Intangible Assets, Net (Schedule of Finite-Lived and Indefinite-Lived Intangible Assets by Major Class) (Details) - USD ($) $ in Thousands	Dec. 31, 2024	Sep. 30, 2024
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization of Finite-Lived Intangible	$ (422,478)	$ (440,603)
Net Carrying Amount - Finite-Lived Intangible	344,092
Intangible Assets, Gross, Total	826,895	881,022
Intangible Assets, Net, Total	404,417	440,419
Customer Relationships And Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	639,144	680,713
Accumulated Amortization of Finite-Lived Intangible	(345,766)	(360,543)
Net Carrying Amount - Finite-Lived Intangible	293,378	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	123,730	131,827
Accumulated Amortization of Finite-Lived Intangible	(73,016)	(76,329)
Net Carrying Amount - Finite-Lived Intangible	50,714	55,498
Other [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	557	592
Accumulated Amortization of Finite-Lived Intangible	(557)	(592)
Trade Name [Member]
Finite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets	60,325	64,751
Aerospace [Member]
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization of Finite-Lived Intangible	(287,894)	(286,498)
Intangible Assets, Gross, Total	326,253	326,253
Intangible Assets, Net, Total	38,359	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	(247,391)	(246,152)
Net Carrying Amount - Finite-Lived Intangible	34,292	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	(40,503)	(40,346)
Net Carrying Amount - Finite-Lived Intangible	4,067	4,224
Industrial [Member]
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization of Finite-Lived Intangible	(134,584)	(154,105)
Intangible Assets, Gross, Total	500,642	554,769
Intangible Assets, Net, Total	366,058	400,664
Industrial [Member] | Customer Relationships And Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	357,461	399,030
Accumulated Amortization of Finite-Lived Intangible	(98,375)	(114,391)
Net Carrying Amount - Finite-Lived Intangible	259,086	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	79,160	87,257
Accumulated Amortization of Finite-Lived Intangible	(32,513)	(35,983)
Net Carrying Amount - Finite-Lived Intangible	46,647	51,274
Industrial [Member] | Other [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	557	592
Accumulated Amortization of Finite-Lived Intangible	(557)	(592)
Industrial [Member] | Trade Name [Member]
Finite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets	$ 60,325	$ 64,751