Retirement Benefits (Assumptions in Calculating Net Periodic Benefit Cost) (Details)	12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
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	4.30%
Defined Benefit Pension Plan | U.S.
Defined Benefit Plan Disclosure [Line Items]
Discount rate – Service cost	6.10%	5.70%	3.00%
Discount rate – Interest cost	6.00%	5.50%	2.30%
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	5.30%	4.60%	1.90%
Discount rate – Interest cost	5.10%	5.00%	1.60%
Expected return on plan assets	4.30%	4.20%	4.00%
Rate of compensation increase	3.40%	3.40%	3.30%