Retirement Benefits (Schedule of Changes in Projected Benefit Obligations, Fair Value of Plan Assets, and Funded Status of Plan) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2022
Defined Benefit Pension Plan [Member]
Changes in projected benefit obligation:
Projected benefit obligation at beginning of year	$ 194,485	$ 197,921
Plan amendment	1,121
Service cost	2,019	2,226
Interest cost	10,811	10,434
Net actuarial loss (gain)	17,377	(9,388)
Contribution by participants	12	11
Benefits paid	(12,657)	(11,831)
Foreign currency exchange rate changes	5,134	5,112
Projected benefit obligation at end of year	218,302	194,485	$ 197,921
Changes in fair value of plan assets:
Fair value of plan assets at beginning of year	206,145	202,060
Actual return on plan assets	37,248	9,928
Contributions by the Company	2,038	2,322
Contribution by participants	12	11
Benefits paid	(12,657)	(11,831)
Foreign currency exchange rate changes	4,607	3,655
Fair value of plan assets at end of year	237,393	206,145	202,060
Net over/(under) funded status at end of year	19,091	11,660
Other Postretirement Benefits Plan [Member]
Changes in projected benefit obligation:
Projected benefit obligation at beginning of year	15,336	16,797
Service cost		1	1
Interest cost	902	904	577
Net actuarial loss (gain)	597	(682)
Contribution by participants	834	873
Benefits paid	(2,466)	(2,557)
Projected benefit obligation at end of year	15,203	15,336	16,797
Changes in fair value of plan assets:
Contributions by the Company	1,632	1,684
Contribution by participants	834	873
Benefits paid	(2,466)	(2,557)
Net over/(under) funded status at end of year	(15,203)	(15,336)
United States [Member] | Defined Benefit Pension Plan [Member]
Changes in projected benefit obligation:
Projected benefit obligation at beginning of year	127,222	132,444
Plan amendment	1,121
Service cost	775	893
Interest cost	7,598	7,297
Net actuarial loss (gain)	13,249	(4,946)
Benefits paid	(9,010)	(8,466)
Projected benefit obligation at end of year	140,955	127,222	132,444
Changes in fair value of plan assets:
Fair value of plan assets at beginning of year	155,370	154,481
Actual return on plan assets	33,382	9,355
Contributions by the Company	175
Benefits paid	(9,010)	(8,466)
Fair value of plan assets at end of year	179,917	155,370	154,481
Net over/(under) funded status at end of year	38,962	28,148
Foreign Plan | Defined Benefit Pension Plan [Member]
Changes in projected benefit obligation:
Projected benefit obligation at beginning of year	67,263	65,477
Service cost	1,244	1,333
Interest cost	3,213	3,137
Net actuarial loss (gain)	4,128	(4,442)
Contribution by participants	12	11
Benefits paid	(3,647)	(3,365)
Foreign currency exchange rate changes	5,134	5,112
Projected benefit obligation at end of year	77,347	67,263	65,477
Changes in fair value of plan assets:
Fair value of plan assets at beginning of year	50,775	47,579
Actual return on plan assets	3,866	573
Contributions by the Company	1,863	2,322
Contribution by participants	12	11
Benefits paid	(3,647)	(3,365)
Foreign currency exchange rate changes	4,607	3,655
Fair value of plan assets at end of year	57,476	50,775	$ 47,579
Net over/(under) funded status at end of year	$ (19,871)	$ (16,488)