Retirement Benefits (Schedule of Assumptions Used) (Details)	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Defined Benefit Pension Plan [Member] | United States [Member]
Weighted-average assumptions to determine benefit obligation at September 30:
Discount rate	3.25%	4.35%	3.80%
Weighted-average assumptions to determine periodic benefit costs for years ending September 30:
Discount rate	4.35%	3.80%	3.65%
Long-term rate of return on plan assets	7.39%	7.39%	7.38%
Defined Benefit Pension Plan [Member] | United Kingdom
Weighted-average assumptions to determine benefit obligation at September 30:
Discount rate	1.74%	2.68%	2.56%
Rate of compensation increase	3.50%	3.60%	3.60%
Weighted-average assumptions to determine periodic benefit costs for years ending September 30:
Discount rate - service cost	2.70%	2.58%	2.33%
Discount rate - interest cost	2.51%	2.36%	2.24%
Rate of compensation increase	3.60%	3.60%	3.40%
Long-term rate of return on plan assets	4.75%	4.75%	4.75%
Defined Benefit Pension Plan [Member] | Japan
Weighted-average assumptions to determine benefit obligation at September 30:
Discount rate	0.53%	0.62%	0.58%
Rate of compensation increase	2.00%	2.00%	2.00%
Weighted-average assumptions to determine periodic benefit costs for years ending September 30:
Discount rate - service cost	0.80%	0.72%	0.59%
Discount rate - interest cost	0.42%	0.38%	0.45%
Rate of compensation increase	2.00%	2.00%	2.02%
Long-term rate of return on plan assets	2.50%	2.50%	2.50%
Defined Benefit Pension Plan [Member] | Germany [Member]
Weighted-average assumptions to determine benefit obligation at September 30:
Discount rate	0.81%	1.87%
Rate of compensation increase	2.50%	2.50%
Weighted-average assumptions to determine periodic benefit costs for years ending September 30:
Discount rate - service cost	2.06%	2.05%
Discount rate - interest cost	1.53%	1.49%
Rate of compensation increase	2.50%	2.50%
Other Postretirement Benefit Plans [Member]
Weighted-average assumptions to determine benefit obligation at September 30:
Discount rate	3.05%	4.30%	3.78%
Weighted-average assumptions to determine periodic benefit costs for years ending September 30:
Discount rate	4.30%	3.80%	3.63%