Employee Retirement Plans - Actuarial Assumptions for Domestic Plans (Details) - Pension Benefits	12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
Weighted-average assumptions:
Discount rate – benefit obligations	5.05%	6.09%	5.70%
Discount rate – benefit cost	6.09%	5.70%	3.13%
Expected return on plan assets	7.50%	7.50%	7.10%
Rate of increase in salary levels	3.25%	3.25%	3.25%