Retirement Benefits (Schedule of Net Periodic Benefit Cost) (Details) - Pension Plan - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 4.9	$ 5.2
Interest cost	43.6	43.8
Expected return on plan assets	(52.2)	(47.9)
Prior service cost amortization	0.6	0.5
Actuarial loss amortization	11.4	14.1
Other	0.3	0.1
Net Periodic Cost	$ 8.6	$ 15.8
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) Excluding Service Cost, Statement of Income or Comprehensive Income [Extensible Enumeration]	Other non-operating income (expense), net	Other non-operating income (expense), net
U.S.
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 1.9	$ 2.3
Interest cost	29.0	29.9
Expected return on plan assets	(35.2)	(33.2)
Prior service cost amortization	0.3	0.3
Actuarial loss amortization	8.9	11.7
Other	0.0	0.0
Net Periodic Cost	4.9	11.0
International
Defined Benefit Plan Disclosure [Line Items]
Service cost	3.0	2.9
Interest cost	14.6	13.9
Expected return on plan assets	(17.0)	(14.7)
Prior service cost amortization	0.3	0.2
Actuarial loss amortization	2.5	2.4
Other	0.3	0.1
Net Periodic Cost	$ 3.7	$ 4.8