Retirement and Postretirement Benefit Plans (Schedule of Actuarial Assumptions) (Details) - Pension Plan [Member]	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Weighted average assumptions to determine benefit obligations at the measurement date:
Discount rate for obligation	2.90%	2.70%	3.20%
Rate of compensation increase	2.60%	2.60%	2.60%
Weighted average assumptions to determine benefit cost for the year:
Discount rate for expense	2.70%	3.20%	4.20%
Expected rate of return on plan assets	4.50%	5.30%	5.50%
Rate of compensation increase	2.60%	2.60%	3.00%