Intangible Assets, Net (Schedule of Finite-Lived and Indefinite-Lived Intangible Assets by Major Class) (Details) - USD ($) $ in Thousands	Mar. 31, 2025	Sep. 30, 2024
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization of Finite-Lived Intangible	$ (434,129)	$ (440,603)
Net Carrying Amount - Finite-Lived Intangible	349,391
Intangible Assets, Gross, Total	846,315	881,022
Intangible Assets, Net, Total	412,186	440,419
Customer Relationships And Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	653,360	680,713
Accumulated Amortization of Finite-Lived Intangible	(355,649)	(360,543)
Net Carrying Amount - Finite-Lived Intangible	297,711	320,170
Intellectual Property [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	3,139	3,139
Accumulated Amortization of Finite-Lived Intangible	(3,139)	(3,139)
Process Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	126,456	131,827
Accumulated Amortization of Finite-Lived Intangible	(74,776)	(76,329)
Net Carrying Amount - Finite-Lived Intangible	51,680	55,498
Other [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	565	592
Accumulated Amortization of Finite-Lived Intangible	(565)	(592)
Trade Name [Member]
Finite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets	62,795	64,751
Aerospace [Member]
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization of Finite-Lived Intangible	(289,291)	(286,498)
Intangible Assets, Gross, Total	326,253	326,253
Intangible Assets, Net, Total	36,962	39,755
Aerospace [Member] | Customer Relationships And Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	281,683	281,683
Accumulated Amortization of Finite-Lived Intangible	(248,631)	(246,152)
Net Carrying Amount - Finite-Lived Intangible	33,052	35,531
Aerospace [Member] | Process Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	44,570	44,570
Accumulated Amortization of Finite-Lived Intangible	(40,660)	(40,346)
Net Carrying Amount - Finite-Lived Intangible	3,910	4,224
Industrial [Member]
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization of Finite-Lived Intangible	(144,838)	(154,105)
Intangible Assets, Gross, Total	520,062	554,769
Intangible Assets, Net, Total	375,224	400,664
Industrial [Member] | Customer Relationships And Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	371,677	399,030
Accumulated Amortization of Finite-Lived Intangible	(107,018)	(114,391)
Net Carrying Amount - Finite-Lived Intangible	264,659	284,639
Industrial [Member] | Intellectual Property [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	3,139	3,139
Accumulated Amortization of Finite-Lived Intangible	(3,139)	(3,139)
Industrial [Member] | Process Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	81,886	87,257
Accumulated Amortization of Finite-Lived Intangible	(34,116)	(35,983)
Net Carrying Amount - Finite-Lived Intangible	47,770	51,274
Industrial [Member] | Other [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	565	592
Accumulated Amortization of Finite-Lived Intangible	(565)	(592)
Industrial [Member] | Trade Name [Member]
Finite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets	$ 62,795	$ 64,751