Intangible Assets, Net (Schedule of Finite-Lived and Indefinite-Lived Intangible Assets by Major Class) (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Sep. 30, 2023
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization of Finite-Lived Intangible	$ 420,278	$ (401,150)
Net Carrying Amount - Finite-Lived Intangible	380,819
Intangible Assets, Gross, Total	863,692	853,513
Intangible Assets, Net, Total	443,414	452,363
Customer Relationships And Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	667,950	660,487
Accumulated Amortization of Finite-Lived Intangible	(342,876)	(326,227)
Net Carrying Amount - Finite-Lived Intangible	325,074	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	129,447	128,026
Accumulated Amortization of Finite-Lived Intangible	(73,702)	(71,260)
Net Carrying Amount - Finite-Lived Intangible	55,745	56,766
Other [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	561	554
Accumulated Amortization of Finite-Lived Intangible	(561)	(524)
Net Carrying Amount - Finite-Lived Intangible		30
Trade Name [Member]
Finite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets	62,595	61,307
Intangible Assets, Net, Total	62,595
Aerospace [Member]
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization of Finite-Lived Intangible	(281,539)	(275,694)
Intangible Assets, Gross, Total	326,253	326,253
Intangible Assets, Net, Total	44,714	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	(241,513)	236,143
Net Carrying Amount - Finite-Lived Intangible	40,170	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	(40,026)	(39,551)
Net Carrying Amount - Finite-Lived Intangible	4,544	5,019
Industrial [Member]
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization of Finite-Lived Intangible	(138,739)	125,456
Intangible Assets, Gross, Total	537,439	527,260
Intangible Assets, Net, Total	398,700	401,804
Industrial [Member] | Customer Relationships And Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	386,267	378,804
Accumulated Amortization of Finite-Lived Intangible	(101,363)	90,084
Net Carrying Amount - Finite-Lived Intangible	284,904	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	84,877	83,456
Accumulated Amortization of Finite-Lived Intangible	(33,676)	(31,709)
Net Carrying Amount - Finite-Lived Intangible	51,201	51,747
Industrial [Member] | Other [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	561	554
Accumulated Amortization of Finite-Lived Intangible	(561)	(524)
Net Carrying Amount - Finite-Lived Intangible		30
Industrial [Member] | Trade Name [Member]
Finite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets	62,595	$ 61,307
Intangible Assets, Net, Total	$ 62,595