Retirement Benefits (Schedule of Changes in Plan Assets and Benefit Obligations Recorded in Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2020
Defined Benefit Plan Disclosure [Line Items]
Net gain arising during the period	$ 6,318	$ 27,809	$ 20,179
Prior service cost due to plan amendment		611
Amortization of: Net losses	(720)	(1,502)	(2,523)
Prior service (cost) benefit	(1,004)	(995)	(962)
Foreign currency exchange rate changes on minimum retirement benefit liabilities	1,158	(855)	(1,672)
Defined Benefit Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Accumulated other comprehensive losses at beginning of year	19,083	45,508
Net gain arising during the period	(2,814)	(25,425)
Prior service cost due to plan amendment		611
Amortization of: Net losses	(814)	(1,472)
Prior service (cost) benefit	(1,004)	(994)
Foreign currency exchange rate changes on minimum retirement benefit liabilities	(1,151)	855
Accumulated other comprehensive losses at end of year	13,300	19,083	45,508
Defined Benefit Pension Plan [Member] | United States [Member]
Defined Benefit Plan Disclosure [Line Items]
Accumulated other comprehensive losses at beginning of year	(6,361)	14,131
Net gain arising during the period	25,898	(19,593)
Prior service cost due to plan amendment		611
Amortization of: Net losses	(259)	(541)
Prior service (cost) benefit	(981)	(969)
Accumulated other comprehensive losses at end of year	18,297	(6,361)	14,131
Defined Benefit Pension Plan [Member] | Foreign Plan
Defined Benefit Plan Disclosure [Line Items]
Accumulated other comprehensive losses at beginning of year	25,444	31,377
Net gain arising during the period	(28,712)	(5,832)
Amortization of: Net losses	(555)	(931)
Prior service (cost) benefit	(23)	(25)
Foreign currency exchange rate changes on minimum retirement benefit liabilities	(1,151)	855
Accumulated other comprehensive losses at end of year	(4,997)	25,444	31,377
Other Postretirement Benefit Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Accumulated other comprehensive losses at beginning of year	(2,815)	(362)
Net gain arising during the period	(3,504)	(2,422)
Amortization of: Net losses	94	(30)
Prior service (cost) benefit		(1)
Accumulated other comprehensive losses at end of year	$ (6,225)	$ (2,815)	$ (362)