Retirement Plans (Schedule of Actuarial Assumptions) (Details)	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Pension plan
Plan obligations:
Discount rate	5.50%	5.10%	2.30%
Compensation increase rate	2.50%	2.50%	2.50%
Net periodic benefit cost:
Discount rate	5.10%	2.30%	2.10%
Expected long-term rate of return on plan assets	4.90%	4.20%	4.50%
Compensation increase rate	2.50%	2.50%	2.50%
Cash balance interest credit rate	4.20%	3.30%	1.90%
Postretirement plan
Plan obligations:
Discount rate	5.60%	5.10%	3.50%
Compensation increase rate	4.00%	4.00%
Net periodic benefit cost:
Discount rate	5.10%	3.50%	2.80%
Compensation increase rate	4.00%	4.00%