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, 2022	Sep. 30, 2021	Sep. 30, 2020
Defined Benefit Pension Plan [Member]
Changes in projected benefit obligation:
Projected benefit obligation at beginning of year	$ 299,364	$ 307,623
Plan amendment		611
Service cost	3,893	4,651	$ 4,524
Interest cost	6,893	6,318	6,868
Net actuarial losses (gains)	(84,607)	(9,955)
Contribution by participants	10	10
Benefits paid	(11,585)	(11,314)
Foreign currency exchange rate changes	(16,047)	1,420
Projected benefit obligation at end of year	197,921	299,364	307,623
Changes in fair value of plan assets:
Fair value of plan assets at beginning of year	291,107	266,709
Actual return on plan assets	(68,506)	31,915
Contributions by the Company	2,370	2,185
Contribution by participants	10	10
Benefits paid	(11,585)	(11,314)
Foreign currency exchange rate changes	(11,336)	1,602
Fair value of plan assets at end of year	202,060	291,107	266,709
Net over/(under) funded status at end of year	4,139	(8,257)
United States [Member] | Defined Benefit Pension Plan [Member]
Changes in projected benefit obligation:
Projected benefit obligation at beginning of year	177,346	184,077
Plan amendment		611
Service cost	1,554	1,729	1,659
Interest cost	5,281	4,957	5,590
Net actuarial losses (gains)	(43,639)	(6,496)
Benefits paid	(8,098)	(7,532)
Projected benefit obligation at end of year	132,444	177,346	184,077
Changes in fair value of plan assets:
Fair value of plan assets at beginning of year	221,263	201,555
Actual return on plan assets	(58,684)	27,240
Benefits paid	(8,098)	(7,532)
Fair value of plan assets at end of year	154,481	221,263	201,555
Net over/(under) funded status at end of year	22,037	43,917
Foreign Plan | Defined Benefit Pension Plan [Member]
Changes in projected benefit obligation:
Projected benefit obligation at beginning of year	122,018	123,546
Service cost	2,339	2,922	2,865
Interest cost	1,612	1,361	1,278
Net actuarial losses (gains)	(40,968)	(3,459)
Contribution by participants	10	10
Benefits paid	(3,487)	(3,782)
Foreign currency exchange rate changes	(16,047)	1,420
Projected benefit obligation at end of year	65,477	122,018	123,546
Changes in fair value of plan assets:
Fair value of plan assets at beginning of year	69,844	65,154
Actual return on plan assets	(9,822)	4,675
Contributions by the Company	2,370	2,185
Contribution by participants	10	10
Benefits paid	(3,487)	(3,782)
Foreign currency exchange rate changes	(11,336)	1,602
Fair value of plan assets at end of year	47,579	69,844	65,154
Net over/(under) funded status at end of year	(17,898)	(52,174)
Other Postretirement Benefit Plans [Member]
Changes in projected benefit obligation:
Projected benefit obligation at beginning of year	21,544	25,445
Service cost	1	1
Interest cost	577	599
Net actuarial losses (gains)	(3,504)	(2,422)
Contribution by participants	923	993
Benefits paid	(2,744)	(3,072)
Projected benefit obligation at end of year	16,797	21,544	$ 25,445
Changes in fair value of plan assets:
Contributions by the Company	1,821	2,079
Contribution by participants	923	993
Benefits paid	(2,744)	(3,072)
Net over/(under) funded status at end of year	$ (16,797)	$ (21,544)