Retirement Plans (Schedule of Actuarial Assumptions) (Details)	12 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Pension plan
Plan obligations:
Discount rate	4.90%	4.50%	5.50%
Compensation increase rate	2.50%	2.50%	2.50%
Net periodic benefit cost:
Discount rate	4.50%	5.50%	5.10%
Expected long-term rate of return on plan assets	5.10%	4.80%	4.90%
Compensation increase rate	2.50%	2.50%	2.50%
Cash balance interest credit rate	4.80%	4.10%	4.20%
Postretirement plan
Plan obligations:
Discount rate	4.80%	4.70%	5.60%
Compensation increase rate	4.00%	4.00%	4.00%
Net periodic benefit cost:
Discount rate	4.70%	5.60%	5.10%
Compensation increase rate	4.00%	4.00%	4.00%