Intangible Assets, Net (Schedule of Finite-Lived and Indefinite-Lived Intangible Assets by Major Class) (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Sep. 30, 2023
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization of Finite-Lived Intangible	$ (427,591)	$ (401,150)
Net Carrying Amount - Finite-Lived Intangible	370,232
Intangible Assets, Gross, Total	859,943	853,513
Intangible Assets, Net, Total	432,352	452,363
Customer Relationships And Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	665,201	660,487
Accumulated Amortization of Finite-Lived Intangible	(349,365)	(326,227)
Net Carrying Amount - Finite-Lived Intangible	315,836	334,260
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	128,924	128,026
Accumulated Amortization of Finite-Lived Intangible	(74,528)	(71,260)
Net Carrying Amount - Finite-Lived Intangible	54,396	56,766
Other [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	559	554
Accumulated Amortization of Finite-Lived Intangible	(559)	(524)
Net Carrying Amount - Finite-Lived Intangible		30
Trade Name [Member]
Finite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets	62,120	61,307
Intangible Assets, Net, Total	62,120
Aerospace [Member]
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization of Finite-Lived Intangible	(284,018)	(275,694)
Intangible Assets, Gross, Total	326,253	326,253
Intangible Assets, Net, Total	42,235	50,559
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	(243,833)	(236,143)
Net Carrying Amount - Finite-Lived Intangible	37,850	45,540
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	(40,185)	(39,551)
Net Carrying Amount - Finite-Lived Intangible	4,385	5,019
Industrial [Member]
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization of Finite-Lived Intangible	(143,573)	(125,456)
Intangible Assets, Gross, Total	533,690	527,260
Intangible Assets, Net, Total	390,117	401,804
Industrial [Member] | Customer Relationships And Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	383,518	378,804
Accumulated Amortization of Finite-Lived Intangible	(105,532)	(90,084)
Net Carrying Amount - Finite-Lived Intangible	277,986	288,720
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	84,354	83,456
Accumulated Amortization of Finite-Lived Intangible	(34,343)	(31,709)
Net Carrying Amount - Finite-Lived Intangible	50,011	51,747
Industrial [Member] | Other [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	559	554
Accumulated Amortization of Finite-Lived Intangible	(559)	(524)
Net Carrying Amount - Finite-Lived Intangible		30
Industrial [Member] | Trade Name [Member]
Finite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets	62,120	$ 61,307
Intangible Assets, Net, Total	$ 62,120