Retirement Benefits (Schedule of Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Defined Benefit Plan Disclosure [Line Items]
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
Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 5.2	$ 5.2
Interest cost	43.8	48.5
Expected return on plan assets	(47.9)	(41.6)
Prior service cost amortization	0.5	0.5
Actuarial loss amortization	14.1	17.5
Other	0.1	0.1
Net Periodic Cost	15.8	30.2
U.S. | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	2.3	2.4
Interest cost	29.9	33.7
Expected return on plan assets	(33.2)	(30.0)
Prior service cost amortization	0.3	0.3
Actuarial loss amortization	11.7	14.3
Other	0.0	0.0
Net Periodic Cost	11.0	20.7
International | Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	2.9	2.8
Interest cost	13.9	14.8
Expected return on plan assets	(14.7)	(11.6)
Prior service cost amortization	0.2	0.2
Actuarial loss amortization	2.4	3.2
Other	0.1	0.1
Net Periodic Cost	$ 4.8	$ 9.5