Intangible Assets, Net (Schedule of Finite-Lived and Indefinite-Lived Intangible Assets by Major Class) (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Sep. 30, 2020
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization of Finite-Lived Intangible	$ (367,324)	$ (355,644)
Net Carrying Amount - Finite-Lived Intangible	513,178
Intangible Assets, Gross, Total	949,537	962,355
Intangible Assets, Net, Total	582,213	606,711
Customer Relationships And Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	696,082	710,932
Accumulated Amortization of Finite-Lived Intangible	(259,467)	(253,565)
Net Carrying Amount - Finite-Lived Intangible	436,615	457,367
Intellectual Property [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	15,828	15,778
Accumulated Amortization of Finite-Lived Intangible	(15,828)	(15,640)
Net Carrying Amount - Finite-Lived Intangible		138
Process Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	168,354	167,316
Accumulated Amortization of Finite-Lived Intangible	(91,791)	(86,256)
Net Carrying Amount - Finite-Lived Intangible	76,563	81,060
Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	238	235
Accumulated Amortization of Finite-Lived Intangible	(238)	(183)
Net Carrying Amount - Finite-Lived Intangible		52
Tradenames [Member]
Finite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets	69,035	68,094
Aerospace [Member]
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization of Finite-Lived Intangible	(273,289)	(260,476)
Intangible Assets, Gross, Total	358,053	358,054
Intangible Assets, Net, Total	84,764	97,578
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	(206,917)	(196,520)
Net Carrying Amount - Finite-Lived Intangible	74,766	85,163
Aerospace [Member] | Process Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	76,370	76,371
Accumulated Amortization of Finite-Lived Intangible	(66,372)	(63,956)
Net Carrying Amount - Finite-Lived Intangible	9,998	12,415
Industrial [Member]
Finite-Lived Intangible Assets [Line Items]
Accumulated Amortization of Finite-Lived Intangible	(94,035)	(95,168)
Intangible Assets, Gross, Total	591,484	604,301
Intangible Assets, Net, Total	497,449	509,133
Industrial [Member] | Customer Relationships And Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	414,399	429,249
Accumulated Amortization of Finite-Lived Intangible	(52,550)	(57,045)
Net Carrying Amount - Finite-Lived Intangible	361,849	372,204
Industrial [Member] | Intellectual Property [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	15,828	15,778
Accumulated Amortization of Finite-Lived Intangible	(15,828)	(15,640)
Net Carrying Amount - Finite-Lived Intangible		138
Industrial [Member] | Process Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	91,984	90,945
Accumulated Amortization of Finite-Lived Intangible	(25,419)	(22,300)
Net Carrying Amount - Finite-Lived Intangible	66,565	68,645
Industrial [Member] | Other Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value - Finite-Lived Intangible	238	235
Accumulated Amortization of Finite-Lived Intangible	(238)	(183)
Net Carrying Amount - Finite-Lived Intangible		52
Industrial [Member] | Tradenames [Member]
Finite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets	$ 69,035	$ 68,094