Pension Plans - Accounting For The Pension Plans (Details) - Pension Plan	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Defined Benefit Plan Disclosure [Line Items]
Weighted average assumptions used to determine benefit obligations at September 30 measurement date, Discount rate	4.20%	3.70%	1.00%
Weighted average assumptions used to determine benefit obligations at September 30 measurement date, Rate of increase in future compensation	3.00%	3.60%	2.80%
Weighted average assumptions used to determine net periodic pension cost for fiscal years ended September 30, Discount rate	3.70%	1.00%	1.10%
Weighted average assumptions used to determine net periodic pension costs for fiscals years ended September 30, Rate of increase of future compensation	3.60%	2.80%	2.80%
Weighted average assumptions used to determine net periodic pension cost for fiscal years ended September 30, Rate of return on plan assets	4.80%	5.00%	5.00%