Retirement Benefits (Schedule of Net Periodic Benefit Costs) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Defined Benefit Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 2,226	$ 3,893	$ 4,651
Interest cost	10,434	6,893	6,318
Expected return on plan assets	(10,597)	(13,287)	(16,626)
Amortization of: Net losses (gains)	(328)	814	1,472
Amortization of: Prior service cost (benefit)	720	1,004	994
Net periodic (benefit) cost	2,455	(683)	(3,191)
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1	1	1
Interest cost	904	577	599
Amortization of: Net losses (gains)	(495)	(94)	30
Amortization of: Prior service cost (benefit)			1
Net periodic (benefit) cost	410	484	631
United States [Member] | Defined Benefit Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	893	1,554	1,729
Interest cost	7,297	5,281	4,957
Expected return on plan assets	(8,297)	(10,853)	(14,144)
Amortization of: Net losses (gains)	292	259	541
Amortization of: Prior service cost (benefit)	698	981	969
Net periodic (benefit) cost	883	(2,778)	(5,948)
Foreign Plan | Defined Benefit Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	1,333	2,339	2,922
Interest cost	3,137	1,612	1,361
Expected return on plan assets	(2,300)	(2,434)	(2,482)
Amortization of: Net losses (gains)	(620)	555	931
Amortization of: Prior service cost (benefit)	22	23	25
Net periodic (benefit) cost	$ 1,572	$ 2,095	$ 2,757