Retirement Plans - Schedule of Weighted-Average Assumptions used in Valuations of Pension Benefits (Details)	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
U.S. Plans
Net pension expense
Discount rate used to determine service cost	5.66%	3.16%	3.16%
Discount rate used to determine interest cost	5.49%	2.31%	2.10%
Expected return on plan assets	6.00%	6.00%	6.50%
Rate of compensation increase	4.00%	4.00%	3.25%
Benefit obligations
Discount rate	6.03%	5.64%	2.92%
Rate of compensation increase	4.00%	4.00%	3.25%
Non-U.S. Plans
Net pension expense
Discount rate used to determine service cost	4.90%	2.20%	1.90%
Discount rate used to determine interest cost	4.90%	2.20%	1.90%
Expected return on plan assets	4.40%	4.40%	5.60%
Rate of compensation increase	4.00%	3.70%	3.60%
Benefit obligations
Discount rate	5.20%	4.90%	2.20%
Rate of compensation increase	3.90%	4.00%	3.70%