Intangible Assets, Net (Schedule of Finite-Lived and Indefinite-Lived Intangible Assets by Major Class) (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Sep. 30, 2023
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization of Finite-Lived Intangible	$ (413,940)	$ (401,150)
Net Carrying Amount - Finite-Lived Intangible	396,978
Intangible Assets, Gross, Total	874,926	853,513
Intangible Assets, Net, Total	460,986	452,363
Customer Relationships And Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	676,199	660,487
Accumulated Amortization of Finite-Lived Intangible	(337,178)	(326,227)
Net Carrying Amount - Finite-Lived Intangible	339,021	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	131,006	128,026
Accumulated Amortization of Finite-Lived Intangible	(73,049)	(71,260)
Net Carrying Amount - Finite-Lived Intangible	57,957	56,766
Other [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	574	554
Accumulated Amortization of Finite-Lived Intangible	(574)	(524)
Net Carrying Amount - Finite-Lived Intangible		30
Trade Name [Member]
Finite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets	64,008	61,307
Aerospace [Member]
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization of Finite-Lived Intangible	(278,613)	(275,694)
Intangible Assets, Gross, Total	326,253	326,253
Intangible Assets, Net, Total	47,640	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	(238,825)	(236,143)
Net Carrying Amount - Finite-Lived Intangible	42,858	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	(39,788)	(39,551)
Net Carrying Amount - Finite-Lived Intangible	4,782	5,019
Industrial [Member]
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization of Finite-Lived Intangible	(135,327)	(125,456)
Intangible Assets, Gross, Total	548,673	527,260
Intangible Assets, Net, Total	413,346	401,804
Industrial [Member] | Customer Relationships And Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	394,516	378,804
Accumulated Amortization of Finite-Lived Intangible	(98,353)	(90,084)
Net Carrying Amount - Finite-Lived Intangible	296,163	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	86,436	83,456
Accumulated Amortization of Finite-Lived Intangible	(33,261)	(31,709)
Net Carrying Amount - Finite-Lived Intangible	53,175	51,747
Industrial [Member] | Other [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	574	554
Accumulated Amortization of Finite-Lived Intangible	(574)	(524)
Net Carrying Amount - Finite-Lived Intangible		30
Industrial [Member] | Trade Name [Member]
Finite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets	$ 64,008	$ 61,307