Retirement Benefits (Assumptions in Calculating Net Periodic Benefit Cost) (Details)	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
U.S.
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets	5.80%
International
Defined Benefit Plan Disclosure [Line Items]
Expected return on plan assets	4.80%
Defined Benefit Pension Plan | U.S.
Defined Benefit Plan Disclosure [Line Items]
Discount rate – Service cost	5.10%	6.10%	5.70%
Discount rate – Interest cost	4.70%	6.00%	5.50%
Expected return on plan assets	5.80%	5.80%	5.80%
Rate of compensation increase	3.50%	3.50%	3.50%
Defined Benefit Pension Plan | International
Defined Benefit Plan Disclosure [Line Items]
Discount rate – Service cost	4.60%	5.30%	4.60%
Discount rate – Interest cost	4.50%	5.10%	5.00%
Expected return on plan assets	4.80%	4.30%	4.20%
Rate of compensation increase	3.40%	3.40%	3.40%