Retirement Benefits (Schedule of Net Periodic Benefit Costs) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Defined Benefit Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 4,651	$ 4,524	$ 3,487
Interest cost	6,318	6,868	8,290
Expected return on plan assets	(16,626)	(15,173)	(14,624)
Amortization of: Net losses	1,472	2,476	900
Amortization of: Prior service cost (benefit)	994	959	709
Net periodic (benefit) cost	(3,191)	(346)	(1,238)
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	2	5
Interest cost	599	782	1,154
Amortization of: Net losses	30	47	55
Amortization of: Prior service cost (benefit)	1	3	(5)
Net periodic (benefit) cost	631	834	1,209
United States [Member] | Defined Benefit Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1,729	1,659	1,451
Interest cost	4,957	5,590	6,384
Expected return on plan assets	(14,144)	(12,346)	(11,986)
Amortization of: Net losses	541	1,430	617
Amortization of: Prior service cost (benefit)	969	936	709
Net periodic (benefit) cost	(5,948)	(2,731)	(2,825)
Foreign Plan | Defined Benefit Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	2,922	2,865	2,036
Interest cost	1,361	1,278	1,906
Expected return on plan assets	(2,482)	(2,827)	(2,638)
Amortization of: Net losses	931	1,046	283
Amortization of: Prior service cost (benefit)	25	23
Net periodic (benefit) cost	$ 2,757	$ 2,385	$ 1,587