Retirement Benefits (Schedule of Assumptions Used) (Details)	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Defined Benefit Pension Plan [Member] | United States [Member]
Weighted-average assumptions to determine benefit obligation:
Discount rate	3.05%	2.75%	3.25%
Weighted-average assumptions to determine periodic benefit costs:
Discount rate	2.75%	3.25%	4.35%
Long-term rate of return on plan assets	7.15%	7.39%	7.39%
Defined Benefit Pension Plan [Member] | United Kingdom
Weighted-average assumptions to determine benefit obligation:
Discount rate	2.05%	1.62%	1.74%
Rate of compensation increase	3.80%	3.30%	3.50%
Weighted-average assumptions to determine periodic benefit costs:
Long-term rate of return on plan assets	4.00%	4.75%	4.75%
Discount rate - service cost	1.71%	1.79%	2.70%
Discount rate - interest cost	1.41%	1.59%	2.51%
Rate of compensation increase	3.30%	3.50%	3.60%
Defined Benefit Pension Plan [Member] | Japan
Weighted-average assumptions to determine benefit obligation:
Discount rate	0.92%	1.10%	0.53%
Rate of compensation increase	2.00%	2.00%	2.00%
Weighted-average assumptions to determine periodic benefit costs:
Long-term rate of return on plan assets	2.00%	2.50%	2.50%
Discount rate - service cost	1.33%	0.72%	0.80%
Discount rate - interest cost	0.74%	0.31%	0.42%
Rate of compensation increase	2.00%	2.00%	2.00%
Defined Benefit Pension Plan [Member] | Germany [Member]
Weighted-average assumptions to determine benefit obligation:
Discount rate	1.36%	0.97%	0.81%
Rate of compensation increase	2.50%	2.50%	2.50%
Weighted-average assumptions to determine periodic benefit costs:
Discount rate - service cost	1.11%	1.01%	2.06%
Discount rate - interest cost	0.76%	0.56%	1.53%
Rate of compensation increase	2.50%	2.50%	2.50%
Other Postretirement Benefit Plans [Member]
Weighted-average assumptions to determine benefit obligation:
Discount rate	2.80%	2.45%	3.05%
Weighted-average assumptions to determine periodic benefit costs:
Discount rate	2.45%	3.05%	4.30%