in Millions	6 Months Ended		34 Months Ended
	Mar. 31, 2026 USD ($)	Mar. 31, 2025 USD ($)	Mar. 31, 2026 USD ($) position
Restructuring Cost and Reserve [Line Items]
Charge for severance and other postemployment benefits		$ 66.1
Global Cost Reduction Plan
Restructuring Cost and Reserve [Line Items]
Charge for severance and other postemployment benefits	$ 0.0		$ 207.7
Number of employees to whom involuntary termination benefits are payable | position			3,600
Restructuring Reserve [Roll Forward]
Amount accrued at beginning of period	101.6
Cash payments	(29.8)
Currency translation adjustment	(0.5)
Amount accrued at end of period	$ 71.3		$ 71.3